LT1790 Micropower SOT-23 Low Dropout Reference Family FEATURES DESCRIPTION n High Accuracy: The LT®1790 is a family of SOT-23 micropower low dropout A Grade—0.05% Max series references that combine high accuracy and low drift B Grade—0.1% Max with low power dissipation and small package size. These n Low Drift: micropower references use curvature compensation to A Grade—10ppm/°C Max obtain a low temperature coefficient and trimmed preci- B Grade—25ppm/°C Max sion thin-film resistors to achieve high output accuracy. In n Low Thermal Hysteresis 40ppm (Typical) –40°C to 85°C addition, each LT1790 is post-package trimmed to greatly n Low Supply Current: 60µA Max reduce the temperature coefficient and increase the output n Sinks and Sources Current accuracy. Output accuracy is further assured by excellent n Low Dropout Voltage line and load regulation. Special care has been taken to n Guaranteed Operational –40°C to 125°C minimize thermally induced hysteresis. n Wide Supply Range to 18V The LT1790s are ideally suited for battery-operated n Available Output Voltage Options: 1.25V, 2.048V, systems because of their small size, low supply current 2.5V, 3V, 3.3V, 4.096V and 5V and reduced dropout voltage. These references provide n Low Profile (1mm) ThinSOT™ Package supply current and power dissipation advantages over shunt references that must idle the entire load current to APPLICATIONS operate. Since the LT1790 can also sink current, it can operate as a micropower negative voltage reference with n Handheld Instruments the same performance as a positive reference. n Negative Voltage References n Industrial Control Systems L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. n Data Acquisition Systems All other trademarks are the property of their respective owners. n Battery-Operated Equipment TYPICAL APPLICATION Positive Connection for LT1790-2.5 Typical V Distribution for LT1790-2.5 OUT 50 167 UNITS 4 6 45 2.6V ≤ VIN ≤ 18V LT1790-2.5 VOUT = 2.5V 40 0.1µF 1µF LT1790B LIMITS 1, 2 S 35 T LT1790A LIMITS 1790 TA01 UNI 30 F R O 25 E MB 20 U N 15 10 5 0 2.498 2.499 2.500 2.501 2.502 OUTPUT VOLTAGE (V) 1790 TA02 1790fc 1 For more information www.linear.com/LT1790

LT1790 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) Input Voltage .............................................................20V TOP VIEW Specified Temperature Range GND 1 6 VOUT Commercial ............................................ 0°C to 70°C GND 2 5 DNC* Industrial .............................................–40°C to 85°C DNC* 3 4 VIN Output Short-Circuit Duration ..........................Indefinite S6 PACKAGE Operating Temperature Range 6-LEAD PLASTIC TSOT-23 (Note 2) ..................................................–40°C to 125°C TJMAX = 150°C, θJA = 230°C/W Storage Temperature Range *DNC: DO NOT CONNECT (Note 3) ..................................................–65°C to 150°C Lead Temperature (Soldering, 10 sec) ...................300°C ORDER INFORMATION http://www.linear.com/product/LT1790#orderinfo LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1790ACS6-1.25#PBF LT1790ACS6-1.25#TRPBF LTXT 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-1.25#PBF LT1790AIS6-1.25#TRPBF LTXT 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-1.25#PBF LT1790BCS6-1.25#TRPBF LTXT 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-1.25#PBF LT1790BIS6-1.25#TRPBF LTXT 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-2.048#PBF LT1790ACS6-2.048#TRPBF LTXU 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-2.048#PBF LT1790AIS6-2.048#TRPBF LTXU 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-2.048#PBF LT1790BCS6-2.048#TRPBF LTXU 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-2.048#PBF LT1790BIS6-2.048#TRPBF LTXU 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-2.5#PBF LT1790ACS6-2.5#TRPBF LTPZ 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-2.5#PBF LT1790AIS6-2.5#TRPBF LTPZ 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-2.5#PBF LT1790BCS6-2.5#TRPBF LTPZ 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-2.5#PBF LT1790BIS6-2.5#TRPBF LTPZ 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-3#PBF LT1790ACS6-3#TRPBF LTQA 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-3#PBF LT1790AIS6-3#TRPBF LTQA 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-3#PBF LT1790BCS6-3#TRPBF LTQA 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-3#PBF LT1790BIS6-3#TRPBF LTQA 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-3.3#PBF LT1790ACS6-3.3#TRPBF LTXW 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-3.3#PBF LT1790AIS6-3.3#TRPBF LTXW 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-3.3#PBF LT1790BCS6-3.3#TRPBF LTXW 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-3.3#PBF LT1790BIS6-3.3#TRPBF LTXW 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-4.096#PBF LT1790ACS6-4.096#TRPBF LTQB 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-4.096#PBF LT1790AIS6-4.096#TRPBF LTQB 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-4.096#PBF LT1790BCS6-4.096#TRPBF LTQB 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-4.096#PBF LT1790BIS6-4.096#TRPBF LTQB 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-5#PBF LT1790ACS6-5#TRPBF LTQC 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-5#PBF LT1790AIS6-5#TRPBF LTQC 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-5#PBF LT1790BCS6-5#TRPBF LTQC 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-5#PBF LT1790BIS6-5#TRPBF LTQC 6-Lead Plastic TSOT-23 –40°C to 85°C 1790fc 2 For more information www.linear.com/LT1790

LT1790 ORDER INFORMATION LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1790ACS6-1.25 LT1790ACS6-1.25#TR LTXT 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-1.25 LT1790AIS6-1.25#TR LTXT 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-1.25 LT1790BCS6-1.25#TR LTXT 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-1.25 LT1790BIS6-1.25#TR LTXT 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-2.048 LT1790ACS6-2.048#TR LTXU 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-2.048 LT1790AIS6-2.048#TR LTXU 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-2.048 LT1790BCS6-2.048#TR LTXU 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-2.048 LT1790BIS6-2.048#TR LTXU 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-2.5 LT1790ACS6-2.5#TR LTPZ 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-2.5 LT1790AIS6-2.5#TR LTPZ 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-2.5 LT1790BCS6-2.5#TR LTPZ 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-2.5 LT1790BIS6-2.5#TR LTPZ 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-3 LT1790ACS6-3#TR LTQA 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-3 LT1790AIS6-3#TR LTQA 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-3 LT1790BCS6-3#TR LTQA 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-3 LT1790BIS6-3#TR LTQA 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-3.3 LT1790ACS6-3.3#TR LTXW 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-3.3 LT1790AIS6-3.3#TR LTXW 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-3.3 LT1790BCS6-3.3#TR LTXW 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-3.3 LT1790BIS6-3.3#TR LTXW 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-4.096 LT1790ACS6-4.096#TR LTQB 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-4.096 LT1790AIS6-4.096#TR LTQB 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-4.096 LT1790BCS6-4.096#TR LTQB 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-4.096 LT1790BIS6-4.096#TR LTQB 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790ACS6-5 LT1790ACS6-5#TR LTQC 6-Lead Plastic TSOT-23 0°C to 70°C LT1790AIS6-5 LT1790AIS6-5#TR LTQC 6-Lead Plastic TSOT-23 –40°C to 85°C LT1790BCS6-5 LT1790BCS6-5#TR LTQC 6-Lead Plastic TSOT-23 0°C to 70°C LT1790BIS6-5 LT1790BIS6-5#TR LTQC 6-Lead Plastic TSOT-23 –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix. 1790fc 3 For more information www.linear.com/LT1790

LT1790 AVAILABLE OPTIONS TEMPERATURE RANGE 0°C TO 70°C –40°C TO 85°C OUTPUT INITIAL TEMPERATURE VOLTAGE ACCURACY COEFFICIENT ORDER PART NUMBER ORDER PART NUMBER 1.250V 0.05% 10ppm/°C LT1790ACS6-1.25 LT1790AIS6-1.25 0.1% 25ppm/°C LT1790BCS6-1.25 LT1790BIS6-1.25 2.048V 0.05% 10ppm/°C LT1790ACS6-2.048 LT1790AIS6-2.048 0.1% 25ppm/°C LT1790BCS6-2.048 LT1790BIS6-2.048 2.500V 0.05% 10ppm/°C LT1790ACS6-2.5 LT1790AIS6-2.5 0.1% 25ppm/°C LT1790BCS6-2.5 LT1790BIS6-2.5 3.000V 0.05% 10ppm/°C LT1790ACS6-3 LT1790AIS6-3 0.1% 25ppm/°C LT1790BCS6-3 LT1790BIS6-3 3.300V 0.05% 10ppm/°C LT1790ACS6-3.3 LT1790AIS6-3.3 0.1% 25ppm/°C LT1790BCS6-3.3 LT1790BIS6-3.3 4.096V 0.05% 10ppm/°C LT1790ACS6-4.096 LT1790AIS6-4.096 0.1% 25ppm/°C LT1790BCS6-4.096 LT1790BIS6-4.096 5.000V 0.05% 10ppm/°C LT1790ACS6-5 LT1790AIS6-5 0.1% 25ppm/°C LT1790BCS6-5 LT1790BIS6-5 1.25V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at T = 25°C. C = 1µF and V = 2.6V, unless otherwise noted. A L IN PARAMETER CONDITIONS MIN TYP MAX UNITS Output Voltage (Notes 3, 4) LT1790A 1.24937 1.25 1.25062 V –0.05 0.05 % LT1790B 1.24875 1.25 1.25125 V –0.1 0.1 % LT1790AC l 1.24850 1.25 1.2515 V l –0.12 0.12 % LT1790AI l 1.24781 1.25 1.25219 V l –0.175 0.175 % LT1790BC l 1.24656 1.25 1.25344 V l –0.275 0.275 % LT1790BI l 1.24484 1.25 1.25516 V l –0.4125 0.4125 % Output Voltage Temperature Coefficient (Note 5) T ≤ T ≤ T MIN A MAX LT1790A l 5 10 ppm/°C LT1790B l 12 25 ppm/°C Line Regulation 2.6V ≤ V ≤ 18V 50 170 ppm/V IN l 220 ppm/V Load Regulation (Note 6) I Source = 5mA, V = 2.8V 100 160 ppm/mA OUT IN l 250 ppm/mA I Sink = 1mA, V = 3.2V 120 180 ppm/mA OUT IN l 250 ppm/mA Minimum Operating Voltage (Note 7) V , ∆V = 0.1% IN OUT I = 0mA 1.95 2.15 V OUT l 2.50 V I Source = 5mA l 2.90 V OUT I Sink = 1mA l 2.95 V OUT 1790fc 4 For more information www.linear.com/LT1790

LT1790 1.25V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at T = 25°C. C = 1µF and V = 2.6V, unless otherwise noted. A L IN PARAMETER CONDITIONS MIN TYP MAX UNITS Supply Current No Load 35 60 µA l 75 µA Minimum Operating Current— V = –1.25V, ±0.1% 100 125 µA OUT Negative Output (See Figure 7) Turn-On Time C = 1µF 250 µs LOAD Output Noise (Note 8) 0.1Hz ≤ f ≤ 10Hz 10 µV P-P 10Hz ≤ f ≤ 1kHz 14 µV RMS Long-Term Drift of Output Voltage (Note 9) 50 ppm/√kHr Hysteresis (Note 10) ∆T = 0°C to 70°C l 25 ppm ∆T = –40°C to 85°C l 40 ppm 2.048V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at T = 25°C. C = 1µF and V = 2.8V, unless otherwise noted. A L IN PARAMETER CONDITIONS MIN TYP MAX UNITS Output Voltage (Notes 3, 4) LT1790A 2.04697 2.048 2.04902 V –0.05 0.05 % LT1790B 2.04595 2.048 2.05005 V –0.1 0.1 % LT1790AC l 2.04554 2.048 2.05046 V l –0.12 0.12 % LT1790AI l 2.04442 2.048 2.05158 V l –0.175 0.175 % LT1790BC l 2.04237 2.048 2.05363 V l –0.275 0.275 % LT1790BI l 2.03955 2.048 2.05645 V l –0.4125 0.4125 % Output Voltage Temperature Coefficient (Note 5) T ≤ T ≤ T MIN A MAX LT1790A l 5 10 ppm/°C LT1790B l 12 25 ppm/°C Line Regulation 2.8V ≤ V ≤ 18V 50 170 ppm/V IN l 220 ppm/V Load Regulation (Note 6) I Source = 5mA 120 200 ppm/mA OUT l 280 ppm/mA I Sink = 3mA 130 260 ppm/mA OUT l 450 ppm/mA Dropout Voltage (Note 7) V – V , ∆V = 0.1% IN OUT OUT I = 0mA 50 100 mV OUT l 500 mV I Source = 5mA l 750 mV OUT I Sink = 3mA l 450 mV OUT Supply Current No Load 35 60 µA l 75 µA Minimum Operating Current— V = –2.048V, 0.1% 100 125 µA OUT Negative Output (See Figure 7) Turn-On Time C = 1µF 350 µs LOAD 1790fc 5 For more information www.linear.com/LT1790

LT1790 2.048V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at T = 25°C. C = 1µF and V = 2.8V, unless otherwise noted. A L IN PARAMETER CONDITIONS MIN TYP MAX UNITS Output Noise (Note 8) 0.1Hz ≤ f ≤ 10Hz 22 µV P-P 10Hz ≤ f ≤ 1kHz 41 µV RMS Long-Term Drift of Output Voltage (Note 9) 50 ppm/√kHr Hysteresis (Note 10) ∆T = 0°C to 70°C l 25 ppm ∆T = –40°C to 85°C l 40 ppm 2.5V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at T = 25°C. C = 1µF and V = 3V, unless otherwise noted. A L IN PARAMETER CONDITIONS MIN TYP MAX UNITS Output Voltage (Notes 3, 4) LT1790A 2.49875 2.5 2.50125 V –0.05 0.05 % LT1790B 2.4975 2.5 2.5025 V –0.1 0.1 % LT1790AC l 2.4970 2.5 2.5030 V l –0.12 0.12 % LT1790AI l 2.49563 2.5 2.50438 V l –0.175 0.175 % LT1790BC l 2.49313 2.5 2.50688 V l –0.275 0.275 % LT1790BI l 2.48969 2.5 2.51031 V l –0.4125 0.4125 % Output Voltage Temperature Coefficient (Note 5) T ≤ T ≤ T MIN A MAX LT1790A l 5 10 ppm/°C LT1790B l 12 25 ppm/°C Line Regulation 3V ≤ V ≤ 18V 50 170 ppm/V IN l 220 ppm/V Load Regulation (Note 6) I Source = 5mA 80 160 ppm/mA OUT l 250 ppm/mA I Sink = 3mA 70 110 ppm/mA OUT l 300 ppm/mA Dropout Voltage (Note 7) V – V , ∆V = 0.1% IN OUT OUT I = 0mA 50 100 mV OUT l 120 mV I Source = 5mA l 450 mV OUT I Sink = 3mA l 250 mV OUT Supply Current No Load 35 60 µA l 80 µA Minimum Operating Current— V = –2.5V, 0.1% 100 125 µA OUT Negative Output (See Figure 7) Turn-On Time C = 1µF 700 µs LOAD Output Noise (Note 8) 0.1Hz ≤ f ≤ 10Hz 32 µV P-P 10Hz ≤ f ≤ 1kHz 48 µV RMS Long-Term Drift of Output Voltage (Note 9) 50 ppm/√kHr Hysteresis (Note 10) ∆T = 0°C to 70°C l 25 ppm ∆T = –40°C to 85°C l 40 ppm 1790fc 6 For more information www.linear.com/LT1790

LT1790 3V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at T = 25°C. C = 1µF and V = 3.5V, unless otherwise noted. A L IN PARAMETER CONDITIONS MIN TYP MAX UNITS Output Voltage (Notes 3, 4) LT1790A 2.9985 3 3.0015 V –0.05 0.05 % LT1790B 2.9970 3 3.0030 V –0.10 0.10 % LT1790AC l 2.99640 3 3.00360 V l –0.12 0.12 % LT1790AI l 2.99475 3 3.00525 V l –0.175 0.175 % LT1790BC l 2.99175 3 3.00825 V l –0.275 0.275 % LT1790BI l 2.98763 3 3.01238 V l –0.4125 0.4125 % Output Voltage Temperature Coefficient (Note 5) T ≤ T ≤ T MIN A MAX LT1790A l 5 10 ppm/°C LT1790B l 12 25 ppm/°C Line Regulation 3.5V ≤ V ≤ 18V 50 170 ppm/V IN l 220 ppm/V Load Regulation (Note 6) I Source = 5mA 80 160 ppm/mA OUT l 250 ppm/mA I Sink = 3mA 70 110 ppm/mA OUT l 300 ppm/mA Dropout Voltage (Note 7) V – V , ∆V = 0.1% IN OUT OUT I = 0mA 50 100 mV OUT l 120 mV I Source = 5mA l 450 mV OUT I Sink = 3mA l 250 mV OUT Supply Current No Load 35 60 µA l 80 µA Minimum Operating Current— V = –3V, 0.1% 100 125 µA OUT Negative Output (See Figure 7) Turn-On Time C = 1µF 700 µs LOAD Output Noise (Note 8) 0.1Hz ≤ f ≤ 10Hz 50 µV P-P 10Hz ≤ f ≤ 1kHz 56 µV RMS Long-Term Drift of Output Voltage (Note 9) 50 ppm/√kHr Hysteresis (Note 10) ∆T = 0°C to 70°C l 25 ppm ∆T = –40°C to 85°C l 40 ppm 1790fc 7 For more information www.linear.com/LT1790

LT1790 3.3V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at T = 25°C. C = 1µF and V = 3.8V, unless otherwise noted. A L IN PARAMETER CONDITIONS MIN TYP MAX UNITS Output Voltage (Notes 3, 4) LT1790A 3.29835 3.3 3.30165 V –0.05 0.05 % LT1790B 3.2967 3.3 3.3033 V –0.10 0.10 % LT1790AC l 3.29604 3.3 3.30396 V l –0.120 0.120 % LT1790AI l 3.29423 3.3 3.30578 V l –0.175 0.175 % LT1790BC l 3.29093 3.3 3.30908 V l –0.275 0.275 % LT1790BI l 3.28639 3.3 3.31361 V l –0.4125 0.4125 % Output Voltage Temperature Coefficient (Note 5) T ≤ T ≤ T MIN A MAX LT1790A l 5 10 ppm/°C LT1790B l 12 25 ppm/°C Line Regulation 3.8V ≤ V ≤ 18V 50 170 ppm/V IN l 220 ppm/V Load Regulation (Note 6) I Source = 5mA 80 160 ppm/mA OUT l 250 ppm/mA I Sink = 3mA 70 110 ppm/mA OUT l 300 ppm/mA Dropout Voltage (Note 7) V – V , ∆V = 0.1% IN OUT OUT I = 0mA 50 100 mV OUT l 120 mV I Source = 5mA l 450 mV OUT I Sink = 3mA l 250 mV OUT Supply Current No Load 35 60 µA l 80 µA Minimum Operating Current— V = –3.3V, 0.1% 100 125 µA OUT Negative Output (See Figure 7) Turn-On Time C = 1µF 700 µs LOAD Output Noise (Note 8) 0.1Hz ≤ f ≤ 10Hz 50 µV P-P 10Hz ≤ f ≤ 1kHz 67 µV RMS Long-Term Drift of Output Voltage (Note 9) 50 ppm/√kHr Hysteresis (Note 10) ∆T = 0°C to 70°C l 25 ppm ∆T = –40°C to 85°C l 40 ppm 1790fc 8 For more information www.linear.com/LT1790

LT1790 4.096V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at T = 25°C. C = 1µF and V = 4.6V, unless otherwise noted. A L IN PARAMETER CONDITIONS MIN TYP MAX UNITS Output Voltage (Notes 3, 4) LT1790A 4.094 4.096 4.098 V –0.05 0.05 % LT1790B 4.092 4.096 4.10 V –0.10 0.10 % LT1790AC l 4.09108 4.096 4.10092 V l –0.120 0.120 % LT1790AI l 4.08883 4.096 4.10317 V l –0.175 0.175 % LT1790BC l 4.08474 4.096 4.10726 V l –0.275 0.275 % LT1790BI l 4.07910 4.096 4.11290 V l –0.4125 0.4125 % Output Voltage Temperature Coefficient (Note 5) T ≤ T ≤ T MIN A MAX LT1790A l 5 10 ppm/°C LT1790B l 12 25 ppm/°C Line Regulation 4.6V ≤ V ≤ 18V 50 170 ppm/V IN l 220 ppm/V Load Regulation (Note 6) I Source = 5mA 80 160 ppm/mA OUT l 250 ppm/mA I Sink = 3mA 70 110 ppm/mA OUT l 300 ppm/mA Dropout Voltage (Note 7) V – V , ∆V = 0.1% IN OUT OUT I = 0mA 50 100 mV OUT l 120 mV I Source = 5mA l 450 mV OUT I Sink = 3mA l 250 mV OUT Supply Current No Load 35 60 µA l 80 µA Minimum Operating Current— V = –4.096V, 0.1% 100 125 µA OUT Negative Output (See Figure 7) Turn-On Time C = 1µF 700 µs LOAD Output Noise (Note 8) 0.1Hz ≤ f ≤ 10Hz 60 µV P-P 10Hz ≤ f ≤ 1kHz 89 µV RMS Long-Term Drift of Output Voltage (Note 9) 50 ppm/√kHr Hysteresis (Note 10) ∆T = 0°C to 70°C l 25 ppm ∆T = –40°C to 85°C l 40 ppm 1790fc 9 For more information www.linear.com/LT1790

LT1790 5V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at T = 25°C. C = 1µF and V = 5.5V, unless otherwise noted. A L IN PARAMETER CONDITIONS MIN TYP MAX UNITS Output Voltage (Notes 3, 4) LT1790A 4.9975 5 5.0025 V –0.05 0.05 % LT1790B 4.995 5 5.005 V –0.10 0.10 % LT1790AC l 4.99400 5 5.00600 V l –0.120 0.120 % LT1790AI l 4.99125 5 5.00875 V l –0.175 0.175 % LT1790BC l 4.98625 5 5.01375 V l –0.275 0.275 % LT1790BI l 4.97938 5 5.02063 V l –0.4125 0.4125 % Output Voltage Temperature Coefficient (Note 5) T ≤ T ≤ T MIN A MAX LT1790A l 5 10 ppm/°C LT1790B l 12 25 ppm/°C Line Regulation 5.5V ≤ V ≤ 18V 50 170 ppm/V IN l 220 ppm/V Load Regulation (Note 6) I Source = 5mA 80 160 ppm/mA OUT l 250 ppm/mA I Sink = 3mA 70 110 ppm/mA OUT l 300 ppm/mA Dropout Voltage (Note 7) V – V , ∆V = 0.1% IN OUT OUT I = 0mA 50 100 mV OUT l 120 mV I Source = 5mA l 450 mV OUT I Sink = 3mA l 250 mV OUT Supply Current No Load 35 60 µA l 80 µA Minimum Operating Current— V = –5V, 0.1% 100 125 µA OUT Negative Output (See Figure 7) Turn-On Time C = 1µF 700 µs LOAD Output Noise (Note 8) 0.1Hz ≤ f ≤ 10Hz 80 µV P-P 10Hz ≤ f ≤ 1kHz 118 µV RMS Long-Term Drift of Output Voltage (Note 9) 50 ppm/√kHr Hysteresis (Note 10) ∆T = 0°C to 70°C l 25 ppm ∆T = –40°C to 85°C l 40 ppm Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 4: ESD (Electrostatic Discharge) sensitive device. Extensive use of may cause permanent damage to the device. Exposure to any Absolute ESD protection devices are used internal to the LT1790, however, high Maximum Rating condition for extended periods may affect device electrostatic discharge can damage or degrade the device. Use proper ESD reliability and lifetime. handling precautions. Note 2: The LT1790 is guaranteed functional over the operating Note 5: Temperature coefficient is measured by dividing the change in temperature range of –40°C to 125°C. The LT1790-1.25 at 125°C is output voltage by the specified temperature range. Incremental slope is typically less than 2% above the nominal voltage. The other voltage also measured at 25°C. options are typically less than 0.25% above their nominal voltage. Note 6: Load regulation is measured on a pulse basis from no load to the Note 3: If the part is stored outside of the specified temperature range, the specified load current. Output changes due to die temperature change output voltage may shift due to hysteresis. must be taken into account separately. Note 7: Excludes load regulation errors. 1790fc 10 For more information www.linear.com/LT1790

LT1790 ELECTRICAL CHARACTERISTICS Note 8: Peak-to-peak noise is measured with a single pole highpass filter Note 10: Hysteresis in the output voltage is created by package stress that at 0.1Hz and a 2-pole lowpass filter at 10Hz. The unit is enclosed in a still differs depending on whether the IC was previously at a higher or lower air environment to eliminate thermocouple effects on the leads. The test temperature. Output voltage is always measured at 25°C, but the IC is time is 10 seconds. Integrated RMS noise is measured from 10Hz to 1kHz cycled to 85°C or –40°C before a successive measurements. Hysteresis with the HP3561A analyzer. is roughly proportional to the square of the temperature change. Note 9: Long-term drift typically has a logarithmic characteristic and Hysteresis is not a problem for operational temperature excursions where therefore changes after 1000 hours tend to be smaller than before that the instrument might be stored at high or low temperature. See the time. Long-term drift is affected by differential stress between the IC and Applications Information section. the board material created during board assembly. See the Applications Information section. 1.25V TYPICAL PERFORMANCE CHARACTERISTICS Each of the voltage options have similar performance curves. For the 3V, 3.3V and the 4.096V options, the curves can be estimated based on the 2.5V and 5V curves. Minimum Input-Output Voltage Minimum Input-Output Voltage Output Voltage Temperature Drift Differential (Sourcing) Differential (Sinking) 1.253 10 1.0 FOUR TYPICAL PARTS 0.9 1.252 VOLTAGE (V)11..225501 URRENT (mA) 1 TA = 125°C TA = –55°C FFERENTIAL (V) 0000....5786 100µ1AmA 5mA OUTPUT 1.249 OUTPUT C TA = 25°C OLTAGE DI 00..34 V 0.2 1.248 0.1 1.247 0.1 0 –50 –30 –10 10 30 50 70 90 110 0 0.5 1 1.5 2 2.5 –50 –30 –10 10 30 50 70 90 110 130 TEMPERATURE (°C) INPUT-OUTPUT VOLTAGE (V) TEMPERATURE (°C) 17091.25 G01 17901.25 G02 17091.25 G03 Load Regulation (Sourcing) Load Regulation (Sinking) Supply Current vs Input Voltage 0 2000 100 TA = –55°C –200 1800 90 m) m) TA = –55°C p –400 p 1600 80 PUT VOLTAGE CHANGE (p––––1–11628400000000000 TA = 12T5A° C= 25°C PUT VOLTAGE CHANGE (p 111482600000000000 TTAA == –15255°°CC SUPPLY CURRENT (µA) 6457300000 TA = T1A2 5=° C25°C UT–1600 UT 400 20 O O –1800 200 TA = 25°C 10 –2000 0 0 0.1 1 10 0.1 1 10 0 5 10 15 20 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) INPUT VOLTAGE (V) 17901.25 G04 17901.25 G05 17901.25 G06 1790fc 11 For more information www.linear.com/LT1790

LT1790 1.25V TYPICAL PERFORMANCE CHARACTERISTICS Each of the voltage options have similar performance curves. For the 3V, 3.3V and the 4.096V options, the curves can be estimated based on the 2.5V and 5V curves. Power Supply Rejection Ratio Line Regulation vs Frequency Output Impedance vs Frequency 1.285 10 500 VIN = 3V VIN = 3V OUTPUT VOLTAGE (V)111111111.........222222222678674455000555005 TTTAAA == = –1 252555°°°CCC R SUPPLY REJECTION RATIO (dB)–––––––671423500000000 CL = 1µF OUTPUT IMPEDANCE (Ω)110100 CLC L= =4 .17µµFF CL = 0.47µF 1.235 WE O–80 1.230 P 1.225 –90 0 0 2 4 6 8 10 12 14 16 18 20 100 1k 10k 100k 1M 100 1k 10k 100k INPUT VOLTAGE (V) FREQUENCY (Hz) FREQUENCY (Hz) 17901.25. G07 17901.25 G08 17901.25 G09 Long-Term Drift –1.25V Characteristics (Data Points Reduced After 500 Hr) Output Noise 0.1Hz to 10Hz 0.30 140 R1 10k LT1790S6-1.25V 4 3V 120 2 TYPICAL PARTS SOLDERED TO PCB 0.25 TA = 30°C LT1790-1.25 100 6 V) mA)0.20 1 2 VOUT 80 V/DI NT IN R (L0.15 –VEER5kL 1µF ppm 6400 NOISE (5µ CURRE0.10 TA = 25°C 200 UTPUT TA = 125°C –20 O 0.05 TA = –55°C –40 0 –60 –2.5 –2.0 –1.5 –1.0 –0.5 0 0 200 400 600 800 1000 0 1 2 3 4 5 6 7 8 9 10 OUTPUT TO GROUND VOLTAGE (V) HOURS TIME (SEC) 17091.25 G10 17901.25 G11 17901.25 G12 Output Voltage Noise Spectrum Integrated Noise 10Hz to 1kHz 5.0 100 CL = 1µF 4.5 NOISE VOLTAGE (µV/√Hz) 334212......050055 IO =IIO O2 =5= 0 01µµ0AA0µA TEGRATED NOISE (µV)RMS 10 1.0 IN 0.5 IO = 1mA 0 1 10 100 1k 10k 10 100 1000 FREQUENCY (Hz) FREQUENCY (Hz) 17901.25 G13 17901.25 G14 1790fc 12 For more information www.linear.com/LT1790

LT1790 2.048V TYPICAL PERFORMANCE CHARACTERISTICS Each of the voltage options have similar performance curves. For the 3V, 3.3V and the 4.096V options, the curves can be estimated based on the 2.5V and 5V curves. Minimum Input-Output Voltage Minimum Input-Output Voltage Output Voltage Temperature Drift Differential (Sourcing) Differential (Sinking) 2.056 10 130 FOUR TYPICAL PARTS 2.054 TA = 25°C TA = 125°C 110 V) 90 UT VOLTAGE (V)222...000554208 T CURRENT (mA) 1 TA = –55°C DIFFERENTIAL (m 357000 1mA5mA OUTP2.046 OUTPU OLTAGE –1100 100µA V 2.044 –30 2.042 0.1 –50 –50 –30 –10 10 30 50 70 90 110 130 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 –50 –30 –10 10 30 50 70 90 110 130 TEMPERATURE (°C) INPUT-OUTPUT VOLTAGE (V) TEMPERATURE (°C) 17902.048 G01 17902.048 G02 17902.048 G03 Load Regulation (Sourcing) Load Regulation (Sinking) Supply Current vs Input Voltage 0 2000 80 TA = –55°C pm) ––420000 TA = 25°C pm) 11680000 70 TA = –55°C GE CHANGE (p–––1680000000 TA = 125°C GE CHANGE (p 111420000000 TA = –40°C URRENT (µA) 456000 TA = 25°C A A C T VOLT––11240000 T VOLT 860000 UPPLY 30 TA = 125°C PU PU TA = 125°C S 20 OUT––11680000 OUT 420000 TA = 25°C 10 –2000 0 0 0.1 1 10 0.1 1 10 0 5 10 15 20 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) INPUT VOLTAGE (V) 17902.048 G04 17902.048 G05 17902.048 G06 Power Supply Rejection Ratio Line Regulation vs Frequency Output Impedance vs Frequency 2.054 20 1000 CL = 1µF B) 10 2.052 TA = 125°C O (d 0 OUTPUT VOLTAGE (V)2222....000054440864 TTAA = = – 2555°°CC ER SUPPLY REJECTION RATI––––––614235000000 OUTPUT IMPEDANCE (Ω)11000 CCLL == 41.µ7FµF CL = 0.47µF W O–70 P 2.042 –80 1 0 2 4 6 8 10 12 14 16 18 20 100 1k 10k 100k 1M 100 1k 10k 100k INPUT VOLTAGE (V) FREQUENCY (Hz) FREQUENCY (Hz) 17902.048 G07 17902.048 G08 17902.048 G09 1790fc 13 For more information www.linear.com/LT1790

LT1790 2.048V TYPICAL PERFORMANCE CHARACTERISTICS Each of the voltage options have similar performance curves. For the 3V, 3.3V and the 4.096V options, the curves can be estimated based on the 2.5V and 5V curves. –2.048V Characteristics Long-Term Drift 0.30 100 R1 10k TA = 30°C 4 3V 80 2 TYPICAL PARTS SOLDERED TO PCB 0.25 LT1790-2.048 60 6 mA)0.20 1 2 VOUT 40 R (L R5kL 1µF 20 T IN 0.15 –VEE ppm 0 N RE –20 CUR0.10 TTAA == 12255°C°C –40 0.05 TA = –55°C –60 –80 0 –100 –4 –3.5 –3 –2.5 –2 –1.5 –1 –0.5 0 0 200 400 600 800 1000 OUTPUT TO GROUND VOLTAGE (V) HOURS 17092.048 G10 17902.048 G11 Output Noise 0.1Hz to 10Hz Output Voltage Noise Spectrum 10 CL = 1µF 9 8 SE (10µV/DIV) AGE (V/√Hz)μ 675 T NOI VOLT 4 IO = 100µA OUTPU NOISE 3 IO I=O 2=5 00µµAA 2 1 IO = 1mA 0 0 1 2 3 4 5 6 7 8 9 10 10 100 1k 10k TIME (SEC) FREQUENCY (Hz) 17902.048 G12 17902.048 G13 Integrated Noise 10Hz to 1kHz 100 )S M R V µ E ( S NOI 10 D E T A R G E T N I 1 10 100 1000 FREQUENCY (Hz) 17902.048 G14 1790fc 14 For more information www.linear.com/LT1790

LT1790 2.5V TYPICAL PERFORMANCE CHARACTERISTICS Each of the voltage options have similar performance curves. For the 3V, 3.3V and the 4.096V options, the curves can be estimated based on the 2.5V and 5V curves. Minimum Input-Output Voltage Minimum Input-Output Voltage Output Voltage Temperature Drift Differential (Sourcing) Differential (Sinking) 2.508 10 90 FOUR TYPICAL PARTS 2.506 70 V) UT VOLTAGE (V)222...555000420 T CURRENT (mA) 1 TA = –55°C TA =T A2 5=° C125°C DIFFERENTIAL (m 5300 100µA TP PU GE 10 OU2.498 OUT OLTA 5mA1mA 2.496 V–10 2.494 0.1 –30 –50 –30 –10 10 30 50 70 90 110 130 0 0.1 0.2 0.3 0.4 0.5 0.6 –50–30 –10 10 30 50 70 90 110 130 TEMPERATURE (°C) INPUT-OUTPUT VOLTAGE (V) TEMPERATURE (°C) 17902.5 G01 17902.5 G02 17902.5 G03 Load Regulation (Sourcing) Load Regulation (Sinking) Supply Current vs Input Voltage 0 2000 80 –200 1800 pm) –400 TA = 25°C pm) 1600 70 TA = –55°C GE CHANGE (p–––1680000000 TA = 125°CTA = –55°C GE CHANGE (p 111420000000 URRENT (µA) 456000 TA = 25°C A A C T VOLT––11240000 T VOLT 860000 TA = –55°C UPPLY 30 TA = 125°C PU PU S 20 T–1600 T 400 OU–1800 OU 200 TA = 125°C 10 TA = 25°C –2000 0 0 0.1 1 10 0.1 1 10 0 5 10 15 20 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) INPUT VOLTAGE (V) 17902.5 G04 17902.5 G05 17902.5 G06 Power Supply Rejection Ratio Line Regulation vs Frequency Output Impedance vs Frequency 2.515 20 1000 CL = 1µF TA = 125°C dB) 10 2.510 O ( 0 CL = 0.47µF TAGE (V)2.505 TA = 25°C CTION RATI––2100 DANCE (Ω)100 CL = 1µF OUTPUT VOL222...544099050 TA = –55°C ER SUPPLY REJE––––43560000 OUTPUT IMPE 10 CL = 4.7µF W O–70 P 2.489 –80 1 0 2 4 6 8 10 12 14 16 18 20 100 1k 10k 100k 1M 100 1k 10k 100k INPUT VOLTAGE (V) FREQUENCY (Hz) FREQUENCY (Hz) 17902.5 G07 17902.5 G08 17902.5 G09 1790fc 15 For more information www.linear.com/LT1790

LT1790 2.5V TYPICAL PERFORMANCE CHARACTERISTICS Each of the voltage options have similar performance curves. For the 3V, 3.3V and the 4.096V options, the curves can be estimated based on the 2.5V and 5V curves. Long-Term Drift –2.5V Characteristics (Data Points Reduced After 500 Hr) 0.30 140 R1 10k TA = 30°C 4 3V 120 2 TYPICAL PARTS SOLDERED TO PCB 0.25 LT1790-2.5 100 6 mA)0.20 1, 2 VOUT 80 R (L 5RkL 1µF 60 T IN 0.15 –VEE ppm 40 N E 20 R R 0.10 CU 0 TA = 25°C –20 0.05 TA = 125°C TA = –55°C –40 0 –60 –4.0 –3.5 –3.0 –2.5 –2.0 –1.5 –1.0 –0.5 0 0 200 400 600 800 1000 OUTPUT TO GROUND VOLTAGE (V) HOURS 17902.5 G10 17902.5 G11 Output Noise 0.1Hz to 10Hz Output Voltage Noise Spectrum 10 CL = 1µF 8 DIV) Hz) E (10µV/ GE (µV/√ 6 IO = 0µA OIS LTA IO = 250µA UT N E VO 4 P S OUT NOI IO = 1mA 2 0 0 1 2 3 4 5 6 7 8 9 10 10 100 1k 10k TIME (SEC) FREQUENCY (Hz) 17902.5 G13 17902.5 G12 Integrated Noise 10Hz to 1kHz 100 )S M R V µ E ( S NOI 10 D E T A R G E T N I 1 10 100 1000 FREQUENCY (Hz) 17902.5 G14 1790fc 16 For more information www.linear.com/LT1790

LT1790 5V TYPICAL PERFORMANCE CHARACTERISTICS Each of the voltage options have similar performance curves. For the 3V, 3.3V and the 4.096V options, the curves can be estimated based on the 2.5V and 5V curves. Minimum Input-Output Voltage Minimum Input-Output Voltage Output Voltage Temperature Drift Differential (Sourcing) Differential (Sinking) 5.025 10 90 FOUR TYPICAL PARTS 5.020 70 V) LTAGE (V) 55..001105 RENT (mA) TA = –55°C TA = 125°C RENTIAL (m 3500 100µA VO 5.005 UR 1 TA = 25°C FE OUTPUT 5.000 UTPUT C TAGE DIF–1100 1mA 4.995 O OL 5mA V –30 4.990 4.985 0.1 –50 –50 –30 –10 10 30 50 70 90 110 130 0 0.1 0.2 0.3 0.4 0.5 0.6 –50 –30 –10 10 30 50 70 90 110 130 TEMPERATURE (°C) INPUT-OUTPUT VOLTAGE (V) TEMPERATURE (°C) 17905 G01 17905 G02 17905 G03 Load Regulation (Sourcing) Load Regulation (Sinking) Supply Current vs Input Voltage 0 2000 80 TA = –55°C –200 1800 CHANGE (ppm) –––468000000 TA =T A1 2=5 2°C5°C CHANGE (ppm) 111642000000 RENT (µA) 567000 TTAA == –2555°°CC GE –1000 GE 1000 UR 40 T VOLTA––11240000 T VOLTA 860000 TA = –40°C UPPLY C 30 TA = 125°C PU PU S 20 T–1600 T 400 OU–1800 OU 200 TA = 125°C 10 TA = 25°C –2000 0 0 0.1 1 10 0.1 1 10 0 5 10 15 20 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) INPUT VOLTAGE (V) 17905 G04 17905 G05 17905 G06 Power Supply Rejection Ratio Line Regulation vs Frequency Output Impedance vs Frequency 5.04 20 1000 TA = 125°C B) 10 CL = 1µF d 5.02 O ( 0 OUTPUT VOLTAGE (V)5444....09990864 TTAA = = – 2555°°CC ER SUPPLY REJECTION RATI––––––614235000000 OUTPUT IMPEDANCE (Ω)11000 CL = 4.7µF CL = 0.47CµLF = 1µF W O–70 P 4.92 –80 1 0 2 4 6 8 10 12 14 16 18 20 100 1k 10k 100k 1M 100 1k 10k 100k INPUT VOLTAGE (V) FREQUENCY (Hz) FREQUENCY (Hz) 17905 G07 17905 G08 17905 G09 1790fc 17 For more information www.linear.com/LT1790

LT1790 5V TYPICAL PERFORMANCE CHARACTERISTICS Each of the voltage options have similar performance curves. For the 3V, 3.3V and the 4.096V options, the curves can be estimated based on the 2.5V and 5V curves. –5V Characteristics Long-Term Drift 0.30 100 R1 10k TA = 30°C 4 5.5V 80 2 TYPICAL PARTS SOLDERED TO PCB 0.25 LT1790-5 60 6 mA)0.20 1 2 VOUT 40 R (L R5kL 1µF 20 T IN 0.15 –VEE ppm 0 N RE –20 CUR0.10 –40 TA = 125°C –60 0.05 TA = 25°C –80 TA = –55°C 0 –100 –10 –9 –8 –7 –6 –5 –4 –3 –2 –1 0 0 200 400 600 800 1000 OUTPUT TO GROUND VOLTAGE (V) HOURS 17905 G10 17905 G11 Output Noise 0.1Hz to 10Hz Output Voltage Noise Spectrum 10 CL = 1µF 8 DIV) Hz) µV/ V/√ E (20 GE (µ 6 IO = 0µA OIS LTA IO = 250µA UT N E VO 4 P S OUT NOI IO = 1mA 2 0 0 1 2 3 4 5 6 7 8 9 10 10 100 1k 10k TIME (SEC) FREQUENCY (Hz) 17905 G13 17905 G12 Integrated Noise 10Hz to 1kHz 1000 )S M R µV 100 E ( S OI N D E T A R 10 G E T N I 1 10 100 1000 FREQUENCY (Hz) 17905 G14 1790fc 18 For more information www.linear.com/LT1790

LT1790 APPLICATIONS INFORMATION Bypass and Load Capacitors Figure 1 shows the turn-on time for the LT1790-2.5 with a 1µF input bypass and 1µF load capacitor. Figure 2 shows The LT1790 voltage references should have an input bypass the output response to a 0.5V transient on V with the capacitor of 0.1µF or larger, however the bypassing of other IN same capacitors. local devices may serve as the required component. These references also require an output capacitor for stability. The test circuit of Figure 3 is used to measure the stability The optimum output capacitance for most applications of various load currents. With R = 1k, the 1V step produces L is 1µF, although larger values work as well. This capaci- a current step of 1mA. Figure 4 shows the response to a tor affects the turn-on and settling time for the output to ±0.5mA load. Figure 5 is the output response to a sourc- reach its final value. ing step from 4mA to 5mA, and Figure 6 is the output response of a sinking step from –4mA to –5mA. All LT1790 voltages perform virtually the same, so the LT1790-2.5 is used as an example. 3V VIN 3V VIN VOUT VOUT 2V 2V 1V 1V 0V 0V 1790 F01 1790 F02 Figure 1. Turn-On Characteristics of LT1790-2.5 Figure 2. Output Response to 0.5V Ripple on V IN VIN 4 LT1790-2.5 6 1k 3V C0.I1NµF C1µLF VGEN 1V 1, 2 1790 F03 Figure 3. Response Time Test Circuit VGEN 3V 2V VOUT VOUT (AC COUPLED) (AC COUPLED) VGEN –2V –3V 1790 F04 1790 F05 Figure 4. LT1790-2.5 Sourcing and Sinking 0.5mA Figure 5. LT1790-2.5 Sourcing 4mA to 5mA 1790fc 19 For more information www.linear.com/LT1790

LT1790 APPLICATIONS INFORMATION Positive or Negative Operation turning on and driving the grounded output. C1 provides stability during load transients. This connection maintains Series operation is ideal for extending battery life. If an nearly the same accuracy and temperature coefficient of LT1790 is operated in series mode it does not require an the positive connected LT1790. external current setting resistor. The specifications guar- antee that the LT1790 family operates to 18V. When the Long-Term Drift circuitry being regulated does not demand current, the series connected LT1790 consumes only a few hundred Long-term drift cannot be extrapolated from accelerated µW, yet the same connection can sink or source 5mA of high temperature testing. This erroneous technique load current when demanded. A typical series connection gives drift numbers that are widely optimistic. The only is shown on the front page of this data sheet. way long-term drift can be determined is to measure it over the time interval of interest. The LT1790S6 drift The circuit in Figure 7 shows the connection for a –2.5V data was taken on over 100 parts that were soldered into reference, although any LT1790 voltage option can be PC boards similar to a real world application. The boards configured this way to make a negative reference. The were then placed into a constant temperature oven with LT1790 can be used as very stable negative references, T = 30°C, their outputs scanned regularly and measured however, they require a positive voltage applied to Pin 4 A with an 8.5 digit DVM. Long-term drift curves are shown to bias internal circuitry. This voltage must be current in the Typical Performance Characteristics section. limited with R1 to keep the output PNP transistor from VGEN 8V R1 10k 3V 6V 4 6 C1 LT1790-2.5 VOUT 0.1µF 4V (AC COUPLED) 1, 2 VOUT = –2.5V 2V RL =VE1E 2–5 VµAOUT C1µLF 0V VEE 1790 F07 1790 F06 Figure 6. LT1790-2.5 Sinking –4mA to –5mA Figure 7. Using the LT1790-2.5 to Build a –2.5V Reference 1790fc 20 For more information www.linear.com/LT1790

LT1790 APPLICATIONS INFORMATION Hysteresis For lead-free solder, IR reflow temperatures are much higher, often 240°C to 260°C at the peak. As a result, Hysteresis data shown in Figures 8 and 9 represent the the packaging materials have been optimized to reduce worst-case data taken on parts from 0°C to 70°C and from V shift as possible during high temperature reflow. –40°C to 85°C. Units were cycled several times over these OUT In addition, care should be taken when using lead-free temperature ranges and the largest change is shown. As solder to minimize the peak temperature and dwell time expected, the parts cycled over the higher temperature as much as is practical. A typical lead-free reflow profile range have higher hysteresis than those cycled over the is shown in Figure 10. LT1790 units were heated using a lower range. similar profile, with a peak temperature of 250°C. These In addition to thermal hysteresis, the thermal shock parts were run through the heating process 3 times to associated with high temperature soldering may cause the show the cumulative effect of these heat cycles. Figure output to shift. For traditional PbSn solder temperatures, the output shift of the LT1790 is typically just 150ppm 300 (0.015%). 380s TP = 260° RAMP TL = 217°C DOWN 30 225 TS(MAX) = 200°C 25 EES (C) 150 T = T1 5=0 1°C90°C 13tP0s R UNITS 20 0°C TO 25°C DEG RAMP TO 13tL0s F 70°C TO 25°C 150°C R O 15 75 40s E B M 120s NU 10 0 0 2 4 6 8 10 5 MINUTES 1790 F10 0 –60 –50 –40 –30 –20 –10 0 10 20 30 40 50 60 Figure 10. Lead-Free Reflow Profile DISTRIBUTION (ppm) 1790 F08 Figure 8. Worst-Case 0°C to 70°C Hysteresis on 79 Units 9 8 50 7 45 TS 6 40 UNI F 5 UNITS 3305 MBER O 4 R OF 25 NU 3 E 80°C TO 25°C MB 20 2 U –40°C TO 25°C N 15 1 10 0 0 10 20 30 40 50 5 PPM 0 –100 –80 –60 –40 –20 0 20 40 60 80 100 1790 F11 DISTRIBUTION (ppm) Figure 11. 1X IR Reflow Peak Temperature = 250°C, Delta Output Voltage (ppm) 1790 F09 Figure 9. Worst-Case –40°C to 85°C Hysteresis on 80 Units 1790fc 21 For more information www.linear.com/LT1790

LT1790 APPLICATIONS INFORMATION 11 shows the shift after 1 cycle, while Figure 12 shows Assuming 80µA max supply current for the LT1790, a 25µA shift after 3 cycles. In the worst case, shifts are typically load, 120mV max dropout and a 4V to 30V input specifica- 150ppm, but may be as high as 290ppm. Shifts in output tion, the largest that R1 can be is (4V – 3.3V – 120mV)/ voltage are proportional to temperature and dwell time. (80µA + 25µA) = 5.5k. Furthermore, assuming 220mW of dissipation in the 18V SOT-23 Zener, this gives a max cur- In general, the output shift can be reduced or fully recovered rent of (220mW)/(18V) = 12.2mA. So the smallest that R1 by a long (12-24 hour) bake of the completed PC Board should be is (30V – 18V)/12.2mA = 1k, rated at 150mW. assembly at high temperature (100°C to 150C°) after soldering to remove mechanical stress that has been With R1 = 1k, and assuming a 450mV worst-case drop- induced by thermal shock. Once the PC Boards have cooled out, the LT1790 can deliver a minimum current of (4V to room temperature, they may continue to shift for up to – 3.3V–450mV)/(1k) = 250µA. In Figure 13, R1 and C1 3 times the bake time. This should be taken into account provide filtering of the Zener noise when the Zener is in before any calibration is performed. its noisy V-I knee. There are other variations for higher voltage operation that 3.5 use a pass transistor shown in Figures 14 and 15. These 3.0 circuits allow the input voltage to be as high as 160V while 2.5 maintaining low supply current. S T NI F U 2.0 O R BE 1.5 M NU 1.0 R1 R2 6VVS TO 160V 330k 4.7k ON SEMI 0.5 MMBT5551 BZX84C12 0 70 90 110 130 150 170 190 210 230 250 270 290 C1 PPM 0.1µF LT1790 VOUT C2 1790 F12 1µF Figure 12. 3X IR Reflow Peak Temperature = 250°C, 1790 F14 Delta Output Voltage (ppm) Higher Input Voltage Figure 14. Extended Supply Range Reference The circuit in Figure 13 shows an easy way to increase the input voltage range of the LT1790. The Zener diode can be anywhere from 6V to 18V. For equal power shar- VS C1 6.5V TO 160V ing between R1 and the Zener (at 30V), the 18V option R1 0.1µF 330k is better. The circuit can tolerate much higher voltages ON SEMI MMBT5551 for short periods and is suitable for transient protection. BAV99 4V TO 30V LT1790 VOUT C2 R1 1µF LT1790-3.3 VOUT 1790 F15 BZX84C18 C1 1µF Figure 15. Extended Supply Range Reference 0.1µF 1790 F13 Figure 13. Extended Supply Range Reference 1790fc 22 For more information www.linear.com/LT1790

LT1790 APPLICATIONS INFORMATION More Output Current bandwidth is √990 = 31.4. The total noise 10Hz to 1kHz noise is (450nV)(31.4) = 14.1µV. This agrees well with The circuit in Figure 16 is a compact, high output current, the measured noise. low dropout precision supply. The circuit uses the SOT-23 LT1782 and the ThinSOT LT1790. Resistive divider R1 and This estimate may not be as good with higher voltage R2 set a voltage 22mV below V . For under 1mA of output options, there are several reasons for this. Higher voltage S current, the LT1790 supplies the load. Above 1mA of load options have higher noise and they have higher variability current, the (+) input of the LT1782 is pulled below the due to process variations. 10Hz to 1kHz noise may vary by 22mV divider reference and the output FET turns on to 2dB on the LT1790-5 and 1dB on the LT1790-2.5. supply the load current. Capacitor C1 stops oscillations in Measured noise may also vary because of peaking in the the transition region. The no load standing current is only noise spectrum. This effect can be seen in the range of 120µA, yet the output can deliver over 300mA. 1kHz to 10kHz with all voltage options sourcing different load currents. From the Typical Performance curves the Noise 10Hz to 1kHz noise spectrum of the LT1790-5 is shown An estimate of the total integrated noise from 10Hz to 1kHz to be 3µV/√Hz at low frequency. The estimated noise is can be made by multiplying the flat band spot noise by (3µV)(31.4) = 93.4µV. The actual integrated 10Hz to 1kHz √BW. For example, from the Typical Performance curves, noise measures 118.3µV. The peaking shown causes this the LT1790-1.25 noise spectrum shows the average spot larger number. Peaking is a function of output capacitor noise to be about 450nV/√Hz. The square root of the as well as load current and process variations. VS 2.8V TO 3.3V NO LOAD SUPPLY CURRENT R3 120µA 22Ω R4 R1 5% + 1k 5% 680Ω VISHAY SILICONIX 5% LT1782 Si3445DV – C1 R2 0.1µF 100k 5% LT1790-2.5 VOUT = 2.5V C2 17909 F16ILOAD = 0mA to 300mA 1µF NOTE: NOT CURRENT LIMITED Figure 16. Compact, High Output Current, Low Dropout, Precision 2.5V Supply 1790fc 23 For more information www.linear.com/LT1790

LT1790 SIMPLIFIED SCHEMATIC 4 VIN 6 VOUT 1, 2 GND 1790 SS PACKAGE DESCRIPTION Please refer to http://www.linear.com/product/LT1790#packaging for the most recent package drawings. S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636) 2.90 BSC 0.62 0.95 (NOTE 4) MAX REF 1.22 REF 3.85 MAX 2.62 REF 1.4 MIN 2.80 BSC 1(.5N0O T–E 1 4.7)5 PIN ONE ID RECOMMENDED SOLDER PAD LAYOUT 0.30 – 0.45 0.95 BSC PER IPC CALCULATOR 6 PLCS (NOTE 3) 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 1.90 BSC 0.09 – 0.20 (NOTE 3) S6 TSOT-23 0302 NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 1790fc 24 For more information www.linear.com/LT1790

LT1790 REVISION HISTORY (Revision history begins at Rev C) REV DATE DESCRIPTION PAGE NUMBER C 09/16 Frequency Values on Output Impedance vs Frequency graph for 2.048V Typical Performance Characteristics 13 corrected. Package Description updated. 24 Revision History added. 25 Web links added. ALL 1790fc Information furnished by Linear Technology Corporation is believed to be accurate and reliable. 25 However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconneFctoiorn m ofo itrse c iinrcfuoirtsm aas tdioesnc rwibwedw h.elirneiena wr.icll onmot /inLfTri1ng7e9 o0n existing patent rights.

LT1790 TYPICAL APPLICATION –2.5V Negative 50mA Series Reference No Load Supply Current I = 1.6mA CC I = 440µA EE VCC = 5V 2k 4 6 LT1790-2.5 VZ = 5.1V 1, 2 5.1k –2.5V VEE = –5V 50mA MPS2907A 1µF 1790 TA03 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1019 Precision Reference Low Noise Bandgap, 0.05%, 5ppm/°C LTC®1798 Micropower Low Dropout Reference 0.15% Max, 6.5µA Supply Current LT1460 Micropower Precision Series Reference Bandgap, 130µA Supply Current, 10ppm/°C, Available in SOT-23 LT1461 Micropower Precision Low Dropout Reference Bandgap 0.04%, 3ppm/°C, 50µA Max Supply Current 1790fc 26 Linear Technology Corporation LT 0916 REV C • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 For more information www.linear.com/LT1790 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LT1790  LINEAR TECHNOLOGY CORPORATION 2000