LTM8027 60V, 4A DC/DC µModule Regulator FEATURES DESCRIPTION n Complete Switch Mode Power Supply The LTM®8027 is a complete 4A, DC/DC step-down power n Wide Input Voltage Range: 4.5V to 60V supply. Included in the package are the switching control- (7.5V Minimum Voltage to Start) ler, power switches, inductor and all support components. n Wide Output Voltage Range: 2.5V to 24V Operating over an input voltage range of 4.5V to 60V (7.5V (See Table 2) minimum voltage to start), the LTM8027 supports output n 4A Output Current voltages up to 24V, and a switching frequency range of n Programmable Soft-Start 100kHz to 500kHz, each set by a single resistor. Only n 9µA Shutdown Supply Current the bulk input and output filter capacitors are needed to n Selectable Switching Frequency Current Mode finish the design. Control The low profile package (4.32mm) enables utilization of n Up to 95% Efficiency unused space on the bottom of PC boards for high den- n SnPb (BGA) or RoHS Compliant (LGA and BGA) sity point of load regulation. A built-in soft-start timer is Finish adjustable with a small capacitor. n Surface Mount LGA (15mm × 15mm × 4.32mm) and (15mm × 15mm × 4.92mm) BGA Packages The LTM8027 is packaged in a compact (15mm × 15mm × 4.32mm) over-molded land grid array (LGA) and (15mm × 15mm × 4.92mm) BGA package suitable for automated APPLICATIONS assembly by standard surface mount equipment. The n 12V and 42V Automotive and Heavy Equipment LTM8027 is available with SnPb (BGA) or RoHS compli- n 48V Telecom Power Supplies ant terminal finish. n Avionics and Industrial Control Systems L, LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Distributed Power Converters TYPICAL APPLICATION 48W, 16V to 60V DC/DC µModule® Regulator Efficiency vs Load IN IN 16V TO 6V0IVN 4.7µF VIN VOUT 14V2AOVUT 10900 24VIN ×2 1M LTM8027 80 RUN BIAS1 70 SS BIAS2 %) SYNC AUX 2×24µF CY ( 60 N 50 RT ADJ E CI 48.7k GND 56.2k FFI 40 E 30 20 3845 TA01a 10 0 0 1 2 3 4 LOAD (A) 8027 TA01b 8027fd 1 For more information www.linear.com/LTM8027

LTM8027 ABSOLUTE MAXIMUM RATINGS (Note 1) V Voltage ................................................................65V Current Out of AUX .............................................200mA IN BIAS1 ........................................................................15V Internal Operating Temperature (Note 3) BIAS2 ........................................................................24V E-, I-Grade .........................................–40°C to 125°C SYNC, ADJ, R , RUN, SS Voltages ..............................5V MP-Grade ..........................................–55°C to 125°C T Current into RUN Pin (Note 2) ..................................1mA Peak Solder Reflow Body Temperature .................245°C V , AUX .................................................................25V Storage Temperature Range ..................–55°C to 125°C OUT PIN CONFIGURATION TOP VIEW TOP VIEW 11 11 10 VOUT 10 VOUT BANK 1 BANK 1 9 9 8 8 AUX 7 GND AUX 7 GND BIAS1 6 BANK 2 BIAS1 6 BANK 2 SS 5 SS 5 RUN 4 RUN 4 BIAS2 3 BIAS2 3 ADJ 2 VBIANNK 3 ADJ 2 VBIANNK 3 1 1 A B C D E F G H J K L A B C D E F G H J K L RT SYNC RT SYNC LGA PACKAGE BGA PACKAGE 113-LEAD (15mm × 15mm × 4.32mm) 113-LEAD (15mm × 15mm × 4.92mm) TJMAX = 125°C, θJA = 12.2°C/W, θJC(TOP) = 9.3°C/W, TJMAX = 125°C, θJA = 12.2°C/W, θJC(TOP) = 9.3°C/W, θJC(BOTTOM) = 3.6°C/W, θJBOARD = 7.54°C/W θJC(BOTTOM) = 3.6°C/W, θJBOARD = 7.54°C/W θ VALUES DETERMINED PER JESD 51-9 θ VALUES DETERMINED PER JESD 51-9 WEIGHT = 2.6 GRAMS WEIGHT = 2.6 GRAMS ORDER INFORMATION http://www.linear.com/product/LTM8027#orderinfo PART NUMBER PAD OR BALL FINISH PART MARKING* PACKAGE MSL TEMPERATURE RANGE TYPE RATING (See Note 3) DEVICE FINISH CODE LTM8027EV#PBF Au (RoHS) LTM8027V e4 LGA 3 –40°C to 125°C LTM8027IV#PBF Au (RoHS) LTM8027V e4 LGA 3 –40°C to 125°C LTM8027MPV#PBF Au (RoHS) LTM8027V e4 LGA 3 –55°C to 125°C LTM8027EY#PBF SAC305 (RoHS) LTM8027Y e1 BGA 3 –40°C to 125°C LTM8027IY#PBF SAC305 (RoHS) LTM8027Y e1 BGA 3 –40°C to 125°C LTM8027IY SnPb (63/37) LTM8027Y e0 BGA 3 –40°C to 125°C LTM8027MPY#PBF SAC305 (RoHS) LTM8027Y e1 BGA 3 –55°C to 125°C LTM8027MPY SnPb (63/37) LTM8027Y e0 BGA 3 –55°C to 125°C Consult Marketing for parts specified with wider operating temperature • Recommended LGA and BGA PCB Assembly and Manufacturing ranges. *Device temperature grade is indicated by a label on the shipping Procedures: container. Pad or ball finish code is per IPC/JEDEC J-STD-609. www.linear.com/umodule/pcbassembly • Pb-free and Non-Pb-free Part Markings: • LGA and BGA Package and Tray Drawings: www.linear.com/leadfree www.linear.com/packaging 8027fd 2 For more information www.linear.com/LTM8027

LTM8027 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full internal operating temperature range, otherwise specifications are at T = 25°C. V = 20V, BIAS1 = BIAS2 = 10V, RUN = 2V, unless otherwise noted. A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Input DC Voltage (Note 5) l 4.5 60 V IN V Maximum Output DC Voltage 0A < I ≤ 4A, V = 48V 24 V OUT OUT IN I Output DC Current V ≤ 60V, V = 12V, (Note 4) 0 4 A OUT IN OUT V Minimum Start Voltage 7.5 V IN(START) ∆VOUT/∆VIN Line Regulation VOUT = 12V, 15V< VIN < 60V, ILOAD = 4A 0.2 % ∆VOUT/∆ILOAD Load Regulation VOUT = 12V, VIN = 24V, 0A < ILOAD ≤ 4A 0.2 % V Input Undervoltage Lockout Threshold (Note 5) 4.6 V UVLO(RISING) (Rising) V Input Undervoltage Lockout Threshold (Note 5) 3.7 V UVLO(FALLING) (Falling) V ADJ Voltage 1.224 1.238 V ADJ l 1.215 1.245 V I Quiescent Current into IN V = V , V = 12VDC, No Load 39 mA Q(VIN) BIAS AUX OUT V = 0V 9 µA RUN V BIAS1 Undervoltage Lockout (Rising) 6.5 V BIAS1 BIAS1 Undervoltage Lockout (Falling) 6 V I Current into BIAS1 No Load 25 mA BIAS1 RUN = 0V 25 µA V Minimum BIAS2 Voltage 3 V BIAS2 I Current Into BIAS2 1 µA BIAS2 V Minimum Voltage to Overdrive Internal 8.5 V BIAS1(MINOV) Regulator (INTV ) CC R Internal Feedback Resistor 499 kΩ FB V RUN Enable Voltage (Rising) 1.4 V RUN(RISING) V RUN Enable Voltage (Falling) 1.2 V RUN(FALLING) f Switching Frequency R = 187kΩ 100 kHz SW T R = 23.7kΩ 500 kHz T R SYNC Input Resistance 40 kΩ SYNC V SYNC Voltage Threshold f = 350kHz l 2.3 V SYNC(TH) SYNC I Soft-Start Charging Current 2 µA SS Note 1: Stresses beyond those listed under Absolute Maximum Ratings –40°C to 125°C internal operating temperature range. The LTM8027MP may cause permanent damage to the device. Exposure to any Absolute is guaranteed to meet specifications over the full –55°C to 125°C Maximum Rating condition for extended periods may affect device internal operating range. Note that the maximum internal temperature is reliability and lifetime. determined by specific operating conditions in conjunction with board Note 2: The RUN pin is internally clamped to 5V. layout, the rated package thermal resistance and other environmental factors. Note 3: The LTM8027E is guaranteed to meet performance specifications from 0°C to 125°C internal operating temperature. Specifications over Note 4: The maximum continuous output current may be derated by the the full –40°C to 125°C internal operating temperature range are assured LTM8027 junction temperature. by design, characterization and correlation with statistical process Note 5: V voltages below the start-up threshold (7.5V) are only IN controls. The LTM8027I is guaranteed to meet specifications over the full supported when BIAS1 is externally driven above 6.5V. 8027fd 3 For more information www.linear.com/LTM8027

LTM8027 TYPICAL PERFORMANCE CHARACTERISTICS (T = 25°C unless otherwise noted) A Efficiency vs Load, V = 2.5V Efficiency vs Load, V = 3.3V Efficiency vs Load, V = 5V OUT OUT OUT 100 100 100 90 90 90 80 80 80 70 70 70 %) %) %) Y ( 60 Y ( 60 Y ( 60 C C C N 50 N 50 N 50 E E E EFFICI 40 EFFICI 40 5VIN EFFICI 40 30 30 12VIN 30 12VIN 20 51V2VININ 20 2346VVIINN 20 2346VVIINN 10 24VIN 10 48VIN 10 48VIN 36VIN 60VIN 60VIN 0 0 0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G01 8027 G02 8027 G03 Efficiency vs Load, V = 8V Efficiency vs Load, V = 12V Efficiency vs Load, V = 15V OUT OUT OUT 100 100 100 90 90 90 80 80 80 70 70 70 %) %) %) Y ( 60 Y ( 60 Y ( 60 C C C N 50 N 50 N 50 E E E CI CI CI FI 40 FI 40 FI 40 F F F E E E 30 12VIN 30 30 20 2346VVIINN 20 2346VVIINN 20 2346VVIINN 10 48VIN 10 48VIN 10 48VIN 60VIN 60VIN 60VIN 0 0 0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G04 8027 G05 8027 G06 Input Current Efficiency vs Load, V = 18V Efficiency vs Load, V = 24V vs V Output Shorted OUT OUT IN 100 100 1.2 90 90 1.0 80 80 NCY (%) 657000 NCY (%) 657000 RRENT (A) 00..68 E E U EFFICI 3400 EFFICI 3400 NPUT C 0.4 I 24VIN 20 36VIN 20 36VIN 0.2 10 48VIN 10 48VIN 60VIN 60VIN 0 0 0 0 1 2 3 4 0 1 2 3 4 0 10 20 30 40 50 60 70 LOAD (A) LOAD (A) INPUT VOLTAGE (V) 8027 G07 8027 G08 8027 G09 8027fd 4 For more information www.linear.com/LTM8027

LTM8027 TYPICAL PERFORMANCE CHARACTERISTICS (T = 25°C unless otherwise noted) A Input Current vs Load, Input Current vs Load, Input Current vs Load, V = 2.5V V = 3.3V V = 5V OUT OUT OUT 3000 3500 2000 5VIN 5VIN 12VIN 2500 1224VVIINN 3000 1224VVIINN 11680000 2346VVIINN 36VIN 36VIN 48VIN NT (mA)2000 NT (mA)22050000 4680VVIINN NT (mA)11240000 60VIN RRE1500 RRE RRE1000 NPUT CU1000 NPUT CU11050000 NPUT CU 680000 I I I 400 500 500 200 0 0 0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G10 8027 G11 8027 G12 Input Current vs Load, Input Current vs Load, Input Current vs Load, V = 8V V = 12V V = 15V OUT OUT OUT 3500 2500 3000 12VIN 24VIN 24VIN 3000 2346VVIINN 2000 3468VVIINN 2500 3468VVIINN mA)2500 4680VVIINN mA) 60VIN mA)2000 60VIN RRENT (2000 RRENT (1500 RRENT (1500 PUT CU1500 PUT CU1000 PUT CU1000 N1000 N N I I I 500 500 500 0 0 0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G13 8027 G14 8027 G15 Input Current vs Load, Input Current vs Load, Bias Current vs Load, V = 18V V = 24V V = 2.5V OUT OUT OUT 3500 3500 15.50 24VIN 36VIN 3000 3468VVIINN 3000 4680VVIINN 15.00 60VIN mA)2500 mA)2500 mA)14.50 NPUT CURRENT (112050000000 NPUT CURRENT (112050000000 BIAS CURRENT (111433...050000 I I 36VIN 500 500 12.50 24VIN 12VIN 0 0 12.00 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G16 8027 G17 8027 G18 8027fd 5 For more information www.linear.com/LTM8027

LTM8027 TYPICAL PERFORMANCE CHARACTERISTICS (T = 25°C unless otherwise noted) A Bias Current vs Load, Bias Current vs Load, Bias Current vs Load, V = 3.3V V = 5V V = 8V OUT OUT OUT 18.0 16.0 26.0 17.5 25.5 15.5 17.0 25.0 A) A) A) m m 15.0 m T (16.5 T ( T (24.5 N N N RRE16.0 RRE 14.5 RRE24.0 U U U S C15.5 S C S C23.5 BIA BIA 14.0 BIA 15.0 48VIN 48VIN 23.0 36VIN 13.5 36VIN 48VIN 14.5 24VIN 24VIN 22.5 36VIN 12VIN 12VIN 24VIN 14.0 13.0 22.0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G19 8027 G20 8027 G21 Bias Current vs Load, Bias Current vs Load, Bias Current vs Load, V = 12V V = 15V V = 18V OUT OUT OUT 29.5 38 45 29.0 37 44 43 28.5 36 mA)28.0 mA) mA) 42 BIAS CURRENT (222767...550 BIAS CURRENT ( 333543 BIAS CURRENT ( 43341890 32 26.0 48VIN 48VIN 37 25.5 36VIN 31 36VIN 36 48VIN 24VIN 24VIN 36VIN 25.0 30 35 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G22 8027 G23 8027 G24 Bias Current vs Load, Minimum V vs Load, Minimum V vs Load, IN IN V = 24V V = 5V V = 8V OUT OUT OUT 46 6.0 10.0 5.9 9.8 44 5.8 9.6 A) 42 5.7 9.4 m T ( 5.6 9.2 EN 40 V) V) RR (N5.5 (N9.0 S CU 38 VI5.4 VI8.8 A BI 36 5.3 8.6 5.2 8.4 34 48VIN 5.1 8.2 36VIN 32 5.0 8.0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G25 8027 G26 8027 G27 8027fd 6 For more information www.linear.com/LTM8027

LTM8027 TYPICAL PERFORMANCE CHARACTERISTICS (T = 25°C unless otherwise noted) A Minimum V vs Load, Minimum V vs Load, Minimum V vs Load, IN IN IN V = 12V V = 15V V = 18V OUT OUT OUT 16.0 19.0 24 15.5 18.5 23 15.0 18.0 22 14.5 17.5 V (V)IN14.0 V (V)IN17.0 V (V)IN 21 13.5 16.5 20 13.0 16.0 19 12.5 15.5 12.0 15.0 18 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G28 8027 G29 8027 G30 Minimum V vs Load, Minimum V vs V , Minimum V vs Load, IN IN OUT IN V = 24V I = 4A V = –3.3V OUT OUT OUT 32 35 9 8 30 30 7 28 25 6 V) 26 V) 20 V) 5 (N (N (N VI 24 VI 15 VI 4 3 22 10 2 20 5 1 18 0 0 0 1 2 3 4 0 5 10 15 20 25 0 1 2 3 4 LOAD (A) VOUT (V) LOAD (A) 8027 G31 8027 G32 8027 G33 Minimum V vs Load, Minimum V vs Load, Minimum V vs Load, IN IN IN V = –5V V = –8V V = –12V OUT OUT OUT 12 30 50 45 10 25 40 35 8 20 30 V) V) V) V (IN 6 V (IN 15 V (IN 25 20 4 10 15 10 2 5 5 0 0 0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G34 8027 G35 8027 G36 8027fd 7 For more information www.linear.com/LTM8027

LTM8027 TYPICAL PERFORMANCE CHARACTERISTICS (T = 25°C unless otherwise noted) A Temperature Rise vs Load, Temperature Rise vs Load, Temperature Rise vs Load, V = 2.5V V = 3.3V V = 5V OUT OUT OUT 42 45 50 37 3264VVIINN 40 6408VVIINN 45 6408VVIINN 12VIN 36VIN 40 36VIN RISE (°C) 2372 5VIN RISE (°C) 3305 21542VVVINIINN RISE (°C) 3305 2142VVIINN URE 22 URE 25 URE 25 MPERAT 17 MPERAT 2105 MPERAT 1250 TE 12 TE 10 TE 10 7 5 5 2 0 0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G37 8027 G38 8027 G39 Temperature Rise vs Load, Temperature Rise vs Load, Temperature Rise vs Load, V = 8V V = 12V V = 15V OUT OUT OUT 70 80 90 60VIN 60VIN 60VIN 60 48VIN 70 48VIN 80 48VIN 36VIN 36VIN 36VIN C) 24VIN C) 60 24VIN C) 70 24VIN E (° 50 12VIN E (° 16VIN E (° 60 20.5VIN E RIS 40 E RIS 50 E RIS 50 R R R U U 40 U AT 30 AT AT 40 R R R E E 30 E MP 20 MP MP 30 TE TE 20 TE 20 10 10 10 0 0 0 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) LOAD (A) 8027 G40 8027 G41 8027 G42 Temperature Rise vs Load, Temperature Rise vs Load, V = 18V V = 24V OUT OUT 100 100 90 6408VVIINN 90 6408VVIINN 80 36VIN 80 36VIN C) 26VIN C) E (° 70 E (° 70 S S RI 60 RI 60 E E R 50 R 50 U U T T RA 40 RA 40 E E P P M 30 M 30 E E T T 20 20 10 10 0 0 0 1 2 3 4 0 1 2 3 4 LOAD (A) LOAD (A) 8027 G43 8027 G44 8027fd 8 For more information www.linear.com/LTM8027

LTM8027 PIN FUNCTIONS GND (Bank 2): Tie these GND pins to a local ground plane PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE below the LTM8027 and the circuit components. LAYOUT CAREFULLY. RT (Pin B1): The RT pin is used to program the switching V (Bank 3): The V pins supply current to the LTM8027’s frequency of the LTM8027 by connecting a resistor from IN IN internal regulator and to the internal power switch. These this pin to ground. The Applications Information section of pins must be locally bypassed with an external, low ESR the data sheet includes a table to determine the resistance capacitor (see Table 2). value based on the desired switching frequency. Minimize capacitance at this pin. V (Bank 1): Power Output Pins. Apply the output OUT filter capacitor and the output load between these and SYNC (Pin C1): The SYNC pin provides an external clock the GND pins. input for synchronization of the internal oscillator. The R resistor should be set such that the internal oscillator AUX (Pin A7): Low Current Voltage Source for BIAS1 T frequency is 10% to 25% below the external clock fre- and BIAS2. In many designs, the BIAS pin is connected quency. This external clock frequency must be between to V by way of the AUX pin. The AUX pin is internally OUT 100kHz and 500kHz. If unused, tie the SYNC pin to GND. connected to V and is placed near the BIAS pins to ease OUT For more information see Oscillator Sync in the Application printed circuit board routing. Although this pin is internally Information section of this data sheet. connected to V , do NOT connect this pin to the load. If OUT this pin is not tied to BIAS1 and BIAS2, leave it floating. ADJ (Pin A2): The LTM8027 regulates its ADJ pin to 1.23V. Connect the adjust resistor from this pin to ground. The BIAS1 (Pin A6): The BIAS1 pin connects to the internal value of R is given by the equation: power bus. Connect to a power source greater than 8.5V. ADJ If the output is greater than 8.5V, connect it to this pin. If R = 613.77/(V – 1.23) ADJ OUT the output voltage is less, connect this to a voltage source where R is in kΩ. ADJ between 8.5V and 15V. SS (Pin A5): The soft-start pin is used to program the BIAS2 (Pin A3): Internal Biasing Power. Connect to AUX supply soft-start function. Use the following formula to (if 24V or less) or a voltage source above 3V. Do not leave calculate C for a given output voltage slew rate: SS BIAS2 floating. C = 2µA(t /1.231V) SS SS RUN (Pin A4): Tie the RUN pin to ground to shut down the LTM8027. Tie to 1.4V or more for normal operation. The pin should be left unconnected when not using the The RUN pin is internally clamped to 5V, so when it is soft-start function. pulled up, be sure to use a pull-up resistor that limits the current into the RUN pin to less than 1mA. If the shutdown feature is not used, tie this pin to the V pin through a IN pull-up resistor. 8027fd 9 For more information www.linear.com/LTM8027

LTM8027 BLOCK DIAGRAM VIN 6.8µH VOUT 499k 4.7pF 2.2µF RUN AUX INTERNAL SS CURRENT CONNECTION MODE TO VOUT CONTROLLER SYNC INTERNAL INTVCC BIAS1 VIN LINEAR REGULATOR BIAS2 GND RT ADJ 8027 BD OPERATION The LTM8027 is a standalone nonisolated step-down The LTM8027 is a fixed frequency PWM regulator. The switching DC/DC power supply with an input voltage range switching frequency is set by simply connecting the ap- of 4.5V to 60V that can deliver up to 4A of output current. propriate resistor from the RT pin to GND. This module provides a precisely regulated output volt- A linear regulator provides internal power (shown as age up to 24V, programmable via one external resistor. INTV on the Block Diagram) to the control circuitry. CC Given that the LTM8027 is a step-down converter, make The bias regulator normally draws power from the V IN sure that the input voltage is high enough to support the pin, but if the BIAS1 pin is connected to an external volt- desired output voltage and load current. A simplified block age higher than 8.5V, bias power will be drawn from the diagram is given above. The LTM8027 contains a current external source (typically the regulated output voltage). mode controller, power switching element, power induc- This improves efficiency. The RUN pin is used to enable tor, power MOSFETs and a modest amount of input and or place the LTM8027 in shutdown, disconnecting the output capacitance. output and reducing the input current to less than 9µA. 8027fd 10 For more information www.linear.com/LTM8027

LTM8027 APPLICATIONS INFORMATION For most applications, the design process is straight input voltage can ring to twice its nominal value, possi- forward, summarized as follows: bly exceeding the device’s rating. This situation is easily avoided; see the Hot-Plugging Safely section. 1. Look at Table 2 and find the row that has the desired input range and output voltage. Input Power Requirements 2. Apply the recommended C , C , R and R values. IN OUT ADJ T The LTM8027 is biased using an internal linear regulator 3. Connect the BIAS pins as indicated. to generate operational voltages from the V pin. Virtually IN all of the circuitry in the LTM8027 is biased via this internal While these component and connection combinations have linear regulator output (INTV on the Block Diagram). been tested for proper operation, it is incumbent upon the CC This pin is internally decoupled with a low ESR capacitor user to verify proper operation over the intended system’s to GND. The INTV regulator generates an 8V output line, load and environmental conditions. CC provided there is ample voltage on the V pin. The INTV IN CC regulator has approximately 1V of dropout, and will follow Capacitor Selection Considerations the V pin with voltages below the dropout threshold. IN The C and C capacitor values in Table 2 are the IN OUT The LTM8027 has a typical start-up requirement of V > minimum recommended values for the associated oper- IN 7.5V. This assures that the onboard regulator has ample ating conditions. Applying capacitor values below those headroom to bring the internal regulator (INTV ) above indicated in Table 2 is not recommended, and may result CC its UVLO threshold. The INTV regulator can only source in undesirable operation. Using larger values is generally CC current, so forcing the BIAS1 pin above 8.5V allows use acceptable, and can yield improved dynamic response, if of externally derived power for the IC. This effectively it is necessary. Again, it is incumbent upon the user to shuts down the internal linear regulator and reduces verify proper operation over the intended system’s line, power dissipation within the LTM8027. Using the onboard load and environmental conditions. regulator for start-up, then applying power to BIAS1 from Ceramic capacitors are small, robust and have very low the converter output or external supply maximizes con- ESR. However, not all ceramic capacitors are suitable. version efficiencies and is a common practice. If BIAS1 X5R and X7R types are stable over temperature and ap- is maintained above 6.5V using an external source, the plied voltage and give dependable service. Other types, LTM8027 can continue to operate with V as low as 4.5V. IN including Y5V and Z5U have very large temperature and voltage coefficients of capacitance. In an application cir- BIAS Power cuit they may have only a small fraction of their nominal The internal circuitry of the LTM8027 is powered by the capacitance resulting in much higher output voltage ripple INTV bus, which is derived either from the afore men- than expected. CC tioned internal linear regulator or the BIAS1 pin, if it is A final precaution regarding ceramic capacitors concerns greater than 8.5V. Since the internal linear regulator is the maximum input voltage rating of the LTM8027. A by nature dissipative, deriving INTV from an external CC ceramic input capacitor combined with trace or cable source through the BIAS pins reduces the power lost within inductance forms a high Q (under damped) tank circuit. the LTM8027 and can increase overall system efficiency. If the LTM8027 circuit is plugged into a live supply, the 8027fd 11 For more information www.linear.com/LTM8027

LTM8027 APPLICATIONS INFORMATION For example, suppose the LTM8027 needs to provide ing SS pin voltage, reducing the output voltage overshoot 5V from an input voltage source that is nominally 12V. during a short-circuit recovery. From Table 2, the recommended R value is 75k, which T The desired soft-start time (t ) is programmed via the SS corresponds to an operating frequency of 210kHz. From C capacitor as follows: SS the graphs in the Typical Performance Characteristics, the typical internal regulator (INTV ) current at 12V and 2µA(cid:127)t CC IN C = SS 210kHz is 15mA. The power dissipated by the internal SS 1.231V linear regulator at 12V is given by the equation: IN The amount of time in which the power supply must be P = (V – 8) • I INTVCC IN INTVCC under a V , internal regulator (INTV ) or V UVLO IN CC SHDN or only 60mW. This has a small but probably acceptable fault condition (tFAULT) before the SS pin voltage enters effect on the operating temperature of the LTM8027. its active region is approximated by the following formula: If the input rises to 60V, however, the power dissipation C (cid:127)0.65V t = SS is a lot higher, over 780mW. This can cause unnecessarily FAULT 50µA high junction temperatures if the INTV regulator must CC dissipate this amount of power for very long. Operating Frequency Trade-offs Connect BIAS2 to AUX (if 24V or less) or a voltage source The LTM8027 uses a constant frequency architecture that above 3V. can be programmed over a 100kHz to 500kHz range with a single resistor from the RT pin to ground. The nominal Soft-Start voltage on the RT pin is 1V and the current that flows from The soft-start function controls the slew rate of the power this pin is used to charge an internal oscillator capacitor. supply output voltage during start-up. A controlled output The value of R for a given operating frequency can be T voltage ramp minimizes output voltage overshoot, reduces chosen from Figure 1 or Table 1. inrush current from the V supply, and facilitates supply IN sequencing. A capacitor connected from the SS pin to GND 600 programs the slew rate. The capacitor is charged from an internal 2µA current source producing a ramped voltage 500 that overrides the command reference to the controller, resulting in a smooth output voltage ramp. The soft-start kHz)400 Y ( circuit is disabled once the SS pin voltage has been charged NC300 E U to 200mV above the internal reference of 1.231V. Q E R200 F During a V UVLO, RUN event, or undervoltage on internal IN bias, the SS pin voltage is discharged with a 50µA current. 100 Therefore, the value of the SS capacitor determines how 0 long one of these events must be in order to completely 0 50 100 150 200 RT (kΩ) discharge the soft-start capacitor. In the case of an output 8027 F01 overload or short circuit, the SS pin voltage is clamped to Figure 1. Timing Resistor (R ) Value T a diode drop above the ADJ pin. Once the short has been removed the V pin voltage starts to recover. The soft- ADJ start circuit takes control of the output voltage slew rate once the V pin voltage has exceeded the slowly ramp- ADJ 8027fd 12 For more information www.linear.com/LTM8027

LTM8027 APPLICATIONS INFORMATION Table 1 lists typical resistor values for common operating RUN Control frequencies. The LTM8027 RUN pin uses a reference threshold of 1.4V. Table 1. R Resistor Values vs Frequency This precision threshold allows use of the RUN pin for both T logic-level controlled applications and analog monitoring ap- R (kΩ) f (kHz) T SW plications such as power supply sequencing. The LTM8027 187 100 operational status is primarily controlled by a UVLO circuit 118 150 on internal power source. When the LTM8027 is enabled 82.5 200 via the RUN pin, only the internal regulator (INTV ) is en- 63.4k 250 CC abled. Switching remains disabled until the UVLO threshold 48.7k 300 is achieved at the BIAS1 pin, when the remainder of the 40.2k 350 LTM8027 is enabled and switching commences. 31.6k 400 27.4k 450 Because the LTM8027 high power converter is a power 23.7k 500 transfer device, a voltage that is lower than expected on the input supply could require currents that exceed the It is recommended that the user apply the RT value given sourcing capabilities of that supply, causing the system in Table 2 for the input and output operating condition. to lock up in an undervoltage state. Input supply start- System level or other considerations, however, may neces- up protection can be achieved by enabling the RUN pin sitate another operating frequency. While the LTM8027 is using a resistive divider from the V supply to ground. IN flexible enough to accommodate a wide range of operat- Setting the divider output to 1.4V when that supply is at ing frequencies, a haphazardly chosen one may result an adequate voltage prevents an LTM8027 converter from in undesirable operation under certain operating or fault drawing large currents until the input supply is able to conditions. A frequency that is too high can damage the provide the required power. 200mV of input hysteresis on LTM8027 if the output is overloaded or short-circuited. A the RUN pin allows for about 15% of input supply droop frequency that is too low can result in a final design that has before disabling the converter. too much output ripple or too large of an output capacitor. Input UVLO and RUN The maximum frequency (f ) at which the LTM8027 MAX should be allowed to switch and the minimum frequency The RUN pin has a precision voltage threshold with hys- set resistor value that should be used for a given set of teresis which can be used as an undervoltage lockout input and output operating condition is given in Table 2 threshold (UVLO) for the power supply. Undervoltage as R . There are additional conditions that must be lockout keeps the LTM8027 in shutdown until the supply T(MIN) satisfied if the synchronization function is used. Please input voltage is above a certain voltage programmed by refer to the Synchronization section for details. the user. The hysteresis voltage prevents noise from falsely tripping UVLO. Resistors are chosen by first selecting R B Output Voltage Programming (refer to Figure 2). Then: The LTM8027 regulates its ADJ pin to 1.23V. Connect the ⎛ V ⎞ IN(ON) adjust resistor from this pin to ground. The value of R R =R (cid:127) –1 ADJ A B ⎜ ⎟ ⎝ 1.4V ⎠ is given by the equation RADJ = 613.77/(VOUT – 1.23), where R is in kΩ. ADJ where V is the input voltage at which the undervolt- IN(ON) age lockout is disabled and the supply turns on. 8027fd 13 For more information www.linear.com/LTM8027

LTM8027 APPLICATIONS INFORMATION VSUPPLY complete discussion). The low loss ceramic capacitor combined with stray inductance in series with the power RA source forms an under damped tank circuit, and the volt- RUN PIN age at the V pin of the LTM8027 can ring to twice the IN RB nominal input voltage, possibly exceeding the LTM8027’s rating and damaging the part. If the input supply is poorly 8027 F02 controlled or the user will be plugging the LTM8027 into an Figure 2. Undervoltage Lockout Resistive Divider energized supply, the input network should be designed to prevent this overshoot by introducing a damping element Example: Select RB = 49.9k, VIN(ON) = 14.5V (based upon into the path of current flow. This is often done by add- a 15V minimum input voltage) ing an inexpensive electrolytic bulk capacitor across the input terminals of the LTM8027. The criteria for selecting ⎛14.5V ⎞ R =49.9k(cid:127) –1 = 464k(cid:31) this capacitor is that the ESR is high enough to damp the A ⎜ ⎟ ⎝ 1.4V ⎠ ringing, and the capacitance value is several times larger than the LTM8027 ceramic input capacitor. The bulk The V turn off voltage is 15% below turn on. In the IN capacitor does not need to be located physically close to example the V would be 12.3V. The shutdown func- IN(OFF) the LTM8027; it should be located close to the application tion can be disabled by connecting the RUN pin to the V IN board’s input connector instead. pin through a large value pull-up resistor, (R ). This pin PU contains a low impedance clamp at 6V, so the RUN pin Synchronization will sink current from the R pull-up resistor: PU The oscillator can be synchronized to an external clock. V –6V I = IN Choose the RT resistor such that the resultant frequency is RUN R at least 10% below the desired synchronization frequency. PU It is recommended that the SYNC pin be driven with a Because this arrangement will clamp the RUN pin to square wave that has amplitude greater than 2.3V, pulse 6V, it will violate the 5V absolute maximum voltage width greater than 1µs and rise time less than 500ns. The rating of the pin. This is permitted, however, as long rising edge of the sync wave form triggers the discharge as the absolute maximum input current rating of 1mA of the internal oscillator capacitor. is not exceeded. Input RUN pin currents of <100µA are recommended: a 1M or greater pull-up resistor is PCB Layout typically used for this configuration. Most of the headaches associated with PCB layout have been alleviated or even eliminated by the high level of Hot-Plugging Safely integration of the LTM8027. The LTM8027 is neverthe- The small size, robustness and low impedance of ceramic less a switching power supply, and care must be taken to capacitors make them an attractive option for the input minimize EMI and ensure proper operation. Even with the bypass capacitor of LTM8027. However, these capacitors high level of integration, you may fail to achieve specified can cause problems if the LTM8027 is plugged into a live operation with a haphazard or poor layout. See Figure 3 supply (see Linear Technology Application Note 88 for a for a suggested layout. 8027fd 14 For more information www.linear.com/LTM8027

LTM8027 APPLICATIONS INFORMATION VOUT COUT COUT GND AUX BIAS1 SS RUN BIAS2 CIN VIN RADJ RT GND SYNC 8027 F03 Figure 3. Suggested Layout Ensure that the grounding and heat sinking are acceptable. Figure 3. The LTM8027 can benefit from the heat sinking A few rules to keep in mind are: afforded by vias that connect to internal GND planes at these locations, due to their proximity to internal power 1. Place the R and R resistors as close as possible to ADJ T handling components. The optimum number of thermal their respective pins. vias depends upon the printed circuit board design. 2. Place the C capacitor as close as possible to the V For example, a board might use very small via holes. IN IN and GND connection of the LTM8027. It should employ more thermal vias than a board that uses larger holes. 3. Place the C capacitor as close as possible to the OUT V and GND connection of the LTM8027. OUT Thermal Considerations 4. Place the C and C capacitors such that their IN OUT The LTM8027 output current may need to be derated if ground current flow directly adjacent to or underneath it is required to operate in a high ambient temperature or the LTM8027. deliver a large amount of continuous power. The amount 5. Connect all of the GND connections to as large a copper of current derating is dependent upon the input voltage, pour or plane area as possible on the top layer. Avoid output power and ambient temperature. The temperature breaking the ground connection between the external rise curves given in the Typical Performance Character- components and the LTM8027. istics section can be used as a guide. These curves were generated by a LTM8027 mounted to a 58cm2 4-layer FR4 Use vias to connect the GND copper area to the board’s printed circuit board. Boards of other sizes and layer count internal ground planes. Liberally distribute these GND vias can exhibit different thermal behavior, so it is incumbent to provide both a good ground connection and thermal upon the user to verify proper operation over the intended path to the internal planes of the printed circuit board. Pay system’s line, load and environmental operating conditions. attention to the location and density of the thermal vias in 8027fd 15 For more information www.linear.com/LTM8027

LTM8027 APPLICATIONS INFORMATION The junction-to-air and junction-to-board thermal resis- The die temperature of the LTM8027 must be lower than tances given in the Pin Configuration diagram may also the maximum rating of 125°C, so care should be taken be used to estimate the LTM8027 internal temperature. in the layout of the circuit to ensure good heat sinking These thermal coefficients are determined per JESD 51-9 of the LTM8027. The bulk of the heat flow out of the (JEDEC standard, test boards for area array surface mount LTM8027 is through the bottom of the module and the package thermal measurements) through analysis and LGA pads into the printed circuit board. Consequently a physical correlation. Bear in mind that the actual thermal poor printed circuit board design can cause excessive resistance of the LTM8027 to the printed circuit board heating, resulting in impaired performance or reliability. depends upon the design of the circuit board. Please refer to the PCB Layout section for printed circuit board design suggestions. Table 2. Recommended Component Values and Configuration (T = 25°C. See Typical Performance Characteristics for load Conditions) A V RANGE V R f R f R IN OUT ADJ OPTIMAL OPTIMAL MAX MAX (V) (V) C C BIAS1 (kΩ) (kHz) (kΩ) (kHz) (kΩ) IN OUT 4.5 to 60 3.3 2 × 4.7µF 2220 100V 5 × 100µF 1812 6.3V 8.5V to 15V 301 115 154 160 107 7.5 to 60 5 2 × 4.7µF 2220 100V 4 × 100µF 1210 6.3V 8.5V to 15V 162 210 75.0 230 68.2 10.5 to 60 8 2 × 4.7µF 2220 100V 4 × 47µF 1210 10V 8.5V to 15V 90.9 260 59.0 350 40.2 16 to 60 12 2 × 4.7µF 2220 100V 4 × 22µF 1210 16V AUX 56.2 300 48.7 500 23.7 20.5 to 60 15 2 × 4.7µF 2220 100V 4 × 22µF 1210 16V AUX 44.2 350 40.2 500 23.7 26 to 60 18 2 × 4.7µF 2220 100V 4 × 10µF 1812 25V 8.5V to 15V 36.5 400 31.6 500 23.7 34 to 60 24 2 × 4.7µF 2220 100V 4 × 10µF 1812 25V 8.5V to 15V 26.7 430 28.7 500 23.7 4.5 to 40 2.5 2 × 10µF 2220 50V 5 × 100µF 1812 6.3V 8.5V to 15V 487 145 124 185 88.7 4.5 to 40 3.3 2 × 10µF 2220 50V 4 × 100µF 1812 6.3V 8.5V to 15V 301 165 102 240 64.9 7.5 to 40 5 2 × 10µF 2220 50V 4 × 100µF 1210 6.3V 8.5V to 15V 162 210 75.0 315 45.3 10.5 to 40 8 2 × 10µF 2220 50V 4 × 47µF 1210 10V 8.5V to 15V 90.9 260 59.0 500 23.7 16 to 40 12 2 × 10µF 2220 50V 4 × 22µF 1210 16V AUX 56.2 300 48.7 500 23.7 20.5 to 40 15 1 × 10µF 2220 50V 4 × 22µF 1210 16V AUX 44.2 350 40.2 500 23.7 26 to 40 18 1 × 10µF 2220 50V 4 × 10µF 1812 25V 8.5V to 15V 36.5 400 31.6 500 23.7 34 to 40 24 1 × 10µF 2220 50V 4 × 10µF 1812 25V 8.5V to 15V 26.7 430 28.7 500 23.7 4.5 to 56 –3.3 2 × 4.7µF 2220 100V 5 × 100µF 1812 6.3V 8.5V to 15V Above Output 301 115 154 155 115 4.5 to 55 –5 2 × 4.7µF 2220 100V 4 × 100µF 1210 6.3V 8.5V to 15V Above Output 162 190 90.9 230 68.2 10.5 to 52 –8 2 × 4.7µF 2220 100V 4 × 47µF 1210 10V 8.5V to 15V Above Output 90.9 260 59.0 350 40.2 16 to 48 –12 2 × 4.7µF 2220 100V 4 × 22µF 1210 16V AUX 56.2 300 48.7 500 23.7 8027fd 16 For more information www.linear.com/LTM8027

LTM8027 TYPICAL APPLICATIONS 3.3V V Step-Down Converter 5V V Step-Down Converter OUT OUT 4.5V TOV 4I0NV* 10µF VIN VOUT 34V.AO3UVT 7.5V TO 6V0IVN 4.7µF VIN VOUT 54VVAOUT ×2 1M LTM8027 ×2 1M LTM8027 RUN BIAS1 9V RUN BIAS1 9V SS BIAS2 SS BIAS2 100µF 100µF SYNC AUX ×4 SYNC AUX ×4 RT ADJ RT ADJ GND GND 102k 301k 75k 162k *RUNNING VOLTAGE. SEE APPLICATIONS 3845 TA02 3845 TA03 INFORMATION FOR START-UP DETAILS 18V V Step-Down Converter –12V V Positive-to-Negative Converter OUT OUT 26V TO 6V0IVN 4.7µF VIN VOUT 13V8AOVUT 20V TO 4V8IVN 4.7µF VIN VOUT ×2 1M LTM8027 4A SURGE ×2 1M LTM8027 RUN BIAS1 9V RUN BIAS1 SS BIAS2 SS BIAS2 SCHOTTKY SYNC AUX 1×04µF SYNC AUX 2×24µF DOIPOTDIOENAL RT ADJ RT ADJ 31.6k GND 36.5k 48.7k GND 56.2k VOUT –12V 3845 TA07 3A 3845 TA05 PACKAGE PHOTOGRAPHS LGA BGA 8027fd 17 For more information www.linear.com/LTM8027

LTM8027 PACKAGE DESCRIPTION Please refer to http://www.linear.com/product/LTM8027#packaging for the most recent package drawings. DETAIL A 11 10 9 8 7 6 5 4 3 2 1 C(0.30)ABPAD 1 TATION LGA 113 0807 REV Ø N C RIE O G D W N E M VIE LOADI 12.70BSC HGF PACKAGE BOTTO LTMXXXXXXModuleµ ACKAGE IN TRAY P J K LGA Package113-Lead (15mm 15mm 4.32mm)××(Reference LTC DWG # 05-08-1756 Rev Ø) 4.22 – 4.42 12.70BSCMOLDSUBSTRATECAP 0.27 – 0.373.95 – 4.05 ZZ1.27 bbBSCb // DETAIL B aaa ZPADSLSEE NOTES3DETAIL B 0.635 0.025 SQ. 113x± SYXeee DETAIL A NOTES:1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 2. ALL DIMENSIONS ARE IN MILLIMETERS 3 LAND DESIGNATION PER JESD MO-222, SPP-010 4DETAILS OF PAD #1 IDENTIFIER ARE OPTIONAL,BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.THE PAD #1 IDENTIFIER MAY BE EITHER A MOLD OR COMPONENTPIN “A1”MARKED FEATURE 5. PRIMARY DATUM -Z- IS SEATING PLANETRAY PIN 16. THE TOTAL NUMBER OF PADS: 113BEVEL SYMBOLTOLERANCE aaa0.15 bbb0.10 eee0.05 Y 15BSC X 053.6 080.5 018.3 045.2 UT W O 15BSC KAGE TOP VIE 000770220...110 STED PCB LAYTOP VIEW C E A G P G 045.2 U S 018.3 080.5 053.6 aaa Z PAD 1ORNER 4 6.350 5.080 3.810 2.540 1.270 0.000 1.270 2.540 3.810 5.080 6.350 C 8027fd 18 For more information www.linear.com/LTM8027

LTM8027 PACKAGE DESCRIPTION Please refer to http://www.linear.com/product/LTM8027#packaging for the most recent package drawings. 4.92mm)80 Rev Ø) DETAIL ASEE NOTES 71067821431195 PAD 1 A bB C D E F G H J Ke L ebSEE NOTES G3 PACKAGE BOTTOM VIEW NOTES:1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 2. ALL DIMENSIONS ARE IN MILLIMETERS 3 BALL DESIGNATION PER JESD MS-028 AND JEP95 4DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL,BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE 5. PRIMARY DATUM -Z- IS SEATING PLANE 6. SOLDER BALL COMPOSITION IS 96.5% Sn/3.0% Ag/0.5% Cu 7PACKAGE ROW AND COLUMN LABELING MAY VARY !AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY LTMXXXXXXµModule COMPONENTPIN “A1” TRAY PIN 1BEVELPACKAGE IN TRAY LOADING ORIENTATIONBGA 113 0414 REV Ø BGA Package113-Lead (15mm 15mm ××BGA Package(Reference LTC DWG # 05-08-19113-Lead (15mm 15mm 4.92mm)××(Reference LTC DWG # 05-08-1980 Rev Ø) ZA A2aaa Z A1 ccc Z b1MOLDCAPFSUBSTRATE H1H2 ZZ bbDETAIL Bb // Øb (113 PLACES) MXYZdddMZeee DETAIL BPACKAGE SIDE VIEW DETAIL A DIMENSIONS MINSYMBOLNOMMAXNOTES4.72A4.925.120.50A10.600.704.22A24.324.420.60b0.750.900.60b10.630.66D15.00E15.00e1.27F12.70G12.700.27H10.320.373.95H24.004.05aaa0.15bbb0.10ccc0.20ddd0.30eee0.15 TOTAL NUMBER OF BALLS: 113 D X 6.350 5.080 3.810 2.540 1.270 0.000 1.270 2.540 3.810 5.080 6.350 Y 053.6 080.5 018.3 045.2 UT E PACKAGE TOP VIEW 000047705220....2110 UGGESTED PCB LAYOTOP VIEW S 018.3 080.5 053.6 PAD “A1”CORNER 4 Z aaa 0.630 ±0.025 Ø 113x 8027fd 19 For more information www.linear.com/LTM8027

LTM8027 PACKAGE DESCRIPTION Pin Assignment Table (Arranged by Pin Number) PIN NAME PIN NAME PIN NAME A1 GND D6 GND H5 GND A2 ADJ D7 GND H6 GND A3 BIAS2 D8 GND H7 GND A4 RUN D9 GND H8 GND A5 SS D10 GND H9 V OUT A6 BIAS1 D11 GND H10 V OUT A7 AUX E1 GND H11 V OUT A8 GND E2 GND J1 V IN A9 GND E3 GND J2 V IN A10 GND E4 GND J3 V IN A11 GND E5 GND J5 GND B1 RT E6 GND J6 GND B2 GND E7 GND J7 GND B3 GND E8 GND J8 GND B4 GND E9 V J9 V OUT OUT B5 GND E10 V J10 V OUT OUT B6 GND E11 V J11 V OUT OUT B7 GND F1 GND K1 V IN B8 GND F2 GND K2 V IN B9 GND F3 GND K3 V IN B10 GND F4 GND K5 GND B11 GND F5 GND K6 GND C1 SYNC F6 GND K7 GND C2 GND F7 GND K8 GND C3 GND F8 GND K9 V OUT C4 GND F9 V K10 V OUT OUT C5 GND F10 V K11 V OUT OUT C6 GND F11 V L1 V OUT IN C7 GND G5 GND L2 V IN C8 GND G6 GND L3 V IN C9 GND G7 GND L5 GND C10 GND G8 GND L6 GND C11 GND G9 V L7 GND OUT D1 GND G10 V L8 GND OUT D2 GND G11 V L9 V OUT OUT D3 GND H1 V L10 V IN OUT D4 GND H2 V L11 V IN OUT D5 GND H3 V IN 8027fd 20 For more information www.linear.com/LTM8027

LTM8027 REVISION HISTORY REV DATE DESCRIPTION PAGE NUMBER A 1/11 Changed Shutdown Current Supply to 9µA in Features. 1 Updated Absolute Maximum Ratings section. 2 Updated V and Note 3 in Electrical Characteristics section. 3 BIAS1(MINOV) Replaced graph 9. 4 Updated Pin Functions section. 9 Text edits to Applications Information. 11-16 Updated Typical Applications. 17, 18 Updated Related Parts. 22 B 9/11 Added (Note 3) notation to the Order Information section. 2 Updated minimum spec for V . 3 BIAS2 Updated descriptions for AUX and BIAS2 in the Pin Functions section. 9 Updated text in the Input Power Requirements section. 11 Added text to end of the BIAS Power section. 12 C 05/14 Add BGA package option 1, 2 Add advisory notice 9 Add BGA package drawing 19 D 12/16 Corrected R value from 162k to 75k 12 T Updated Related Parts 22 8027fd Information furnished by Linear Technology Corporation is believed to be accurate and reliable. 21 However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

LTM8027 TYPICAL APPLICATION 15V V Step-Down Converter OUT VOUT 20.5V TO 6V0IVN VIN VOUT 135.5VA 4.7µF ×2 1M LTM8027 4A SURGE RUN BIAS1 SS BIAS2 22µF SYNC AUX ×4 RT ADJ GND 40.2k 44.2k 3845 TA04 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTM8050 2A, 58V DC/DC µModule Regulator 3.6V ≤ VIN ≤ 58V, 0.8V ≤ VOUT ≤ 24V, Synchronizable, Parallelable, 9mm × 15mm × 4.92mm BGA LTM4601/ 12A DC/DC µModule Regulator with PLL, Output Synchronizable, PolyPhase Operation, LTM4601-1 Version has no Remote LTM4601A Tracking/Margining and Remote Sensing Sensing LTM4603 6A DC/DC µModule with PLL and Output Tracking/ Synchronizable, PolyPhase Operation, LTM4603-1 Version has no Remote Margining and Remote Sensing Sensing, Pin Compatible with the LTM4601 LTM4604A 4A Low VIN DC/DC µModule Regulator 2.375V ≤ VIN ≤ 5V, 0.8V ≤ VOUT ≤ 5V, 9mm × 15mm × 2.3mm LGA LTM4608A 8A Low VIN DC/DC µModule Regulator 2.7V ≤ VIN ≤ 5V, 0.6V ≤ VOUT ≤ 5V, 9mm × 15mm × 2.8mm LGA LTM8020 200mA, 36V DC/DC µModule Regulator Fixed 450kHz Frequency, 1.25V ≤ VOUT ≤ 5V, 6.25mm × 6.25mm × 2.32mm LGA LTM8022 1A, 36V DC/DC µModule Regulator Adjustable Frequency, 0.8V ≤ VOUT ≤ 5V, 9mm × 11.25mm × 2.82mm LGA, Pin Compatible to the LTM8023 LTM8023 2A, 36V DC/DC µModule Regulator Adjustable Frequency, 0.8V ≤ VOUT ≤ 5V, 9mm × 11.25mm × 2.82mm LGA, Pin Compatible to the LTM8022 LTM8025 3A, 36V DC/DC µModule Regulator 0.8V ≤ VOUT ≤ 24V, 9mm × 15mm × 4.32mm LGA LTM4624 14V , 4A, Step-Down µModule Regulator in Tiny 4V ≤ V ≤ 14V, 0.6V ≤ V ≤ 5.5V, V Tracking, PGOOD, Light Load Mode, IN IN OUT OUT 6.25mm × 6.25mm × 5.01mm BGA Complete Solution in 1cm2 (Single Sided PCB) LTM4644 Quad 4A, 14V Step-Down µModule Regulator with 4V ≤ V ≤ 14V, 0.6V ≤ V ≤ 5.5V, CLK Input and Output, V Tracking, IN OUT OUT Configurable Output Array PGOOD, 9mm × 15mm × 5.01mm BGA LTM8064 58VIN, 6A CVCC Step-Down μModule Regulator 6V ≤ VIN ≤ 58V, 1.2V ≤ VOUT ≤ 36V, 16mm × 11.9mm × 4.92mm BGA Package LTM8056 58VIN, 48 VOUT Buck-Boost μModule Regulator 5V ≤ VIN ≤ 58V, 1.2V ≤ VOUT ≤ 48V, 15mm × 15mm × 4.92mm BGA Package LTM8053 40VIN, 3.5A Step-Down μModule Regulator 3.4V ≤ VIN ≤ 40V, 0.97V ≤ VOUT ≤ 15V, 6.25mm × 9mm × 3.32mm BGA Package 8027fd 22 Linear Technology Corporation LT 1216 REV D • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 For more information www.linear.com/LTM8027 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTM8027  LINEAR TECHNOLOGY CORPORATION 2009