LTC2801/LTC2802/ LTC2803/LTC2804 1.8V to 5.5V RS-232 Single and Dual Transceivers FeatureS deScriPtion n 1.8V to 5.5V Supply Voltage The LTC®2801/LTC2802/LTC2803/LTC2804 are single and n Single and Dual Transceivers dual RS-232 transceivers in narrow SSOP and chip-scale n High-Speed Operation DFN packages. All operate over a supply range of 1.8V to 1Mbps for 250pF/3kΩ Load (LTC2802, LTC2804) 5.5V, which permits operation directly from two alkaline, 250kbps for 1nF/3kΩ Load NiCd or NiMH cells. An integrated DC-to-DC converter 100kbps for 2.5nF/3kΩ TIA/EIA-232-F Load generates power supplies for driving RS-232 levels. A n Low-Power 1µA Shutdown and 15µA Receivers- logic supply pin allows easy interfacing with different logic Active Modes levels independent of the DC-DC supply. n No Damage or Latchup to ±10kV ESD on RS-232 These parts are compatible with the TIA/EIA-232-F stan- Interface dard. Driver outputs are protected from overload and can n Logic Supply Pin for Easy Level-Shifting to UART or be shorted to ground or up to ±15V without damage. To Microprocessor extend battery life, receivers can be kept active, operating n Low-Latency Output Enable Allows Line Sharing and at reduced speed, with only 15µA current. In shutdown Half-Duplex Operation mode, current is further reduced to 1µA. n True RS-232 Compliant Output Levels n Small Footprint: Product Selection Guide LTC2801/LTC2802 4mm × 3mm DFN Package LTC2803/LTC2804 Narrow SSOP-16 and DRIVERS AND MAXIMUM 5mm × 3mm DFN Packages PART NUMBER RECEIVERS DATA RATE MODES* PACKAGE LTC2801 1 + 1 0.25Mbps SD, RA, DD, AO DFN-12 aPPlicationS LTC2802 1 + 1 1Mbps SD, RA, DD, AO DFN-12 LTC2803 2 + 2 0.25Mbps SD, RA, DD, AO DFN-16 n Battery-Powered Systems LTC2803-1 2 + 2 0.25Mbps SD, AO SSOP-16 n Computers and Consumer Electronics LTC2804 2 + 2 1Mbps SD, RA, DD, AO DFN-16 n Diagnostic Ports LTC2804-1 2 + 2 1Mbps SD, AO SSOP-16 L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear *SD = Shutdown, RA = Receiver Active (low power), DD = Drivers Technology Corporation. All other trademarks are the property of their respective owners. Disabled, AO = All On tyPical aPPlication 1.8V TO 5.5V LTC2802 at 1.8V and 1Mbps L1 10µH C4 1µF VCC SW 2V/DIV TIN VL LTC2802 C2210nF PS CAP OFF ON MODE 5V/DIV TOUT TIN TOUT ROUT RIN 2V/DIV ROUT GND VDD VEE VCC = VL = 1.8V 400ns/DIV 2801 TA01b WRAPPING DATA C2 C3 TOUT LOAD = 250pF + RIN 1µF 1µF ROUT LOAD = 150pF 2801 TA01a 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 abSolute MaxiMuM ratinGS (Note 1) Input Supplies PS, ON/OFF .....................................–0.3V to (V + 0.3V) L V ...........................................................–0.3V to 7V RIN, R1IN, R2IN ..........................................–25V to 25V CC V .........................................................–0.3V to 6.7V TOUT, T1OUT, T2OUT..................................–15V to 15V L Generated Supplies ROUT, R1OUT, R2OUT ....................–0.3V to (V + 0.3V) L V .................................................V –0.3V to 7.5V Operating Temperature DD CC V ........................................................0.3V to –7.5V LTC280XC ................................................0°C to 70°C EE V – V ..............................................................14V LTC280XI .............................................–40°C to 85°C DD EE SW ..................................................–0.3V to V + 0.3V Storage Temperature Range ..................–65°C to 125°C DD CAP ..................................................+0.3V to V – 0.3V Lead Temperature (Soldering, 10 sec) EE TIN, T1IN, T2IN, MODE ................................–0.3V to 7V GN Package ......................................................300°C Pin conFiGuration LTC2801, LTC2802 LTC2803, LTC2804 LTC2803-1, LTC2804-1 1-Driver/1-Receiver 2-Driver/2-Receiver 2-Driver/2-Receiver TOP VIEW TOP VIEW TOP VIEW R1IN 1 16 R1OUT R1IN 1 16 R1OUT RIN 1 12 ROUT R2IN 2 15 R2OUT R2IN 2 15 R2OUT TOUT 2 11 TIN T1OUT 3 14 T1IN T1OUT 3 14 T1IN VCC 3 13 10 VL T2OUT 4 17 13 T2IN T2OUT 4 13 T2IN VDD 4 9 MODE VCC 5 12 VL VCC 5 12 VL GSNWD 56 VEE 87 PCSAP VSDWD 67 1110 MPSODE VSDWD 67 1110 OCANP/OFF GND 8 VEE 9 CAP DE PACKAGE GND 8 9 VEE 12-LEAD (4mm (cid:115) 3mm) PLASTIC DFN DHC PACKAGE GN PACKAGE EXPTOJSMEADX =P A1D25 (°PCIN, θ 1J3A )= I S4 3V°ECE/,W M, UθSJCT = B 4E. 3S°OCL/DWE (R4E LDa TyeOr )P CB TJMAX =1 162-5L°ECA,D θ (J5A m= m44 (cid:115)° C3/mWm, θ)J PC L=A 4S.T3I°CC /DWF N(4 L ayer) TJMAX 1=6 1-2L5E°ACD, θ(NJAA R= R1O10W° C0/.W15, 0θ)J CP =L A4S0T°ICC/ WSS (O4 PL ayer) EXPOSED PAD (PIN 17) IS VEE, MUST BE SOLDERED TO PCB order inForMation LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC2801CDE#PBF LTC2801CDE#TRPBF 2801 12-Lead (4mm × 3mm) Plastic DFN 0°C to 70°C LTC2801IDE#PBF LTC2801IDE#TRPBF 2801 12-Lead (4mm × 3mm) Plastic DFN –40°C to 85°C LTC2802CDE#PBF LTC2802CDE#TRPBF 2802 12-Lead (4mm × 3mm) Plastic DFN 0°C to 70°C LTC2802IDE#PBF LTC2802IDE#TRPBF 2802 12-Lead (4mm × 3mm) Plastic DFN –40°C to 85°C LTC2803CDHC#PBF LTC2803CDHC#TRPBF 2803 16-Lead (5mm × 3mm) Plastic DFN 0°C to 70°C LTC2803IDHC#PBF LTC2803IDHC#TRPBF 2803 16-Lead (5mm × 3mm) Plastic DFN –40°C to 85°C LTC2804CDHC#PBF LTC2804CDHC#TRPBF 2804 16-Lead (5mm × 3mm) Plastic DFN 0°C to 70°C LTC2804IDHC#PBF LTC2804IDHC#TRPBF 2804 16-Lead (5mm × 3mm) Plastic DFN –40°C to 85°C LTC2803CGN-1#PBF LTC2803CGN-1#TRPBF 28031 16-Lead (Narrow 0.150) Plastic SSOP 0°C to 70°C LTC2803IGN-1#PBF LTC2803IGN-1#TRPBF 2803I1 16-Lead (Narrow 0.150) Plastic SSOP –40°C to 85°C LTC2804CGN-1#PBF LTC2804CGN-1#TRPBF 28041 16-Lead (Narrow 0.150) Plastic SSOP 0°C to 70°C LTC2804IGN-1#PBF LTC2804IGN-1#TRPBF 2804I1 16-Lead (Narrow 0.150) Plastic SSOP –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. Consult LTC Marketing for information on non-standard lead based finish parts. 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/ 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 electrical characteriSticS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25°C, V = 1.8V to 5.5V, V = 1.8V to 5.5V, Normal Mode. Typical values are A CC L given for V = V = 3.3V and T = 25°C, unless otherwise noted. CC L A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Power Supplies I V Supply Current Outputs Unloaded CC CC Normal Mode (Note 3) 2.3 mA Receivers Active Mode l 1 10 µA Shutdown Mode l 1 10 µA I V Supply Current Outputs Unloaded L L Normal Mode (LTC2801, LTC2802) l 0.08 0.15 mA Normal Mode (LTC2803, LTC2804) l 0.15 0.30 mA Receivers Active Mode l 15 30 µA Shutdown Mode l 1 10 µA Driver V Output Voltage R = 3kΩ Low l –5 –5.7 V OLD L V Output Voltage R = 3kΩ High l 5 6.2 V OHD L V Logic Input Hysteresis 0.6 V HYSD IOSD Output Short Circuit Current VL = VCC = 5.5V; VTOUT = 0V l ±35 ±70 mA IPOLD Power-Off Output Leakage Current VL = VCC = VDD = VEE = 0V; VTOUT = ±2V l ±0.1 ±10 µA IOLD Output Leakage Current Shutdown or Receivers Active or l ±0.1 ±10 µA Drivers Disabled Modes, –15V ≤ VTOUT ≤ 15V Receiver V Input Thresholds Receivers Active Mode l 0.8 1.5 2.4 V IR V Input Thresholds Normal Mode, Input Low l 0.8 1.3 V ILR V Input Thresholds Normal Mode, Input High l 1.7 2.5 V IHR VHYSR Input Hysteresis Normal Mode l 0.1 0.4 1.0 V V Output Voltage Output Low, I = 1mA (Sinking) l 0.2 0.4 V OLR ROUT V Output Voltage Output High, I = –1mA (Sourcing) l V –0.4 V –0.2 V OHR ROUT L L RIN Input Resistance –15V ≤ VRIN ≤ 15V l 3 5 7 kW IOSR Output Short Circuit Current VL = 5.5V; 0V ≤ VROUT ≤ VL l ±25 ±50 mA Logic Logic Input Voltage Threshold l 0.4 0.67 • V V L I Logic Input Current l ±1 µA IN Power Supply Generator VDD Regulated VDD Output Voltage Driver RL = 3kW (Note 3) LTC2801, LTC2802: V = V 7 V TIN L LTC2803, LTC2804: V = V , V = 0V T1IN L T2IN VEE Regulated VEE Output Voltage Driver RL = 3kW (Note 3) LTC2801, LTC2802: V = V –6.3 V TIN L LTC2803, LTC2804: V = V , V = 0V T1IN L T2IN 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 SwitchinG characteriSticS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25°C, V = 1.8V to 5.5V, V = 1.8V to 5.5V, Normal Mode. Typical values are A CC L given for V = V = 3.3V and T = 25°C, unless otherwise noted. CC L A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Maximum Data Rate LTC2801, LTC2803 (Note 3) RL = 3kW, CL = 2.5nF l 100 kbps RL = 3kW, CL = 1nF l 250 kbps LTC2802, LTC2804 (Note 3) RL = 3kW, CL = 2.5nF l 100 kbps RL = 3kW, CL = 1nF l 250 kbps RL = 3kW, CL = 250pF l 1000 kbps Driver SR(D) Driver Slew Rate LTC2801, LTC2803 (Figure 1) VCC = VL = 1.8V, RL = 3kW, CL = 2.5nF l 4 V/µs VCC = VL = 5.5V, RL = 3kW, CL = 50pF l 30 V/µs LTC2802, LTC2804 (Figure 1) VCC = VL = 1.8V, RL = 3kW, CL = 2.5nF l 4 V/µs VCC = VL = 5.5V, RL = 3kW, CL = 50pF l 150 V/µs tPHLD, tPLHD Driver Propagation Delay RL = 3kW, CL = 50pF (Figure 2) LTC2801, LTC2803 l 1 2 µs LTC2802, LTC2804 l 0.2 0.5 µs tSKEWD Driver Skew RL = 3kW, CL = 50pF (Figure 2) LTC2801, LTC2803 100 ns LTC2802, LTC2804 50 ns tPZHD, tPZLD Driver Output Enable Time PS = VL, MODE = ↑, RL = 3kW, CL = 50pF l 0.6 2 µs (Figure 4) tPHZD, tPLZD Driver Output Disable Time PS = VL, MODE = ↓, RL = 3kW, CL = 50pF l 0.3 2 µs (Figure 4) Receiver t , t Receiver Propagation Delay C = 150pF (Figure 3) l 0.2 0.4 µs PHLR PLHR L t Receiver Skew C = 150pF (Figure 3) 50 ns SKEWR L t , t Receiver Rise or Fall Time C = 150pF (Figure 3) l 60 200 ns RR FR L tPZHR, tPZLR Shutdown to Receiver Output Enable PS = MODE = ↑ or ON/OFF = ↑, l 5 15 µs RL = 1kW, CL = 150pF (Figure 5) tPHZR, tPLZR Receiver Output Disable upon Shutdown PS = MODE = ↓ or ON/OFF = ↓, l 0.15 0.3 µs RL = 1kW, CL = 150pF (Figure 5) Power Supply Generator V /V Supply Rise Time (Notes 3 and 4) l 0.2 2 ms DD EE Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 2: All currents into pins are positive; all voltages are referenced to may cause permanent damage to the device. Exposure to any Absolute GND unless otherwise specified. Maximum Rating condition for extended periods may affect device Note 3: Guaranteed by other measured parameters and not tested directly. reliability and lifetime. Note 4: Time from PS ↑ or ON/OFF ↑ until VDD ≥ 5V and VEE ≤ –5V. 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 teSt circuitS TOUT TIN VL 0V TIN RL CL tTHL tTLH 3V 3V VOHD TOUT –3V –3V VOLD 6V SR(D) = 2801 F01 TIN tr, tf ≤ 40ns tTHL or tTLH Figure 1. Driver Slew Rate Measurement TOUT VL TIN 1/2 VL 1/2 VL 0V TIN RL CL tPHLD tPLHD VOHD TOUT 0V 0V VOLD tSKEWD = |tPHLD–tPLHD| 2801 F02 TIN tr, tf ≤ 40ns Figure 2. Driver Timing Measurement ROUT 3V RIN 1.5V 1.5V –3V RIN CL tPHLR tPLHR ROUT VOHR 1/2 VL 1/2 VL VOLR tSKEWR = |tPHLR–tPLHR| 2801 F03 RIN tr, tf ≤ 40ns Figure 3. Receiver Timing Measurement MODE VL 1/2 VL 1/2 VL 0V tPZHD tPHZD 0 OR VL TOUT TOUT 5V VOHD – 0.5VVOHD 0V MODE RL CL tPZLD tPLZD 0V TOUT –5V VOLD + 0.5VVOLD 2801 F04 MODE tr, tf ≤ 40ns Figure 4. Driver Enable/Disable Times 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 teSt circuitS GND VL PS AND MODE VL 1/2 VL 1/2 VL RL 0V tPZHR tPHZR –3V OR 3V ROUT ROUT 1/2 VL VOHR – 0.5VVOHR 0V PS AND MODE CL tPZLR tPLZR ROUT VL 1/2 VL VOLR + 0.5V VOLR 2801 F05 PS AND MODE tr, tf ≤ 40ns Figure 5. Receiver Enable/Disable Times tyPical PerForMance characteriSticS T = 25°C, V = V = 3.3V unless otherwise noted. A CC L Drivers Disabled Mode Supply LTC2803 at 1.8V and 250kbps LTC2804 at 1.8V and 1Mbps Current vs Supply Voltage 3.0 T1IN T1IN TA = 85°C VCC = VL 2V/DIV 2V/DIV mA)2.5 T1OUT T1OUT ENT (2.0 TA = 25°C R T2OUT T2OUT UR TA = –40°C C 10V/DIV 10V/DIV Y 1.5 L P P U R1OUT R1OUT S1.0 2V/DIV R2OUT 2V/DIV R2OUT 0.5 0 VCC = VL = 1.8V 2µs/DIV VCC = VL = 1.8V 400ns/DIV 1 2 3 4 5 6 WRAPPING DATA WRAPPING DATA SUPPLY VOLTAGE (V) TOUT LOAD = 1nF + RIN TOUT LOAD = 250pF + RIN ROUT LOAD = 150pF 2801 G01 ROUT LOAD = 150pF 2801 G02 2801 G03 Supply Current vs Supply Voltage Supply Current vs Load (Dual Transceiver) Supply Current vs Data Rate Capacitance (Dual Transceiver) 60 100 100 ALL DRIVERS SWITCHING ALL DRIVERS SWITCHING VCC = VL VCC = VL = 1.8V 250kbps SUPPLY CURRENT (mA) 54320000 1252k0b.p8skbps250kbps CRL L= = 1 3nkF SUPPLY CURRENT (mA) 864000 RL = 3k 1nF 22155n00FppFF SUPPLY CURRENT (mA) 864000 20.8kbps 125kbps 20 20 10 VCC = VL = 1.8V LTC2804 LTC2804 LTC2804 RL = 3k LTC2803 LTC2802 LTC2803 ALL DRIVERS SWITCHING 0 0 0 1 2 3 4 5 6 0 200 400 600 800 1000 1 2 3 4 5 SUPPLY VOLTAGE (V) DATA RATE (kbps) LOAD CAPACITANCE (nF) 2801 G04 2801 G05 2801 G06 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 tyPical PerForMance characteriSticS T = 25°C, V = V = 3.3V unless otherwise noted. A CC L Receiver Input Threshold Receiver Output Voltage vs Temperature vs Load Current Receiver Output Duty Cycle 3.0 6 100 VL = 5.5V VL = 5.5V RIN = ±3V VL = 3.3V VL = 3.3V CL = 150pF 2.5 VL = 1.8V 5 VL = 1.8V 80 D VOLTAGE (V) 21..05 INPUT HIGH VOLTAGE (V) 43 UTY CYCLE (%) 60 RALEICVEEI VMEORDSE NORMAL RESHOL 1.0 INPUT LOW OUTPUT 2 SITIVE D 40 MODE H O T 0.5 1 P 20 VL = 5.5V VL = 3.3V VL = 1.8V 0 0 0 –50 –25 0 25 50 75 100 125 0 1 2 3 4 5 6 7 8 10 100 1000 10000 TEMPERATURE (°C) LOAD CURRENT (mA) DATA RATE (kbps) 2801 GO9 2801 GO7 2801 GO8 Driver Slew Rate Driver Short-Circuit Current Shutdown or Drivers Disabled Mode vs Load Capacitance vs Temperature Driver Leakage vs Temperature 80 60 10–6 FALLING (LTC2802/04) 70 RISING (LTC2802/04) FALLING (LTC2801/03) A) 50 10–7 RISING (LTC2801/03) m W RATE (V/µs) 654000 CUIT CURRENT ( 4300 SSINOKUIRNCGING GE CURRENT (A)1100––89 V(TVO(TUOTU) T=) 1=5 –V1 O5RV SLE 30 T-CIR 20 EAKA 20 HOR L10–10 S 10 10 REGULATOR CAN LIMIT FURTHER 0 0 10–11 0 1 2 3 4 5 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 LOAD CAPACITANCE (nF) TEMPERATURE (°C) TEMPERATURE (°C) 2801 G10 2801 G11 2801 G12 Logic Input Threshold LTC2804 Driver Outputs Exiting LTC2804 Driver Outputs vs V Supply Voltage Shutdown Enable/Disable L 3.0 TA = 85°C TA = 25°C 2.5 TA = –40°C 2V/DIV MODE AND PS 2V/DIV MODE V) INPUT HIGH GE ( 2.0 A T L O LD V 1.5 T1OUT T1OUT O H 5V/DIV 5V/DIV HRES 1.0 INPUT LOW T2OUT T2OUT T 0.5 0 1 2 3 4 5 6 VCC = 3.3V 100µs/DIV VCC = 3.3V 2µs/DIV VL SUPPLY VOLTAGE (V) VL = 1.8V VL = 1.8V LOAD = 3k + 2.5nF LOAD = 3k + 250pF 2801 G13 2801 G14 2801 G15 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 Pin FunctionS PIN NUMBER 2801 2803 2803-1 PIN NAME 2802 2804 2804-1 COMMENTS V 3 5 5 Input Supply (1.8V-5.5V). Bypass to GND with a 1µF capacitor. CC V 4 6 6 Generated Positive Supply Voltage for RS-232 Driver (7V). Connect a 1µF capacitor between DD V and GND. DD V 13* 17* 9 Generated Negative Supply Voltage for RS-232 Driver (–6.3V). Connect a 1µF capacitor EE between V and GND. EE SW 5 7 7 Switch Pin. Connect a 10µH inductor between SW and V . CC GND 6 8 8 Ground. CAP 7 9 10 Charge Pump Capacitor for Generated Negative Supply Voltage. Connect a 220nF capacitor between CAP and SW. V 10 12 12 Logic Supply (1.8V-5.5V) for the receiver outputs, driver inputs, and control inputs. This pin L should be bypassed to GND with a 220nF capacitor if it’s not tied to V . CC TIN (T1IN, T2IN) 11 14, 13 14, 13 Driver Input(s), referenced to V . L TOUT (T1OUT, T2OUT) 2 3, 4 3, 4 RS-232 Driver Output(s). RIN (R1IN, R2IN) 1 1, 2 1, 2 RS-232 Receiver Input(s). Includes internal 5kΩ termination resistor(s). ROUT (R1OUT, R2OUT) 12 16, 15 16, 15 Receiver Output(s), referenced to V . Output is short-circuit protected to GND/V /V , and is L CC L high impedance in Shutdown mode, allowing data line sharing. PS 8 10 — Power Supply control pin, referenced to V . Enables the integrated DC-DC converter. L MODE 9 11 — Mode control pin, referenced to V . See Table 1 for functionality. L ON/OFF — — 11 Transceiver enable pin, referenced to V . A logic low puts the device in Shutdown mode and L places both driver and receiver outputs in a high impedance state. *Backside thermal pad Mode control Table 1. LTC2801, LTC2802, LTC2803, LTC2804 RECEIVER DRIVER MODE NAME PS MODE OUTPUT(S) DC-DC OUTPUT(S) I * I * VCC VL SHUTDOWN L L HI-Z OFF HI-Z 1µA 1µA RECEIVER(S) ACTIVE L H ON OFF HI-Z 1µA 15µA DRIVER(S) DISABLED H L ON ON HI-Z 2.1mA 80µA OR 150µA NORMAL H H ON ON ON 2.3mA 80µA OR 150µA Table 2. LTC2803-1, LTC2804-1 RECEIVER DRIVER MODE NAME ON/OFF OUTPUTS DC-DC OUTPUTS I * I * VCC VL SHUTDOWN L HI-Z OFF HI-Z 1µA 1µA NORMAL H ON ON ON 2.3mA 150µA *Typical currents for static drivers. Normal mode currents are for unloaded outputs. 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 Feature SuMMary FEATURE 2801 2802 2803 2803-1 2804 2804-1 DRIVERS and RECEIVERS 1 + 1 1 + 1 2 + 2 2 + 2 2 + 2 2 + 2 PACKAGE DFN-12 DFN-12 DFN-16 SSOP-16 DFN-16 SSOP-16 1.8V - 5.5V OPERATION l l l l l l 1.8V - 5.5V LOGIC SUPPLY (V ) l l l l l l L SHUTDOWN (1µA) l l l l l l RECEIVER(S) ACTIVE (15µA) l l l l DRIVER(S) DISABLE l l l l 100kb/s for R = 3kΩ, C = 2.5nF l l l l l l L L 250kb/s for R = 3kΩ, C = 1nF l l l l l l L L 1Mb/s for R = 3kΩ, C = 250pF l l l L L block diaGraM L1 C1 10µH 220nF 1.8V TO 5.5V C4 VCC SW CAP 1µF VDD VL VEE 1.8V TO 5.5V BOOST C5 REGULATOR C3 C2 220nF 1µF 1µF VL VDD T2IN T2OUT ** ** T1IN T1OUT VL GND VEE R2OUT R2IN ** ** 5k R1OUT R1IN VL LTC2801 PS 5k LTC2802 GND ** LTC2803 LTC2803 MODE LTC2804 LTC2804 CONTROL LTC2803-1 LTC2803-1 ON/OFF LTC2804-1 LTC2804-1 2801 BD GND 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 aPPlicationS inForMation Overview ANY VOLTAGE FROM ANY VOLTAGE FROM 1.8V TO 5.5V 1.8V TO 5.5V The LTC2801 family of RS-232 transceivers operates on a V supply of 1.8V to 5.5V, utilizing a switching regula- VCC CC tor to generate the necessary higher voltage rails for the VL drivers. The transceivers interface with logic operating on any supply from 1.8V to 5.5V, independent of the V EXTERNAL RS-232 CC DEVICE voltage. Depending on the device, one or two control pins are available to invoke Shutdown, Receiver Active and 2801 F07 Driver Disable features. Figure 7. V and V Are Independent CC L DC-DC Converter Power-Saving Modes The on-chip DC-DC converter operates from the V CC input, generating a 7V V supply and a charge pumped When the DC-DC converter and drivers are turned off (PS DD – 6.3V VEE supply, as shown in Figure 6. VDD and VEE and MODE or ON/OFF = logic low), VCC supply current is power the output stage of the drivers and are regulated reduced to 1µA. Tables 1 and 2 summarize the modes for to levels that guarantee greater than ±5V output swing. each device. The DC-DC converter requires a 10µH inductor (L1) and In Shutdown mode, V supply current is reduced to 1µA, L a bypass capacitor (C4) of at least 1µF. The recommended and both receiver and driver outputs assume a high im- size for the charge pump capacitor (C1) is 220nF and for pedance state. the storage capacitors (C2 and C3) is 1µF. Larger storage In Receivers Active mode, the quiescent V supply current capacitors up to 4.7µF may be used if C1 is kept at 20% to L is reduced to 15µA and the driver outputs assume a high 50% their size and C4 is also scaled. Locate C1-C4 close impedance state. The receivers operate at a reduced rate to their associated pins. (typically 100 kbps) with hysteresis turned off. L1 C1 10µH 220nF Half-Duplex Operation 1.8V TO 5.5V 1Cµ4F VCC SW CAP When the DC-DC converter is kept on (PS = logic high), VDD MODE serves as a low-latency driver enable for half-duplex VL C2 operation. Each driver is enabled and disabled in less than 1.8V TO 5.5V 1µF BOOST 2µs, while each receiver remains continuously active. This C5* REGULATOR 220nF mode of operation is illustrated in Figures 15-17. VEE C3 1µF Battery Operation 2801 F06 *OMIT IF VL IS CONNECTED TO VCC To maximize battery life, connect V (and L1) directly to CC Figure 6. DC/DC Converter and Recommended Bypassing the unregulated battery voltage and V to the regulated L supply, as shown in Figure 22. This configuration typically V Logic Supply L minimizes conversion loss while providing compatibility A separate logic supply pin V allows the LTC2801 family to with system logic levels. L interface with any logic signal from 1.8V to 5.5V, as shown in Figure 7. Simply connect the desired logic supply to Inductor Selection VL. There is no interdependency between VCC and VL; they A 10µH inductor with a saturation current (ISAT) rating may simultaneously operate at any voltage from 1.8V to of at least 200mA and low DCR (copper wire resistance) 5.5V and sequence in any order. If VL is powered separately is recommended. Some small inductors meeting these from VCC, bypass VL with a 220nF capacitor (C5). requirements are listed in Table 3. 2801234fe 0

LTC2801/LTC2802/ LTC2803/LTC2804 aPPlicationS inForMation Table 3. Recommended Inductors flowing through inductor L1 and capacitors C1, C2. The peak inrush current must not exceed 2A. To avoid this PART I MAX DCR SIZE SAT NUMBER (mA) (Ω) (mm) MANUFACTURER condition, add a 1Ω resistor as shown in Figure 8. This LQH2MCN100K02L 225 1.2 2 × 1.6 × 0.95 Murata precaution is not relevant for supply voltages below 4.5V www.murata.com or rise times longer than 10µs. LBC2016T100K 245 0.85 2 × 1.6 × 1.6 Taiyo Yuden www.t-yuden.com Board Layout FSLB2520-100K 220 1.1 2.5 × 2 × 1.6 Toko www.tokoam.com The board layout should minimize the length and area of the SW and CAP traces. Suggested compact layouts for Capacitor Selection the LTC2801 family are shown in Figure 9 (a) and (b). The small size of ceramic capacitors makes them ideal for the LTC2801 family. X5R and X7R (preferred) types are recommended because their ESR is low and they retain their C1 GND capacitance over relatively wide voltage and temperature ranges. Use a voltage rating of at least 10V. GND C2 L1 Table 4. Recommended Ceramic Capacitor Manufacturers VL C5 MANUFACTURER URL GND VCC GND Murata www.murata.com TDK www.tdk.com C4 Taiyo Yuden www.t-yuden.com GND AVX www.avxcorp.com Kemet www.kemet.com TOP VIEW C3 = VIA Inrush Current and Supply Overshoot Precaution In certain applications, such as battery-operated and C1 GND wall-adapter devices, fast supply slew rates are generated when power is connected. If V ’s voltage is greater than CC GND 4.5V and its rise time is faster than 10µs, the pins VDD C2 L1 and SW can exceed their ABS MAX values during start- VL C5 GND up. When supply voltage is applied to VCC, the voltage VCC GND difference between V and V generates inrush current CC DD C4 L1 C1 4.5V TO 5.5V 10µH 220nF R1Ω1 CUINRRRUESNHT SW CAP GND 1/8W VCC C3 C4 1µF VDD GND C2 1µF TOP VIEW SCALE R1 WITH C1, C2, 1/C4 = VIA 2801 F08 2801 F09 Figure 8. Supply Overshoot Protection for Input Figure 9. Recommended Board Layouts for (a) Single and Supplies of 4.5V or Higher (b) Dual Transceiver Parts 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 tyPical aPPlicationS 1.8V TO 5.5V 5 5 VCC VCC 12 LTC2803 12 VL LTC2804 VL 1.8V TO 5.5V 11 10 PS MODE CELL PHONE 10 11 MODE RA ON PS VBATT PERIPHERAL 13 T2IN T2OUT 4 13 T2IN T2OUT 4 RTS RTS 14 T1IN T1OUT 3 14 T1IN T1OUT 3 TD TD 15 R2OUT R2IN 2 15 R2OUT R2IN 2 CTS CTS 16 R1OUT R1IN 1 16 R1OUT R1IN 1 RD RD GND GND 8 2801 F10 8 2801 F11 Figure 10. Power-Saving Receivers-Active Mode Figure 11. Cellphone Peripheral Interface 5V 3V 1.8V TO 5.5V 3 3 5 1.8V VCC 5V VCC VCC 10 LTC2801 10 LTC2802 12 LTC2804-1 VL VL VL 8 8 PS PS 9 9 11 MODE MODE OFF ON ON/OFF µP µP 13 T2IN T2OUT 4 11 TIN TOUT 2 11 TIN TOUT 2 14 T1IN T1OUT 3 15 R2OUT R2IN 2 12 ROUT RIN 1 12 ROUT RIN 1 16 R1OUT R1IN 1 GND GND GND 6 2801 F12 6 2801 F13 8 2801 F14 Figure 12. 1.8V Microprocessor Interface Figure 13. 5V Microprocessor Interface Figure 14. Power-Saving Shutdown Mode 1.8V TO 5.5V 1.8V TO 5.5V 1.8V TO 5.5V 3 3 5 VCC VCC VCC 10 LTC2802 10 LTC2802 12 LTC2803 VL VL VL 8 8 10 PS PS PS 9 9 11 R T MODE R T MODE R T MODE 13 T2IN T2OUT 4 11 TIN TOUT 2 11 TIN TOUT 2 3.3k 15 R2OUT R2IN 2 14 T1IN T1OUT 3 3.3k 12 ROUT RIN 1 12 ROUT RIN 1 3.3k 16 R1OUT R1IN 1 GND GND GND 6 2801 F15 6 2801 F16 8 2801 F17 Figure 15. Half-Duplex on Single Line, Figure 16. Half-Duplex on Single Line Figure 17. Half-Duplex Dual Transceiver Separate ROUT, TIN 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 tyPical aPPlicationS 2.5V TO 5.5V L1 10µH 5 7 5 7 VCC SW C1 VCC SW 13 4 C4 12 VL LTC2803 CAP 9 470nF 12 VL LTC2803 CAP 9 2µF 14 3 3k CL 13 T2IN T2OUT 4 13 T2IN T2OUT 4 2801 F18 14 T1IN T1OUT 3 14 T1IN T1OUT 3 DATA RATE 15 R2OUT R2IN 2 15 R2OUT R2IN 2 (kbps) CL (nF) LTC2803 LTC2804 100 5 X X 16 R1OUT R1IN 1 16 R1OUT R1IN 1 250 2 X X 1000 0.5 X GND VDD VEE GND VDD VEE 8 6 17 8 6 17 Figure 18. Driving Larger Loads 2801 F19 C2 C3 ANY COMBINATION 2µF 2µF LTC2801/LTC2802/LTC2803/LTC2804 Figure 19. Quad Transceiver (2.5V < V < 5.5V) CC 1.8V TO 5.5V C5 12 220nF VL LTC2803 VCC = 1.8V 3V TO 25V 2 R2IN R2OUT 15 VL DRIVERS DISABLED 1 R2IN R1OUT 16 –25V TO 0V 0V VCC = 1.8V DRIVERS LOADED VSW 11 10 5V/DIV OFF ON MODE PS VCC = 5.5V DRIVERS DISABLED 5 13 VCC T2IN 7 SW T1IN 14 VCC = 5.5V DRIVERS LOADED GND VDD VEE 200ns/DIV 8 6 17 2801 F21 Figure 21. Typical SW Pin Waveforms NOTES: 2801 F20 1. NO L1 OR C2-C4 NEEDED. 2. RECEIVERS ACTIVE MODE SHOWN HAS NO DC HYSTERESIS. 3. SEE DUTY CYCLE GRAPH IN TYPICAL PERFORMANCE SECTION. Figure 20. 100kbps Dual Inverting Level Translator (I = 15µA Static) L 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 PackaGe deScriPtion DE/UE Package 12-Lead Plastic DFN (4mm × 3mm) (Reference LTC DWG # 05-08-1695 Rev D) 0.70(cid:112)0.05 3.30(cid:112)0.05 3.60(cid:112)0.05 2.20(cid:112)0.05 1.70(cid:112) 0.05 PACKAGE OUTLINE 0.25(cid:112) 0.05 0.50 BSC 2.50 REF RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 4.00(cid:112)0.10 R = 0.115 0.40(cid:112) 0.10 (2 SIDES) TYP 7 12 R = 0.05 TYP 3.30(cid:112)0.10 3.00(cid:112)0.10 (2 SIDES) 1.70(cid:112) 0.10 PIN 1 PIN 1 NOTCH TOP MARK R = 0.20 OR (NOTE 6) 0.35(cid:115) 45(cid:111) CHAMFER 6 1 (UE12/DE12) DFN 0806 REV D 0.200 REF 0.75(cid:112)0.05 0.25(cid:112) 0.05 0.50 BSC 2.50 REF 0.00 – 0.05 BOTTOM VIEW—EXPOSED PAD NOTE: 1. DRAWING PROPOSED TO BE A VARIATION OF VERSION (WGED) IN JEDEC PACKAGE OUTLINE M0-229 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 PackaGe deScriPtion DHC Package 16-Lead Plastic DFN (5mm × 3mm) (Reference LTC DWG # 05-08-1706) 0.65 ±0.05 3.50 ±0.05 1.65 ±0.05 2.20 ±0.05 (2 SIDES) PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 4.40 ±0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 5.00 ±0.10 R = 0.115 0.40 ± 0.10 TYP (2 SIDES) 9 16 R = 0.20 TYP 3.00 ±0.10 1.65 ± 0.10 (2 SIDES) (2 SIDES) PIN 1 PIN 1 TOP MARK NOTCH (SEE NOTE 6) (DHC16) DFN 1103 8 1 0.200 REF 0.75 ±0.05 0.25 ± 0.05 0.50 BSC 4.40 ±0.10 (2 SIDES) 0.00 – 0.05 BOTTOM VIEW—EXPOSED PAD NOTE: 1. DRAWING PROPOSED TO BE MADE VARIATION OF VERSION (WJED-1) IN JEDEC PACKAGE OUTLINE MO-229 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 PackaGe deScriPtion GN Package 16-Lead Plastic SSOP (Narrow .150 Inch) (Reference LTC DWG # 05-08-1641) .189 – .196* .045 ±.005 (4.801 – 4.978) .009 (0.229) 16 15 14 13 12 11 109 REF .254 MIN .150 – .165 .229 – .244 .150 – .157** (5.817 – 6.198) (3.810 – 3.988) .0165 ±.0015 .0250 BSC RECOMMENDED SOLDER PAD LAYOUT 1 2 3 4 5 6 7 8 .015 ± .004 × 45° .0532 – .0688 .004 – .0098 (0.38 ± 0.10) (1.35 – 1.75) (0.102 – 0.249) .007 – .0098 0° – 8° TYP (0.178 – 0.249) .016 – .050 .008 – .012 .0250 GN16 (SSOP) 0204 (0.406 – 1.270) (0.203 – 0.305) (0.635) NOTE: TYP BSC 1. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) 3. DRAWING NOT TO SCALE *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 2801234fe 

LTC2801/LTC2802/ LTC2803/LTC2804 reviSion hiStory (Revision history begins at Rev E) REV DATE DESCRIPTION PAGE NUMBER E 5/10 Replaced Product Selection Guide 1 Labeled packages with appropriate part numbers in Pin Configuration section 2 Changed title of Table 1 in Mode Control section 8 Updated Feature Summary section 9 Revised first sentence of Power Saving Modes section 10 2801234fe Information furnished by Linear Technology Corporation is believed to be accurate and reliable.  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.

LTC2801/LTC2802/ LTC2803/LTC2804 tyPical aPPlication L1 C1 10µH 220nF 1.8V TO 5.5V + C4 1µF – * 7 9 DC-DC 5 SW CAP VCC 1.8V TO 5.5V 12 VL LTC2804 C5 * 220nF 10 PS VCC 11 PPX MODE 13 T2IN T2OUT 4 PPY CTS 14 T1IN T1OUT 3 TXD RX µP UART 15 R2OUT R2IN 2 PPZ RTS 16 R1OUT R1IN 1 RXD TX GND VDD VEE 8 6 17 2801 F22 C2 C3 1µF 1µF *ADDITIONAL BYPASS CAPACITOR AS NEEDED Figure 22. Diagnostic Port Operating Directly Off Unregulated Battery Voltage related PartS PART NUMBER DESCRIPTION COMMENTS LT1780/LT1781 2-Driver/2-Receiver RS232 Transceiver Single 5V Supply with 0.1μF Capacitors, 15kV ESD LTC1337 3-Driver/5-Receiver RS232 Transceiver Ultralow Power for DTE Applications LTC1338 5-Driver/3-Receiver RS232 Transceiver Ultralow Power for DCE Applications LT1039/LT1039-16 3-Driver/3-Receiver RS232 Transceiver 30kΩ Input Impedance for Multidrop Applications LTC1348 3-Driver/5-Receiver RS232 Transceiver True RS232 Levels on 3.3V Supply 2801234fe  Linear Technology Corporation LT 0510 REV E • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 l FAX: (408) 434-0507 l www.linear.com  LINEAR TECHNOLOGY CORPORATION 2005

Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: A nalog Devices Inc.: LTC2804CDHC#PBF LTC2803IDHC#TR LTC2803CDHC#PBF LTC2803CGN-1#TRPBF LTC2804CGN-1#TR LTC2804CGN-1#PBF LTC2801CDE#TRPBF LTC2804IGN-1#TR LTC2802CDE LTC2803CDHC#TR LTC2804IDHC#PBF LTC2801IDE#TRPBF LTC2803IGN-1 LTC2802CDE#PBF LTC2802IDE LTC2803IDHC#PBF LTC2803IGN-1#PBF LTC2804CGN-1#TRPBF LTC2802IDE#PBF LTC2804CDHC#TR LTC2803IDHC LTC2801IDE#TR LTC2803CGN-1#TR LTC2804IDHC#TRPBF LTC2803IDHC#TRPBF LTC2802CDE#TRPBF LTC2804IGN-1 LTC2804IGN-1#PBF LTC2803IGN-1#TRPBF LTC2802IDE#TRPBF LTC2801CDE#TR LTC2804IDHC LTC2803CDHC#TRPBF LTC2801CDE LTC2803IGN-1#TR LTC2803CDHC LTC2801CDE#PBF LTC2804CGN-1 LTC2802IDE#TR LTC2801IDE LTC2804CDHC LTC2803CGN-1#PBF LTC2801IDE#PBF LTC2804IDHC#TR LTC2804CDHC#TRPBF LTC2804IGN-1#TRPBF LTC2802CDE#TR LTC2803CGN-1