LTC1382 5V Low Power RS232 Transceiver with Shutdown U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LTC®1382 is an ultra-low power 2-driver/2-receiver RS232 transceiver that operates from a single 5V supply. The charge pump requires only four spacesaving 0.1µF capacitors. Operates from a Single 5V Supply Low Supply Current: ICC = 220µA ICC = 0.2µA in Shutdown Mode ESD Protection Over ±10kV Uses Small Capacitors: 0.1µF Operates to 120kBaud Output Overvoltage Does Not Force Current Back into Supplies RS232 I/O Lines Can Be Forced to ±25V Without Damage Pin Compatible with LT1180A The transceiver operates in one of two modes, Normal and Shutdown. In the Normal mode, ICC is only 220µA with the driver outputs unloaded. In the Shutdown mode, the charge pump is turned off, the driver outputs are forced into three-state, both receivers are off and ICC drops to 0.2µA. The LTC1382 is fully compliant with all data rate and overvoltage RS232 specifications. The transceiver can operate up to 120kbaud with a 2500pF, 3kΩ load. Both driver outputs and receiver inputs can be forced to ±25V without damage and can survive multiple ±10kV ESD strikes. U APPLICATIO S ■ ■ Notebook Computers Palmtop Computers , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO 2-Drivers/2-Receivers with Shutdown 2 17 4 3 5 LOGIC INPUT 6 0.1µF 0.1µF 12 15 232 OUTPUT VCC 300k LOGIC INPUT LOGIC OUTPUT LOGIC OUTPUT ON/OFF 11 8 13 14 5k 10 18 9 5k 16 1.2 TEST CONDITION: VCC = 5V 7 VCC 300k 600 232 OUTPUT 232 INPUT 232 INPUT 500 1.0 400 0.8 300 0.6 QUIESCENT CURRENT 200 0.4 SHUTDOWN CURRENT 100 0 –20 0 20 40 TEMPERATURE (°C) SHUTDOWN CURRENT (µA) 0.1µF LTC1382 VCC = 5V QUIESCENT CURRENT (µA) 0.1µF Quiescent and Shutdown Supply Current vs Temperature 0.2 60 80 0 LTC1382 • TA02 LTC1382 • TA01 1382fa 1 LTC1382 W W W AXI U U ABSOLUTE RATI GS Supply Voltage (VCC) ................................................ 6V Input Voltage Driver ....................................... – 0.3V to V CC + 0.3V Receiver ............................................... – 25V to 25V Digital Input ............................... – 0.3V to VCC + 0.3V Output Voltage Driver .................................................... – 25V to 25V Receiver .................................... – 0.3V to VCC + 0.3V Short-Circuit Duration V + ................................................................... 30 sec V – ................................................................... 30 sec Driver Output .............................................. Indefinite Receiver Output .......................................... Indefinite Operating Temperature Range LTC1382C ............................................... 0°C to 70°C LTC1382I ............................................ – 40°C to 85°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C U U W PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER TOP VIEW NC 1 18 ON/OFF C1+ 2 17 VCC + 16 GND V 3 C1– 4 15 TR1 OUT C2+ 5 14 RX1 IN C2– 6 13 RX1 OUT V– 7 12 TR1 IN TR2 OUT 8 11 TR2 IN RX2 IN 9 N PACKAGE 18-LEAD PDIP LTC1382CN LTC1382CSW LTC1382IN LTC1382ISW 10 RX2 OUT SW PACKAGE 18-LEAD PLASTIC SO TJMAX = 125°C, θJA = 65°C/W (N) TJMAX = 125°C, θJA = 85°C/W (S) Consult LTC Marketing for parts specified with wider operating temperature ranges. DC ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range. VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, VON/OFF = VCC, unless otherwise noted. PARAMETER CONDITIONS Any Driver Output Voltage Swing 3k to GND Logic Input Voltage Level Logic Input Current Output Short-Circuit Current Output Leakage Current Any Receiver Input Voltage Thresholds Hysteresis Input Resistance Output Voltage Output Short-Circuit Current Output Leakage Current MIN TYP ● ● 5.0 – 5.0 Input Low Level (VOUT = High) Input High Level (VOUT = Low) VIN = VCC VIN = 0V VOUT = 0V Shutdown or VCC = 0V (Note 3), VOUT = ±10V ● ● 2.0 7.0 – 6.5 1.4 1.4 Input Low Threshold Input High Threshold ● ● 0.8 ● 0.1 3 – 10V ≤ VIN ≤ 10V Output Low, IOUT = – 1.6mA (VCC = 5V) Output High, IOUT = 160µA (VCC = 5V) Sinking Current, VOUT = VCC Sourcing Current VOUT = 0V Shutdown (Note 3), 0V ≤ VOUT ≤ VCC Positive Negative ● ● ±9 ● ● ● ● 3.0 – 15 10 – 20 ±12 ±10 1.3 1.7 0.4 5 0.2 3.2 – 40 20 1 MAX 0.8 5 – 40 ±500 2.4 1 7 0.4 10 UNITS V V V V µA µA mA µA V V V kΩ V V mA mA µA 1382fa 2 LTC1382 DC ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range. VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, VON/OFF = VCC, unless otherwise noted. PARAMETER Power Supply Generator V + Output Voltage CONDITIONS MIN IOUT = 0mA IOUT = 8mA IOUT = 0mA IOUT = – 8mA Shutdown to Turn-On V – Output Voltage Supply Rise Time Power Supply VCC Supply Current MAX UNITS 8.0 7.5 – 8.0 – 7.0 0.2 No Load (Note 2), 0°C to 70°C No Load (Note 2), – 40°C to 85°C Shutdown (Note 3) Supply Leakage Current (VCC) Digital Input Threshold Low Digital Input Threshold High TYP ● ● ● ● 2.0 ● 0.22 0.35 0.2 1.4 1.4 V V V V ms 0.5 1.0 10 0.8 mA mA µA V V AC CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range. VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, unless otherwise noted. PARAMETER Slew Rate CONDITIONS RL = 3k, CL = 51pF RL = 3k, CL = 2500pF t HLD (Figure 1) t LHD (Figure 1) t HLR (Figure 2) t LHR (Figure 2) Driver Propagation Delay (TTL to RS232) Receiver Propagation Delay (RS232 to TTL) MIN 3 ● ● ● ● Note 1: Absolute Maximum Ratings are those values beyond which the life of the device may be impaired. Note 2: Supply current is measured with driver and receiver outputs unloaded. TYP 8 5 2 2 0.3 0.3 MAX 30 UNITS V/µs V/µs µs µs µs µs 3.5 3.5 0.8 0.8 Note 3: Measurements made in the Shutdown mode are performed with VON/OFF = 0V. U W TYPICAL PERFOR A CE CHARACTERISTICS Driver Output Voltage vs Temperature DRIVER OUTPUT VOLTAGE (V) 6 OUTPUT HIGH VCC = 5V 2.0 VCC = 4.5V 4 2 0 –2 OUTPUT LOW VCC = 4.5V –4 –6 VTH 1.8 1.6 VTL 1.4 1.0 20 30 40 50 TEMPERATURE (°C) 30 25 20 15 10 5 –8 10 35 1.2 VCC = 5V 0 VCC = 5V RL = 3k CL = 2500pF 2 DRIVERS ACTIVE 40 SUPPLY CURRENT (mA) RL = 3k 8 Supply Current vs Data Rate 45 2.2 THRESHOLD VOLTAGE (V) 10 Receiver Input Thresholds vs Temperature 60 70 LTC1382 • TPC01 0 0 10 40 30 50 20 TEMPERATURE (˚C) 60 70 LTC1382 • TPC02 0 25 50 75 100 125 DATA RATE (kBAUD) 150 175 LTC1382 • TPC03 1382fa 3 LTC1382 U W TYPICAL PERFOR A CE CHARACTERISTICS Driver Short-Circuit Current vs Temperature 18 16 16 14 12 2 DRIVERS LOADED RL = 3k 10 8 1 DRIVER LOADED RL = 3k 6 4 2 Receiver Short-Circuit Current vs Temperature 50 SHORT-CIRCUIT CURRENT (mA) 18 SHORT-CIRCUIT CURRENT (mA) SUPPLY CURRENT (mA) VCC Supply Current vs Temperature – 14 ISC 12 ISC+ 10 8 6 4 40 ISC– 30 20 ISC+ 2 0 10 0 0 10 20 30 40 50 TEMPERATURE (°C) 60 70 0 10 20 30 40 50 TEMPERATURE (°C) LTC1382 • TPC04 60 0 70 30 20 50 40 TEMPERATURE (°C) 60 70 LTC1382 • TPC06 LTC1382 • TPC05 Driver Leakage in Shutdown vs Temperature 10 Driver Output Waveforms Receiver Output Waveforms 45 DRIVER OUTPUT RL = 3k CL = 2500pF LEAKAGE CURRENT (µA) 40 35 30 25 RECEIVER OUTPUT CL = 51pF DRIVER OUTPUT RL = 3k VOUT = –20V INPUT 20 INPUT 15 10 VOUT = 20V 5 LTC1382 • TPC08 LTC1382 • TPC09 0 0 10 30 20 40 50 TEMPERATURE (°C) 60 70 LTC1349 • TPC05 1382fa 4 LTC1382 U U U PI FU CTIO S VCC: 5V Input Supply Pin. This pin should be decoupled with a 0.1µF ceramic capacitor. charge pump efficiency, the capacitor’s effective series resistance should be less than 2Ω. GND: Ground Pin. TR IN: RS232 Driver Input Pins. Inputs are TTL/CMOS compatible. The inputs of unused drivers can be left unconnected since 300k input pull-up resistors to VCC are included on chip. To minimize power consumption, the internal driver pull-up resistors are disconnected from VCC in the Shutdown mode. ON/OFF: TTL/CMOS Compatible Shutdown Pin. A logic low puts the device in the Shutdown mode. Both driver outputs are forced into three-state and the supply current is 0.2µA. V +: Positive Supply Output (RS232 Drivers). V + ≅ 2VCC – 2V. This pin requires an external capacitor C = 0.1µF for charge storage. The capacitor may be tied to ground or VCC. With multiple devices, the V + and V – pins may share a common capacitor. For large numbers of devices, increasing the size of the shared common storage capacitors is recommended to reduce ripple. V –: Negative Supply Output (RS232 Drivers). V – ≅ – (2VCC – 2V). This pin requires an external capacitor C = 0.1µF for charge storage. C1+, C1–, C2+, C2–: Commutating Capacitor Inputs. These pins require two external capacitors C = 0.1µF: one from C1+ to C1– and another from C2+ to C2 –. To maintain TR OUT: Driver Outputs at RS232 Voltage Levels. Outputs are in a high impedance state when in the Shutdown or VCC = 0V. The driver outputs are protected against ESD to ±10kV for human body model discharges. RX IN: Receiver Inputs. These pins can be forced to ±25V without damage. The receiver inputs are protected against ESD to ±10kV for human body model discharges. Each receiver provides 0.4V of hysteresis for noise immunity. RX OUT: Receiver Outputs with TTL/CMOS Voltage Levels. Outputs are in a high impedance state when in the Shutdown mode. U W W SWITCHI G TI E WAVEFOR S DRIVER INPUT VCC 1.4V 1.4V 0V V+ DRIVER OUTPUT 0V 0V t LHD V– 1.7V RX INPUT RX OUTPUT 0V 2.4V 0.8V t LHR t HLD VCC 1.3V t HLR LTC1382 • F01 Figure 1. Driver Propagation Delay Timing VCC 0V LTC1382 • F02 Figure 2. Receiver Propagation Delay Timing 1382fa 5 LTC1382 TEST CIRCUITS Receiver Timing Test Load Driver Timing Test Load DRIVER INPUT DRIVER OUTPUT RX OUTPUT RX INPUT DRIVER 51pF RX 3k 51pF LTC1382 • TA04 LTC1382 • TA03 ESD Test Circuit 0.1µF 2 17 4 3 5 0.1µF LOGIC INPUT 6 LTC1382 VCC = 5V 0.1µF 7 0.1µF VCC 300k 12 15 232 OUTPUT VCC 300k LOGIC INPUT LOGIC OUTPUT LOGIC OUTPUT ON/OFF 11 8 13 14 5k 10 18 9 5k 232 OUTPUT 232 INPUT RS232 LINE PINS PROTECTED TO ±10kV 232 INPUT 16 LTC1382 • TA05 1382fa 6 LTC1382 U PACKAGE DESCRIPTIO N Package 18-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .900* (22.860) MAX 18 17 16 15 14 13 12 11 10 1 2 3 4 5 6 7 8 9 .255 ± .015* (6.477 ± 0.381) .300 – .325 (7.620 – 8.255) .130 ± .005 (3.302 ± 0.127) .020 (0.508) MIN .009 – .015 (0.229 – 0.381) .065 (1.651) TYP +.035 .325 –.015 ( 8.255 +0.889 –0.381 .045 – .065 (1.143 – 1.651) .125 (3.175) MIN ) .005 (0.127) MIN .018 ± .003 (0.457 ± 0.076) .100 (2.54) BSC NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) N18 0502 SW Package 18-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .030 ±.005 TYP .447 – .463 (11.354 – 11.760) NOTE 4 N 18 17 16 15 14 13 12 11 10 N .325 ±.005 .420 MIN .394 – .419 (10.007 – 10.643) NOTE 3 1 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) .005 (0.127) RAD MIN 1 2 3 4 5 6 7 .093 – .104 (2.362 – 2.642) 8 9 .037 – .045 (0.940 – 1.143) 0° – 8° TYP .009 – .013 (0.229 – 0.330) NOTE: 1. DIMENSIONS IN NOTE 3 .016 – .050 (0.406 – 1.270) .050 (1.270) BSC .004 – .012 (0.102 – 0.305) .014 – .019 (0.356 – 0.482) TYP INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) S18 (WIDE) 0502 1382fa 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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 7 LTC1382 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1780/LT1781 5V, 2 Driver, 2 Receiver RS232 Transeivers ±15kV ESD per IEC 1000-4 LTC1383 5V, 2 Driver, 2 Receiver RS232 Transceiver 220µA Supply Current, Narrow 16-pin SO LTC1384 5V, 2 Driver, 2 Receiver RS232 Transceiver 220µA Supply Current, 2 Receivers Active in Shutdown LTC1385 3.3V, 2 Driver, 2 Receiver RS562 Transceiver 220µA Supply Current, 2 Receivers Active in Shutdown LTC1386 3.3V, 2 Driver, 2 Receiver RS562 Transceiver 220µA Supply Current, Narrow 16-pin SO 1382fa 8 Linear Technology Corporation LW/TP 1002 1K REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 ● FAX: (408) 434-0507 ● linear.com LINEAR TECHNOLOGY CORPORATION 1994