LTC1382_1

LTC1382 5V Low Power RS232 Transceiver with Shutdown FEATURES ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO ■ ■ 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 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. 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. , LTC and LT are registered trademarks of Linear Technology Corporation. APPLICATIO S ■ ■ Notebook Computers Palmtop Computers TYPICAL APPLICATIO 2-Drivers/2-Receivers with Shutdown 2 0.1µF 4 5 0.1µF 6 12 VCC 300k LOGIC INPUT LOGIC OUTPUT 11 13 5k 8 14 232 OUTPUT 232 INPUT LTC1382 VCC 300k 15 17 3 7 0.1µF 0.1µF VCC = 5V Quiescent and Shutdown Supply Current vs Temperature 600 TEST CONDITION: VCC = 5V 500 1.0 1.2 QUIESCENT CURRENT (µA) 400 300 200 100 0 –20 SHUTDOWN CURRENT QUIESCENT CURRENT LOGIC INPUT 232 OUTPUT LOGIC OUTPUT ON/OFF 10 18 5k 9 16 232 INPUT 0 LTC1382 • TA01 U SHUTDOWN CURRENT (µA) 0.8 0.6 0.4 0.2 0 20 40 TEMPERATURE (°C) 60 80 LTC1382 • TA02 U U 1382fa 1 LTC1382 ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO TOP VIEW NC 1 C1+ 2 V + 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 18 ON/OFF 17 VCC 16 GND 15 TR1 OUT 14 RX1 IN 13 RX1 OUT 12 TR1 IN 11 TR2 IN 10 RX2 OUT SW PACKAGE 18-LEAD PLASTIC SO ORDER PART NUMBER LTC1382CN LTC1382CSW LTC1382IN LTC1382ISW 3 C1– 4 C2+ 5 C2– 6 V– 7 TR2 OUT 8 RX2 IN 9 N PACKAGE 18-LEAD PDIP 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 PARAMETER Any Driver Output Voltage Swing 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 CONDITIONS 3k to GND 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. MIN Positive Negative ● ● ● ● ● ● TYP 7.0 – 6.5 1.4 1.4 – 20 ±12 ± 10 1.3 1.7 0.4 5 0.2 3.2 – 40 20 1 MAX UNITS V V V V µA µA mA µA V V V kΩ V V mA mA µA 5.0 – 5.0 2.0 Input Low Level (VOUT = High) Input High Level (VOUT = Low) VIN = VCC VIN = 0V VOUT = 0V Shutdown or VCC = 0V (Note 3), VOUT = ± 10V Input Low Threshold Input High Threshold – 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 0.8 5 – 40 ± 500 ±9 ● ● ● ● ● ● 0.8 0.1 3 3.0 – 15 10 2.4 1 7 0.4 ● 10 1382fa 2 U W U U WW W LTC1382 DC ELECTRICAL CHARACTERISTICS PARAMETER Power Supply Generator V + Output Voltage V – Output Voltage Supply Rise Time Power Supply VCC Supply Current Supply Leakage Current (VCC) Digital Input Threshold Low Digital Input Threshold High CONDITIONS IOUT = 0mA IOUT = 8mA IOUT = 0mA IOUT = – 8mA Shutdown to Turn-On 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. MIN TYP 8.0 7.5 – 8.0 – 7.0 0.2 ● ● ● ● ● MAX UNITS V V V V ms No Load (Note 2), 0°C to 70°C No Load (Note 2), – 40°C to 85°C Shutdown (Note 3) 2.0 0.22 0.35 0.2 1.4 1.4 0.5 1.0 10 0.8 mA mA µA V V AC CHARACTERISTICS PARAMETER Slew Rate Driver Propagation Delay (TTL to RS232) Receiver Propagation Delay (RS232 to TTL) The ● denotes specifications which apply over the full operating temperature range. VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, unless otherwise noted. 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) MIN 3 ● ● ● ● TYP 8 5 2 2 0.3 0.3 MAX 30 3.5 3.5 0.8 0.8 UNITS V/µs V/µs µs µs µs µs 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. Note 3: Measurements made in the Shutdown mode are performed with VON/OFF = 0V. TYPICAL PERFOR A CE CHARACTERISTICS Driver Output Voltage vs Temperature 10 8 RL = 3k OUTPUT HIGH VCC = 5V THRESHOLD VOLTAGE (V) DRIVER OUTPUT VOLTAGE (V) 4 2 0 –2 –4 –6 –8 0 10 20 30 40 50 TEMPERATURE (°C) 60 70 OUTPUT LOW VCC = 4.5V VCC = 5V SUPPLY CURRENT (mA) 6 VCC = 4.5V LTC1382 • TPC01 UW Receiver Input Thresholds vs Temperature 2.2 2.0 VTH 1.8 1.6 1.4 1.2 5 35 30 25 20 15 10 45 40 Supply Current vs Data Rate VCC = 5V RL = 3k CL = 2500pF 2 DRIVERS ACTIVE VTL 1.0 0 10 40 30 50 20 TEMPERATURE (˚C) 60 70 0 0 25 50 75 100 125 DATA RATE (kBAUD) 150 175 LTC1382 • TPC02 LTC1382 • TPC03 1382fa 3 LTC1382 TYPICAL PERFOR A CE CHARACTERISTICS VCC Supply Current vs Temperature 18 16 SHORT-CIRCUIT CURRENT (mA) SUPPLY CURRENT (mA) 14 12 10 8 6 4 2 0 0 10 20 30 40 50 TEMPERATURE (°C) 60 70 1 DRIVER LOADED RL = 3k 2 DRIVERS LOADED RL = 3k 14 12 10 8 6 4 2 0 0 ISC – SHORT-CIRCUIT CURRENT (mA) LTC1382 • TPC04 Driver Leakage in Shutdown vs Temperature 45 40 LEAKAGE CURRENT (µA) 35 30 25 20 15 10 5 0 0 10 30 20 40 50 TEMPERATURE (°C) 60 70 VOUT = 20V VOUT = – 20V LTC1349 • TPC05 4 UW Driver Short-Circuit Current vs Temperature 18 16 50 Receiver Short-Circuit Current vs Temperature ISC+ 40 ISC– 30 20 ISC+ 10 10 20 30 40 50 TEMPERATURE (°C) 60 70 0 10 30 20 50 40 TEMPERATURE (°C) 60 70 LTC1382 • TPC05 LTC1382 • TPC06 Driver Output Waveforms DRIVER OUTPUT RL = 3k CL = 2500pF DRIVER OUTPUT RL = 3k INPUT Receiver Output Waveforms RECEIVER OUTPUT CL = 51pF INPUT LTC1382 • TPC08 LTC1382 • TPC09 1382fa LTC1382 PI FU CTIO S VCC: 5V Input Supply Pin. This pin should be decoupled with a 0.1µF ceramic capacitor. GND: Ground Pin. 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 charge pump efficiency, the capacitor’s effective series resistance should be less than 2Ω. 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. 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. SWITCHI G TI E WAVEFOR S DRIVER INPUT DRIVER OUTPUT t LHD VCC 1.4V 1.4V 0V V+ 0V t HLD LTC1382 • F01 Figure 1. Driver Propagation Delay Timing W W U U U U RX INPUT RX OUTPUT t LHR 1.7V VCC 1.3V 0V 2.4V VCC 0V LTC1382 • F02 0V V– 0.8V t HLR Figure 2. Receiver Propagation Delay Timing 1382fa 5 LTC1382 TEST CIRCUITS Driver Timing Test Load DRIVER OUTPUT DRIVER 51pF 3k Receiver Timing Test Load RX OUTPUT RX INPUT RX 51pF DRIVER INPUT LTC1382 • TA03 LTC1382 • TA04 ESD Test Circuit 2 0.1µF 4 5 0.1µF 6 12 VCC 300k LOGIC INPUT LOGIC OUTPUT 11 13 5k 8 14 232 OUTPUT 232 INPUT RS232 LINE PINS PROTECTED TO ±10kV LTC1382 VCC 300k 15 17 3 7 0.1µF 0.1µF VCC = 5V LOGIC INPUT 232 OUTPUT LOGIC OUTPUT ON/OFF 10 18 5k 9 16 232 INPUT LTC1382 • TA05 1382fa 6 LTC1382 PACKAGE DESCRIPTIO .300 – .325 (7.620 – 8.255) .009 – .015 (0.229 – 0.381) +.035 .325 –.015 ( 8.255 +0.889 –0.381 ) INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) NOTE: 1. DIMENSIONS ARE .030 ±.005 TYP N .420 MIN 1 2 3 RECOMMENDED SOLDER PAD LAYOUT .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) 0° – 8° TYP .005 (0.127) RAD MIN .009 – .013 (0.229 – 0.330) NOTE: 1. DIMENSIONS IN NOTE 3 .016 – .050 (0.406 – 1.270) 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) 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. U 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 .255 ± .015* (6.477 ± 0.381) 1 .130 ± .005 (3.302 ± 0.127) .020 (0.508) MIN 2 3 4 5 6 7 8 9 .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .125 (3.175) MIN .005 (0.127) MIN .018 ± .003 (0.457 ± 0.076) .100 (2.54) BSC N18 0502 SW Package 18-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .447 – .463 (11.354 – 11.760) NOTE 4 18 17 16 15 14 13 12 11 10 N .325 ±.005 NOTE 3 .394 – .419 (10.007 – 10.643) N/2 N/2 1 .093 – .104 (2.362 – 2.642) 2 3 4 5 6 7 8 9 .037 – .045 (0.940 – 1.143) .050 (1.270) BSC .004 – .012 (0.102 – 0.305) .014 – .019 (0.356 – 0.482) TYP S18 (WIDE) 0502 1382fa 7 LTC1382 RELATED PARTS PART NUMBER LT1780/LT1781 LTC1383 LTC1384 LTC1385 LTC1386 DESCRIPTION 5V, 2 Driver, 2 Receiver RS232 Transeivers 5V, 2 Driver, 2 Receiver RS232 Transceiver 5V, 2 Driver, 2 Receiver RS232 Transceiver 3.3V, 2 Driver, 2 Receiver RS562 Transceiver 3.3V, 2 Driver, 2 Receiver RS562 Transceiver COMMENTS ± 15kV ESD per IEC 1000-4 220µA Supply Current, Narrow 16-pin SO 220µA Supply Current, 2 Receivers Active in Shutdown 220µA Supply Current, 2 Receivers Active in Shutdown 220µA Supply Current, Narrow 16-pin SO 1382fa 8 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 ● FAX: (408) 434-0507 ● linear.com LW/TP 1002 1K REV A • PRINTED IN USA  LINEAR TECHNOLOGY CORPORATION 1994