LTC1384 5V Low Power RS232 Transceiver with 2 Receivers Active in Shutdown U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LTC®1384 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 = 35µA in Shutdown Mode with Both Receivers Kept Alive 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 kept active and ICC drops to 35µA. The receiver outputs may be forced into three-state at any time using the receiver enable (RX EN) pin. U APPLICATIO S ■ ■ The LTC1384 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. Notebook Computers Palmtop Computers , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO Quiescent and Shutdown Supply Current vs Temperature 2-Drivers/2-Receivers with Shutdown and Receiver Enable 2 LOGIC INPUT 6 1000 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 18 5k 1 RX EN SHUTDOWN CURRENT 800 40 600 30 400 20 QUIESCENT CURRENT 200 10 232 INPUT 0 –20 9 10 232 OUTPUT 50 SHUTDOWN CURRENT (µA) 0.1µF LTC1384 60 TEST CONDITION: VCC = 5V 3 4 5 1200 VCC = 5V QUIESCENT CURRENT (µA) 0.1µF 17 232 INPUT 0 20 40 TEMPERATURE (°C) 60 80 0 LTC1384 • TA02 16 LTC1384 • TA01 1384fa 1 LTC1384 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 LTC1384C ............................................... 0°C to 70°C LTC1384I ............................................ – 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 TOP VIEW RX EN 1 20 ON/OFF C1 + 2 19 VCC V+ 3 18 GND C1 – 4 17 TR1 OUT C2 + 5 16 RX1 IN C2 – 6 ORDER PART NUMBER RX EN 1 LTC1384CG LTC1384IG 18 ON/OFF C1+ 2 17 VCC V+ 3 16 GND C1– 4 15 TR1 OUT 15 RX1 OUT C2+ 5 14 RX1 IN 13 RX1 OUT – 7 14 TR1 IN C2– 6 TR2 OUT 8 13 TR2 IN V– 7 12 TR1 IN RX2 IN 9 12 RX2 OUT TR2 OUT 8 11 TR2 IN V NC 10 11 NC G PACKAGE 20-LEAD SSOP TJMAX = 125°C, θJA = 135°C/W ORDER PART NUMBER TOP VIEW LTC1384CN LTC1384CSW LTC1384IN LTC1384ISW RX2 IN 9 10 RX2 OUT N PACKAGE 18-LEAD PDIP SW PACKAGE 18-LEAD PLASTIC SO TJMAX = 125°C, θJA = 65°C/W TJMAX = 125°C, θJA = 85°C/W 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, RX EN = 0V, 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 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) Positive Negative ● ● ±9 ● ● ● 3.0 – 20 ±12 ±10 1.3 1.7 0.4 5 0.2 3.2 MAX 0.8 5 – 40 ±500 2.4 1 7 0.4 UNITS V V V V µA µA mA µA V V V kΩ V V 1384fa 2 LTC1384 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, RX EN = 0V, unless otherwise noted. PARAMETER Output Short-Circuit Current CONDITIONS Sinking Current, VOUT = VCC Sourcing Current, VOUT = 0V EN = VCC, 0V ≤ VOUT ≤ VCC Output Leakage Current Power Supply Generator V + Output Voltage MIN – 15 10 ● 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 mA mA µA 10 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 – 40 20 1 ● ● ● ● 2.0 ● 0.22 0.35 35 1.4 1.4 V V V V ms 0.5 1.0 50 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 Receiver Input Thresholds vs Temperature Driver Output Voltage vs Temperature VCC = 5V RL = 3k CL = 2500pF 2 DRIVERS ACTIVE 40 2.0 VCC = 4.5V 4 2 0 –2 OUTPUT LOW VCC = 4.5V –4 45 VTH SUPPLY CURRENT (mA) 6 OUTPUT HIGH VCC = 5V THRESHOLD VOLTAGE (V) RL = 3k 8 DRIVER OUTPUT VOLTAGE (V) Supply Current vs Data Rate 2.2 10 1.8 1.6 VTL 1.4 35 30 25 20 15 10 1.2 5 –6 VCC = 5V 1.0 –8 0 10 20 30 40 50 TEMPERATURE (°C) 60 70 0 10 40 30 50 20 TEMPERATURE (˚C) 60 70 0 0 25 50 75 100 125 DATA RATE (kBAUD) 150 175 1384fa 3 LTC1384 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 14 ISC– 12 ISC+ SHORT-CIRCUIT CURRENT (mA) 18 SHORT-CIRCUIT CURRENT (mA) SUPPLY CURRENT (mA) VCC Supply Current vs Temperature 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) LTC1384 • TPC04 60 0 70 10 30 20 50 40 TEMPERATURE (°C) 70 LTC1384 • TPC06 LTC1384 • TPC05 Driver Leakage in Shutdown vs Temperature 60 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 20 INPUT INPUT 15 10 VOUT = 20V 5 LTC1384 • TPC09 LTC1384 • TPC08 5µs/DIV 5µs/DIV 0 0 10 30 20 40 50 TEMPERATURE (°C) 60 70 LTC1384 • TPC07 1384fa 4 LTC1384 U U U 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 independent of the RX EN pin. The supply current of the device drops to 35µA (two receivers alive) and both driver outputs are forced into three-state. RX EN: TTL/CMOS Compatible Receiver Enable Pin. A logic high forces the receiver outputs into three-state. A logic low enables the receiver outputs. 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. A logic high at RX EN puts the outputs into three-state. 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 – t HLD VCC 1.7V RX INPUT RX OUTPUT 1.3V 0V 2.4V 0.8V t LHR t HLR LTC1384 • F01 Figure 1. Driver Propagation Delay Timing VCC 0V LTC1384 • F02 Figure 2. Receiver Propagation Delay Timing 1384fa 5 LTC1384 TEST CIRCUITS Receiver Timing Test Load Driver Timing Test Load DRIVER INPUT DRIVER OUTPUT RX OUTPUT RX INPUT DRIVER 51pF RX 3k 51pF LTC1384 • TA04 LTC1384 • TA03 ESD Test Circuit 0.1µF 2 17 4 3 5 0.1µF LOGIC INPUT 6 LTC1384 VCC 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 LTC1384 • TA04 1384fa 6 LTC1384 U PACKAGE DESCRIPTIO G Package 20-Lead Plastic SSOP (5.3mm) (Reference LTC DWG # 05-08-1640) 6.90 – 7.50* (.272 – .295 ) 1.25 ±0.12 7.8 – 8.2 20 19 18 17 16 15 14 13 12 11 5.3 – 5.7 7.40 – 8.20 (.291 – .323) 0.42 ±0.03 0.65 BSC RECOMMENDED SOLDER PAD LAYOUT 1 2 3 4 5 6 7 8 9 10 5.00 – 5.60** (.197 – .221) 2.0 (.079) 0° – 8° 0.65 (.0256) BSC 0.55 – 0.95 (.022 – .037) 0.09 – 0.25 (.0035 – .010) 0.05 (.002) 0.22 – 0.38 (.009 – .015) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) G20 SSOP 0802 3. DRAWING NOT TO SCALE *DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED .152mm (.006") PER SIDE **DIMENSIONS DO NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED .254mm (.010") PER SIDE 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) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 ( 8.255 +0.889 –0.381 ) .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) .020 (0.508) MIN .065 (1.651) TYP .120 (3.048) MIN .005 (0.127) MIN .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) .018 ± .003 (0.457 ± 0.076) N18 1002 1384fa 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 LTC1384 U PACKAGE DESCRIPTIO 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) .050 (1.270) BSC NOTE 3 NOTE: 1. DIMENSIONS IN .016 – .050 (0.406 – 1.270) .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 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1780/LT1781 5V, 2 Driver, 2 Receiver RS232 Transeivers ±15kV ESD per IEC 1000-4 LTC1382 5V, 2 Driver, 2 Receiver RS232 Transceiver 220µA Supply Current, 0.2µA in Shutdown LTC1383 5V, 2 Driver, 2 Receiver RS232 Transceiver 220µA Supply Current, Narrow 16-pin SO 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 1384fa 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 ● WWW.linear.com LINEAR TECHNOLOGY CORPORATION 1994