LTC1384

LTC1384 5V Low Power RS232 Transceiver with 2 Receivers Active in Shutdown FEATURES s s s DESCRIPTIO s s s s s s 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 LTC1384 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 kept active and ICC drops to 35µA. The receiver outputs may be forced into three-state at any time using the receiver enable (EN) pin. 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. APPLICATI s s S Notebook Computers Palmtop Computers TYPICAL APPLICATI 2 0.1µF 4 5 0.1µF 6 12 VCC 300k LOGIC INPUT LOGIC OUTPUT 11 13 LTC1384 VCC 300k 2-Drivers/2-Receivers with Shutdown and Receiver Enable 17 3 7 0.1µF 15 QUIESCENT CURRENT (µA) Quiescent and Shutdown Supply Current vs Temperature 1200 60 TEST CONDITION: VCC = 5V 0.1µF VCC = 5V 1000 800 600 400 200 0 –20 QUIESCENT CURRENT SHUTDOWN CURRENT LOGIC INPUT 232 OUTPUT 8 14 5k 232 OUTPUT 232 INPUT 0 LOGIC OUTPUT ON/OFF 10 18 5k 9 16 232 INPUT 1 RX EN LTC1384 • TA01 U 50 SHUTDOWN CURRENT (µA) UO UO 40 30 20 10 0 20 40 TEMPERATURE (°C) 60 80 LTC1384 • TA02 1 LTC1384 ABSOLUTE AXI U RATI GS Short-Circuit Duration V + ................................................................... 30 sec V – ................................................................... 30 sec Driver Output .............................................. Indefinite Receiver Output .......................................... Indefinite Operating Temperature Range .................... 0°C to 70°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C 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 PACKAGE/ORDER I FOR ATIO TOP VIEW RX EN C1 + V+ C1 – C2 + C2 – V– TR2 OUT RX2 IN 1 2 3 4 5 6 7 8 9 20 ON/OFF 19 VCC 18 GND 17 TR1 OUT 16 RX1 IN 15 RX1 OUT 14 TR1 IN 13 TR2 IN 12 RX2 OUT 11 NC G PACKAGE 20-LEAD SSOP TJMAX = 125°C, θJA = 135°C/W ORDER PART NUMBER LTC1384CG NC 10 Consult factory for Industrial and Military grade parts. DC ELECTRICAL CHARACTERISTICS VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, VON/OFF = VCC, EN = 0V, unless otherwise noted. 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 CONDITIONS 3k to GND Positive Negative q q q q q q q q q q Input Low Level (VOUT = High) Input High Level (VOUT = Low) VIN = VCC VIN = 0V VOUT = 0V Shutdown or VCC = 0V (Note 3), VOUT = ± 20V Input Low Threshold Input High Threshold – 10V ≤ VIN ≤ 10V Output Low, IOUT = – 1.6mA (VCC = 5V) Output High, IOUT = 160µA (VCC = 5V) 2 U U W WW U W TOP VIEW RX EN C1+ V+ C1– C2+ C2 – V– TR2 OUT RX2 IN 1 2 3 4 5 6 7 8 9 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 ORDER PART NUMBER LTC1384CN LTC1384CS N PACKAGE S PACKAGE 18-LEAD PLASTIC DIP 18-LEAD PLASTIC SOL TJMAX = 125°C, θJA = 56°C/W MIN 5.0 – 5.0 2.0 TYP 7.0 – 6.5 1.4 1.4 – 20 ±12 ± 10 MAX UNITS V V V V µA µA mA µA V V V kΩ V V 0.8 5 – 40 ± 500 0.8 0.1 3 3.0 q q 1.3 1.7 0.4 5 0.2 3.2 2.4 1 7 0.4 LTC1384 DC ELECTRICAL CHARACTERISTICS VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, VON/OFF = VCC, EN = 0V, unless otherwise noted. PARAMETER Output Short-Circuit Current Output Leakage Current 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 Sinking Current, VOUT = VCC Sourcing Current, VOUT = 0V EN = VCC, 0V ≤ VOUT ≤ VCC IOUT = 0mA IOUT = 8mA IOUT = 0mA IOUT = – 8mA Shutdown to Turn-On No Load (Note 2) Shutdown (Note 3) q q q q MIN – 15 10 q TYP – 40 20 1 8.0 7.5 – 8.0 – 7.0 0.2 0.22 35 1.4 1.4 MAX 10 UNITS mA mA µA V V V V ms 0.5 50 0.8 2.0 mA µA V V AC CHARACTERISTICS PARAMETER Slew Rate Driver Propagation Delay (TTL to RS232) Receiver Propagation Delay (RS232 to TTL) 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 q q q q 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 The q denotes specifications which apply over the operating temperature range of 0°C ≤ TA ≤ 70°C. 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 PERFORMANCE CHARACTERISTICS Driver Output Voltage vs Temperature 10 8 RL = 3k OUTPUT HIGH VCC = 5V DRIVER OUTPUT VOLTAGE (V) THRESHOLD 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 LTC1384 • 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 LTC1384 • TPC02 LTC1384 • TPC03 3 LTC1384 TYPICAL PERFORMANCE CHARACTERISTICS VCC Supply Current vs Temperature 18 16 18 16 50 ISC – 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 SHORT-CIRCUIT CURRENT (mA) LTC1384 • 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 LTC1384 • TPC07 4 UW Driver Short-Circuit Current vs Temperature 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 LTC1384 • TPC05 LTC1384 • TPC06 Driver Output Waveforms DRIVER OUTPUT RL = 3k CL = 2500pF DRIVER OUTPUT RL = 3k INPUT Receiver Output Waveforms RECEIVER OUTPUT CL = 51pF INPUT LTC1384 • TPC08 LTC1384 • TPC09 LTC1384 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 EN pin. The supply current of the device drops to 35µA (two receivers alive) and both driver outputs are forced into three-state. 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 EN puts the outputs into three-state. SWITCHI G TI E WAVEFOR S DRIVER INPUT DRIVER OUTPUT t LHD VCC 1.4V 1.4V 0V V+ 0V t HLD LTC1384 • 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 0.8V t HLR VCC 0V LTC1384 • F02 0V V– Figure 2. Receiver Propagation Delay Timing 5 LTC1384 TEST CIRCUITS Driver Timing Test Load DRIVER OUTPUT DRIVER 51pF 3k Receiver Timing Test Load RX OUTPUT RX INPUT RX 51pF DRIVER INPUT LTC1384 • TA04 LTC1384 • TA03 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 LTC1384 VCC 300k 15 17 3 7 0.1µF 0.1µF VCC LOGIC INPUT 232 OUTPUT LOGIC OUTPUT ON/OFF 10 18 5k 9 16 232 INPUT LTC1384 • TA04 6 LTC1384 PACKAGE DESCRIPTION 0.205 – 0.212* (5.20 – 5.38) 0.005 – 0.009 (0.13 – 0.22) 0.022 – 0.037 (0.55 – 0.95) *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006 INCH (0.15mm). 0.300 – 0.325 (7.620 – 8.255) 0.009 – 0.015 (0.229 – 0.381) ( +0.025 0.325 –0.015 8.255 +0.635 –0.381 ) 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 Dimensions in inches (millimeters) unless otherwise noted. G Package 20-Lead SSOP 0.278 – 0.289* (7.07 – 7.33) 20 19 18 17 16 15 14 13 12 11 0.045 (1.14) 0.301 – 0.311 (7.65 – 7.90) 1 2 3 4 5 6 7 8 9 10 0.045 (1.14) 0.068 – 0.078 (1.73 – 1.99) 0° – 8° 0.0256 (0.65) BSC 0.010 – 0.015 (0.25 – 0.38) 0.002 – 0.008 (0.05 – 0.21) 20SSOP 0294 N Package 18-Lead Plastic DIP 0.905 (22.860) MAX 18 17 16 15 14 13 12 11 10 0.260 ± 0.010 (6.604 ± 0.254) 1 0.130 ± 0.005 (3.302 ± 0.127) 2 3 4 5 6 7 8 9 0.045 – 0.065 (1.143 – 1.651) 0.015 (0.381) MIN 0.065 (1.651) TYP 0.125 (3.175) MIN 0.045 ± 0.015 (1.143 ± 0.381) 0.100 ± 0.010 (2.540 ± 0.254) 0.018 ± 0.003 (0.457 ± 0.076) N18 0392 7 LTC1384 PACKAGE DESCRIPTION 0.005 (0.127) RAD MIN 0.291 – 0.299 (7.391 – 7.595) (NOTE 2) 0.010 – 0.029 × 45° (0.254 – 0.737) 0.009 – 0.013 (0.229 – 0.330) NOTE 1 0.016 – 0.050 (0.406 – 1.270) NOTE: 1. 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. 2. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006 INCH (0.15mm). 8 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 q FAX: (408) 434-0507 q TELEX: 499-3977 U Dimensions in inches (millimeters) unless otherwise noted. S Package 18-Lead Plastic SOL 0.447 – 0.463 (11.354 – 11.760) (NOTE 2) 18 17 16 15 14 13 12 11 10 SEE NOTE 0.394 – 0.419 (10.007 – 10.643) 1 2 3 4 5 6 7 8 9 0.093 – 0.104 (2.362 – 2.642) 0.037 – 0.045 (0.940 – 1.143) 0° – 8° TYP 0.050 (1.270) TYP 0.004 – 0.012 (0.102 – 0.305) 0.014 – 0.019 (0.356 – 0.482) TYP SOL18 0392 LT/GP 0594 10K • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 1994