LT1342 5V RS232 Transceiver with 3V Logic Interface DESCRIPTIO FEATURES n ESD Protection Over 10kV The LT 1342 is an advanced low power three-driver, five- n 3V Logic Interface receiver RS232 transceiver. The LT1342 operates from a n Uses Small Capacitors: 0.1F, 0.2F 5V supply and a 3V logic supply. Receiver outputs can n 1A Supply Current in Shutdown interface directly to 3V logic circuits. Included on the chip n Low Power Driver Disable Operating Mode is a shutdown pin for reducing supply current to near zero. n Pin Compatible with LT1137A All receivers and drivers assume high impedance states n 120kBaud Operation for R = 3k, C = 2500pF during shutdown. L L n 250kBaud Operation for R = 3k, C = 1000pF L L The driver disable function provides additional control of n CMOS Comparable Low Power: 60mW operating mode. When driver disable is high the charge n Operates from a 5V Supply and 3V Logic Supply pump and drivers turn off. Receivers continue to operate n Easy PC Layout: Flowthrough Architecture during driver disable. n Rugged Bipolar Design n New ESD structures on the chip allow the LT1342 to Outputs Assume a High Impedance State When survive multiple 10kV strikes, eliminating the need for Off or Powered Down n costly TransZorbs on the RS232 line pins. Absolutely No Latchup The LT1342 is fully compliant with all EIA RS232 specifi- cations and operates in excess of 120kbaud even driving APPLICATI S heavy capacitive loads. n Notebook Computers , LTC and LT are registered trademarks of Linear Technology Corporation. TransZorb is a registered trademark of General Instruments, GSI. n Palmtop Computers P CA A L AT TY I L PP IC I Output Waveforms + 1 28 V V RECEIVER 2 27 0.1F 0.1F OUTPUT 5V V CC 2 0.1F 3 LT1342 26 V = 3V L C = 50pF L 2 0.1F 4 25 DRIVER 1 IN 5 24 DRIVER 1 OUT RX1 OUT DRIVER 6 23 R OUTPUT RX1 IN DRIVER 2 IN 7 22 R = 3k L DRIVER 2 OUT RX2 OUT C = 2500pF TO 3V LOGIC 8 21 L RX2 IN RX3 OUT TO LINE 9 20 RX3 IN RX4 OUT 10 19 RX4 IN DRIVER 3 IN 11 18 DRIVER 3 OUT RX5 OUT INPUT 12 17 RX5 IN GND 13 16 ON/OFF DRIVER DISABLE 14 15 LT1342 TA02 3V V NC L LT1342 TA01 1 UO UO ULT1342 ABSOLUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) Supply Voltage (V ) ................................................ 6V TOP VIEW CC ORDER PART Supply Voltage (V ) .................................................. 6V NUMBER L + V 1 28 V + V ........................................................................ 13.2V 5V V 2 27 C2 CC + + V ...................................................................... 13.2V C1 3 26 C2 LT1342CG C1 4 25 DRIVER 1 IN Input Voltage LT1342CNW + DRIVER 1 OUT 5 24 RX1 OUT Driver ........................................................... V to V LT1342CSW 6 RX1 IN 23 DRIVER 2 IN Receiver ................................................ 30V to 30V DRIVER 2 OUT 7 RX2 OUT 22 Output Voltage RX2 IN 8 RX3 OUT 21 Driver .................................................... 30V to 30V RX3 IN 9 20 RX4 OUT Receiver .................................... 0.3V to V + 0.3V RX4 IN 10 19 DRIVER 3 IN CC DRIVER 3 OUT 11 18 RX5 OUT Short-Circuit Duration + RX5 IN 12 17 GND V ................................................................... 30 sec DRIVER ON/OFF 13 16 DISABLE V ................................................................... 30 sec 3V V 14 15 NC L Driver Output .............................................. Indefinite G PACKAGE NW PACKAGE Receiver Output .......................................... Indefinite 28-LEAD PLASTIC SSOP 28-LEAD WIDE PDIP Operating Temperature Range .................... 0C to 70C SW PACKAGE 28-LEAD WIDE PLASTIC SO Storage Temperature Range ................ 65C to 150C T = 125C, = 96C/ W (G) JMAX JA Lead Temperature (Soldering, 10 sec)................. 300C T = 125C, = 56C/ W (NW) JMAX JA T = 125C, = 85C/ W (SW) JMAX JA Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS Power Supply Generator + V Output 8.6 V V Output 7 V Supply Current (V ) (Note 3) 12 17 mA CC Logic Supply Current (V ) (Note 4) 0.1 1 mA L Supply Current When OFF (V ) Shutdown (Note 5) l 110 A CC Driver Disable 3 mA Logic Supply Current (V ) When OFF Shutdown (Note 5) l 110 A L Driver Disable 0.1 1 mA Supply Rise Time C1 = C2 = 0.2F, 0.2 ms + Shutdown to Turn-On C = C = 0.1F ON/OFF Pin Thresholds Input Low Level (Device Shutdown) l 1.4 0.8 V Input High Level (Device Enabled) l 2.4 1.4 V ON/OFF Pin Current 0V V 5V l 15 80 A ON/OFF DRIVER DISABLE Pin Thresholds Input Low Level (Drivers Enabled) l 1.4 0.8 V Input High Level (Drivers Disabled) l 2.4 1.4 V DRIVER DISABLE Pin Current 0V V 5V l 10 500 A DRIVER DISABLE Oscillator Frequency 130 kHz 2 U W W W U WU