LT1341 5V RS232 Transceiver with One Receiver Active in Shutdown DESCRIPTIO FEATURES n One Receiver Remains Active While in Shutdown The LT 1341 is an advanced low power three-driver, five- n ESD Protection Over 10kV receiver RS232 transceiver. Included on the chip is a n Uses Small Capacitors: 0.1F, 0.2F shutdown pin for reducing supply current to near zero. n 60A Supply Current in Shutdown During shutdown one receiver remains active to detect n Pin Compatible with LT1137A incoming RS232 signals, for example, to wake up a n 120kBaud Operation for R = 3k, C = 2500pF system. All other receivers and the drivers assume high L L n 250kBaud Operation for R = 3k, C = 1000pF impedance states during shutdown. L L n CMOS Comparable Low Power: 60mW The driver disable function provides additional control of n Operates from a Single 5V Supply operating mode. When driver disable is high the charge n Easy PC Layout: Flowthrough Architecture pump and drivers turn off. Receivers continue to operate n Rugged Bipolar Design during driver disable. n Outputs Assume a High Impedance State When New ESD structures on the chip allow the LT1341 to Off or Powered Down survive multiple 10kV strikes, eliminating the need for n Absolutely No Latchup n costly TransZorbs on the RS232 line pins. Available in SSOP Package The LT1341 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 TYPICAL APPLICATI Output Waveforms + V 1 28 V RECEIVER OUTPUT 2 27 0.1F 0.1F V CC C = 50pF L 2 0.1F 3 LT1341 26 2 0.1F 4 25 DRIVER 1 IN 5 24 DRIVER 1 OUT RX1 OUT DRIVER 6 23 R RX1 IN DRIVER 2 IN OUTPUT 7 22 R = 3k L DRIVER 2 OUT RX2 OUT TO LOGIC 8 21 C = 2500pF L RX2 IN RX3 OUT TO LINE 9 20 RX3 IN RX4 OUT 10 19 RX4 IN DRIVER 3 IN 11 18 RX5 OUT (LOW-Q) INPUT DRIVER 3 OUT 12 17 RING DETECT IN RX5 IN (LOW-Q) GND 13 16 CONTROLLER ON/OFF DRIVER DISABLE OR 14 15 LT1341 TA02 NC NC PROCESSOR SHUTDOWN CONTROL OUT LT1341 TA01 1 UO UO ULT1341 ABSOLUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW ORDER PART Supply Voltage (V ) ................................................ 6V CC NUMBER + V 1 28 V + V ........................................................................ 13.2V 5V V 2 27 C2 CC V ...................................................................... 13.2V + + C1 3 26 C2 LT1341CG Input Voltage C1 4 25 DRIVER 1 IN LT1341CNW + Driver ........................................................... V to V DRIVER 1 OUT 5 24 RX1 OUT LT1341CSW RX1 IN 6 23 DRIVER 2 IN Receiver ................................................ 30V to 30V DRIVER 2 OUT 7 22 RX2 OUT Output Voltage RX2 IN 8 21 RX3 OUT Driver .................................................... 30V to 30V RX3 IN 9 20 RX4 OUT Receiver .................................... 0.3V to V + 0.3V CC RX4 IN 10 19 DRIVER 3 IN RX5 OUT Short Circuit Duration DRIVER 3 OUT 11 18 (LOW-Q) + RX5 IN V ................................................................... 30 sec 12 GND 17 (LOW-Q) DRIVER ON/OFF 13 16 V ................................................................... 30 sec DISABLE NC 14 15 NC Driver Output .............................................. Indefinite Receiver Output .......................................... Indefinite G PACKAGE NW PACKAGE 28-LEAD PLASTIC SSOP 28-LEAD (WIDE) PDIP Operating Temperature Range SW PACKAGE LT1341C ................................................. 0C to 70C 28-LEAD (WIDE) PLASTIC SO Storage Temperature Range ................ 65C to 150C T = 125C, = 96C/ W (G) JMAX JA T = 125C, = 56C/ W (NW) JMAX JA Lead Temperature (Soldering, 10 sec)................. 300C 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) 14 17 mA CC ) Shutdown (Note 4) l 0.06 0.150 mA Supply Current When OFF (V CC Driver Disable 3 mA Supply Rise Time C1 = C2 = 0.2F, 0.2 ms + Shutdown to Turn-On C = C = 0.1F l 1.4 0.8 V ON/OFF Pin Thresholds Input Low Level (Device Shut Down) 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