LT1331 3V RS562 or 5V/3V RS232 Transceiver with One Receiver Active in Shutdown DESCRIPTIO FEATURES n RS232 Compatible 3V Operation The LT 1331 is a 3-driver, 5-receiver RS232 transceiver n 3V Logic Interface designed for 3V and mixed 3V/5V systems. Receivers n ESD Protection Over 10kV operate from 3V logic supply V , while the onboard charge L n 120kbaud Operation for R = 3k, C = 2500pF pump and drivers operate from 5V or 3V supply V . L L CC n 250kbaud Operation for R = 3k, C = 1000pF L L The transceiver has two shutdown modes. One mode n One Low Power Receiver Remains Active While disables the drivers and the charge pump, the other shuts in Shutdown down all circuitry except for one low power receiver which n 60A Supply Current in Shutdown can be used for ring detection. The V supply may be shut CC n Low Power Driver Disable Mode down while in ring detection mode. While shut down, the n Uses Small Capacitors: 0.1F, 0.2F drivers and receivers assume high impedance output n CMOS Comparable Low Power: 60mW states. n Easy PC Layout: Flowthrough Architecture n The LT1331 is fully compliant with all EIA-RS232 specifi- Rugged Bipolar Design n cations when V = 5V. If V = 3V, output drive levels are Outputs Assume a High Impedance State When CC CC compatible with all known interface circuits. Special bipo- Off or Powered Down lar construction techniques protect the drivers and receiv- ers beyond the fault conditions stipulated for RS232. The APPLICATI S RS232 I/O pins are resilient to multiple 10kV ESD strikes. n Notebook Computers An advanced driver output stage operates up to 120kbaud n Palmtop Computers while driving heavy capacitive loads. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATI 3.3V Operation RECEIVER + V 1 28 V OUTPUT + C = 50pF 2 27 L 0.1F 0.1F V = 3.3V CC 2 0.1F 3 LT1331 26 + 2 0.1F 4 25 DRIVER 1 IN 5 24 DRIVER R DRIVER 1 OUT RX1 OUT OUTPUT 6 23 RX1 IN DRIVER 2 IN R = 3k L 7 22 C = 2500pF DRIVER 2 OUT L RX2 OUT 8 21 TO LOGIC RX2 IN RX3 OUT TO LINE 9 20 RX3 IN RX4 OUT 10 19 RX4 IN DRIVER 3 IN INPUT 11 18 RX5 OUT (LOW-Q) DRIVER 3 OUT 12 17 RING DETECT IN RX5 IN (LOW-Q) GND 13 16 CONTROLLER ON/OFF 1331 TA02 DRIVER DISABLE OR 14 15 3.3V V NC L PROCESSOR SHUTDOWN CONTROL OUT 1331 TA01 1 + + O U UO ULT1331 ABSOLUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW Supply Voltage (V ) ................................................ 6V CC ORDER PART + Supply Voltage (V ) .................................................. 6V V 1 28 V NUMBER L + 5V/3V V 2 27 C2 V ........................................................................ 13.2V CC + + C1 3 26 C2 V ...................................................................... 13.2V LT1331CG C1 4 25 DRIVER 1 IN Input Voltage LT1331CNW DRIVER 1 OUT 5 24 RX1 OUT + Driver ........................................................... V to V LT1331CSW RX1 IN 6 23 DRIVER 2 IN Receiver ................................................ 30V to 30V DRIVER 2 OUT 7 22 RX2 OUT ON/OFF ...................................... 0.3V to V + 0.3V RX2 IN 8 21 RX3 OUT CC RX3 IN 9 20 RX4 OUT DRIVER DISABLE ...................... 0.3V to V + 0.3V CC RX4 IN 10 19 DRIVER 3 IN Output Voltage RX5 OUT DRIVER 3 OUT 11 18 (LOW-Q) Driver ................................................... 30V to 30V RX5 IN 12 17 GND (LOW-Q) Receiver ...................................... 0.3V to V + 0.3V DRIVER L ON/OFF 13 16 DISABLE Short Circuit Duration 3.3V V 14 15 NC L + V ................................................................... 30 sec G PACKAGE NW PACKAGE V ................................................................... 30 sec 28-LEAD SSOP 28-LEAD PDIP SW PACKAGE Driver Output .............................................. Indefinite 28-LEAD PLASTIC SO Receiver Output .......................................... Indefinite T = 125C, = 96C/ W (G) JMAX JA T = 125C, = 56C/ W (NW) Operating Temperature Range .................... 0C to 70C JMAX JA T = 125C, = 85C/ W (SW) JMAX JA Storage Temperature Range ................ 65C to 150C Consult factory for Industrial and Military grade parts. Lead Temperature (Soldering, 10 sec)................. 300C ELECTRICAL CHARACTERISTICS (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS Power Supply Generator + V Output V = 5V 8.6 V CC V = 3.3V 5.5 V CC V Output V = 5V 7.0 V CC V = 3.3V 4.8 V CC Supply Current (V)V = 5V (Note 3) l 12 17 mA CC CC V = 3.3V l 12 17 mA CC Supply Current (V ) (Note 4) l 35 mA L Supply Current When OFF (V ) Shutdown (Note 5) l 250 A CC Driver Disable 0.1 1 mA Supply Current When OFF (V ) Shutdown (Note 5) l 60 100 A L Driver Disable 3 5 mA + Supply Rise Time, Shutdown to Turn-On C1 = C2 = 0.2F, C = C = 0.1F 0.2 ms ON/OFF Pin Thresholds Input Low Level (Device Shut Down) 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