Datasheet

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LTC1382

1382fa

5V Low Power

RS232 Transceiver

with Shutdown

■

Operates from a Single 5V Supply

■

Low Supply Current: I

= 220µA

■

= 0.2µA in Shutdown Mode

■

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 LTC

1382 is an ultra-low power 2-driver/2-receiver

RS232 transceiver that operates from a single 5V

supply. The charge pump requires only four space-

saving 0.1µF capacitors.

The transceiver operates in one of two modes, Normal

and Shutdown. In the Normal mode, I

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 off and

drops to 0.2µA.

The LTC1382 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

TEMPERATURE (°C)

–20

QUIESCENT CURRENT (µA)

100

200

300

400

600

20 40 60

LTC1382 • TA02

500

TEST CONDITION: V

= 5V

SHUTDOWN CURRENT (µA)

0.2

0.4

0.6

0.8

1.2

1.0

QUIESCENT

CURRENT

SHUTDOWN

CURRENT

Quiescent and Shutdown Supply Current

vs Temperature

2-Drivers/2-Receivers with Shutdown

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

LTC1382 • TA01

LTC1382

0.1µF

= 5V

0.1µF

232 OUTPUT

300k

232 INPUT

LOGIC INPUT

LOGIC OUTPUT

300k

ON/OFF

, LTC and LT are registered trademarks of Linear Technology Corporation.

Summary of content (8 pages)

PAGE 1
LTC1382 5V Low Power RS232 Transceiver with Shutdown U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LTC®1382 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 = 0.2µA in Shutdown Mode ESD Protection Over ±10kV Uses Small Capacitors: 0.
PAGE 2
LTC1382 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.
PAGE 3
LTC1382 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, unless otherwise noted. PARAMETER Power Supply Generator V + Output Voltage CONDITIONS MIN 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 8.0 7.5 – 8.0 – 7.0 0.
PAGE 4
LTC1382 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 SHORT-CIRCUIT CURRENT (mA) 18 SHORT-CIRCUIT CURRENT (mA) SUPPLY CURRENT (mA) VCC Supply Current vs Temperature – 14 ISC 12 ISC+ 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) LTC1382 • TPC04 60 0
PAGE 5
LTC1382 U U U PI FU CTIO S VCC: 5V Input Supply Pin. This pin should be decoupled with a 0.1µF ceramic capacitor. charge pump efficiency, the capacitor’s effective series resistance should be less than 2Ω. GND: Ground Pin. 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.
PAGE 6
LTC1382 TEST CIRCUITS Receiver Timing Test Load Driver Timing Test Load DRIVER INPUT DRIVER OUTPUT RX OUTPUT RX INPUT DRIVER 51pF RX 3k 51pF LTC1382 • TA04 LTC1382 • TA03 ESD Test Circuit 0.1µF 2 17 4 3 5 0.1µF LOGIC INPUT 6 LTC1382 VCC = 5V 0.1µF 7 0.
PAGE 7
LTC1382 U PACKAGE DESCRIPTIO 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) .130 ± .005 (3.302 ± 0.127) .020 (0.508) MIN .009 – .015 (0.229 – 0.381) .065 (1.651) TYP +.035 .325 –.015 ( 8.255 +0.889 –0.381 .045 – .065 (1.143 – 1.651) .125 (3.175) MIN ) .005 (0.127) MIN .018 ± .003 (0.457 ± 0.076) .100 (2.54) BSC NOTE: 1.
PAGE 8
LTC1382 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1780/LT1781 5V, 2 Driver, 2 Receiver RS232 Transeivers ±15kV ESD per IEC 1000-4 LTC1383 5V, 2 Driver, 2 Receiver RS232 Transceiver 220µA Supply Current, Narrow 16-pin SO LTC1384 5V, 2 Driver, 2 Receiver RS232 Transceiver 220µA Supply Current, 2 Receivers Active in Shutdown LTC1385 3.3V, 2 Driver, 2 Receiver RS562 Transceiver 220µA Supply Current, 2 Receivers Active in Shutdown LTC1386 3.