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LTC1384

1384fa

The LTC

1384 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 kept active and I

drops to 35µA. The receiver outputs may be forced into

three-state at any time using the receiver enable (RX 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.

5V Low Power RS232

Transceiver with 2 Receivers

Active in Shutdown

■

Operates from a Single 5V Supply

Low Supply Current: I

= 220µA

■

= 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

■

Notebook Computers

■

Palmtop Computers

2-Drivers/2-Receivers with Shutdown

and Receiver Enable

Quiescent and Shutdown Supply Current

vs Temperature

TEMPERATURE (°C)

–20

QUIESCENT CURRENT (µA)

200

400

600

800

1200

20 40 60

LTC1384 • TA02

1000

TEST CONDITION: V

= 5V

SHUTDOWN CURRENT (µA)

QUIESCENT

CURRENT

SHUTDOWN

CURRENT

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

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

LTC1384 • TA01

LTC1384

0.1µF

= 5V

0.1µF

232 OUTPUT

232 INPUT

LOGIC INPUT

LOGIC OUTPUT

ON/OFF

RX EN

300k

Summary of content (8 pages)

PAGE 1
LTC1384 5V Low Power RS232 Transceiver with 2 Receivers Active in Shutdown U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LTC®1384 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 = 35µA in Shutdown Mode with Both Receivers Kept Alive ESD Protection Over ±10kV Uses Small Capacitors: 0.
PAGE 2
LTC1384 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
LTC1384 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, RX EN = 0V, unless otherwise noted.
PAGE 4
LTC1384 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 14 ISC– 12 ISC+ SHORT-CIRCUIT CURRENT (mA) 18 SHORT-CIRCUIT CURRENT (mA) SUPPLY CURRENT (mA) VCC Supply Current vs Temperature 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) LTC1384 • TPC04 60 0
PAGE 5
LTC1384 U U U 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 RX EN pin. The supply current of the device drops to 35µA (two receivers alive) and both driver outputs are forced into three-state. RX EN: TTL/CMOS Compatible Receiver Enable Pin. A logic high forces the receiver outputs into three-state.
PAGE 6
LTC1384 TEST CIRCUITS Receiver Timing Test Load Driver Timing Test Load DRIVER INPUT DRIVER OUTPUT RX OUTPUT RX INPUT DRIVER 51pF RX 3k 51pF LTC1384 • TA04 LTC1384 • TA03 ESD Test Circuit 0.1µF 2 17 4 3 5 0.1µF LOGIC INPUT 6 LTC1384 VCC 0.1µF 7 0.
PAGE 7
LTC1384 U PACKAGE DESCRIPTIO G Package 20-Lead Plastic SSOP (5.3mm) (Reference LTC DWG # 05-08-1640) 6.90 – 7.50* (.272 – .295 ) 1.25 ±0.12 7.8 – 8.2 20 19 18 17 16 15 14 13 12 11 5.3 – 5.7 7.40 – 8.20 (.291 – .323) 0.42 ±0.03 0.65 BSC RECOMMENDED SOLDER PAD LAYOUT 1 2 3 4 5 6 7 8 9 10 5.00 – 5.60** (.197 – .221) 2.0 (.079) 0° – 8° 0.65 (.0256) BSC 0.55 – 0.95 (.022 – .037) 0.09 – 0.25 (.0035 – .010) 0.05 (.002) 0.22 – 0.38 (.009 – .015) NOTE: 1.
PAGE 8
LTC1384 U PACKAGE DESCRIPTIO SW Package 18-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .030 ±.005 TYP .447 – .463 (11.354 – 11.760) NOTE 4 N 18 17 16 15 14 13 12 11 10 N .325 ±.005 .420 MIN .394 – .419 (10.007 – 10.643) NOTE 3 1 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) .005 (0.127) RAD MIN 1 2 3 4 5 6 7 .093 – .104 (2.362 – 2.642) 8 9 .037 – .045 (0.