Datasheet

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LTC1337

1337fa

5V Low Power RS232

3-Driver/5-Receiver Transceiver

■

Low Supply Current: 300µA

■

ESD Protection: Over ±10kV

■

1µA Supply Current in Shutdown

■

Operates from a Single 5V Supply

■

Uses Small Capacitors: 0.1µF

■

Operates to 120k Baud

■

Three-State Outputs Are High Impedance When Off

■

Output Overvoltage Does Not Force Current Back into

Supplies

■

RS232 I/O Lines Can Be Forced to ±25V without

Damage

■

Pin Compatible with LT

1137A and LT1237

■

Flowthrough Architecture

The LTC

1337 is a 3-driver/5-receiver RS232 transceiver

with very low supply current. In the no load condition, the

supply current is only 300µA. The charge pump only

requires four 0.1µF capacitors and can supply up to 12mA

of extra current to power external circuitry.

In Shutdown mode, the supply current is further reduced

to 1µA. All RS232 outputs assume a high impedance state

in Shutdown and with the power off.

The LTC1337 is fully compliant with all data rate and

overvoltage RS232 specifications. The transceiver can

operate up to 120k baud with a 1000pF//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

3-Drivers/5-Receivers with Shutdown Supply Current

TEMPERATURE (°C)

QUIESCENT CURRENT OPERATING (µA)

600

500

400

300

200

100

20 40 60

1337 TA02

800

–20

1.2

1.0

0.8

0.6

0.4

0.2

SHUTDOWN CURRENT (µA)

QUIESCENT

CURRENT

SHUTDOWN

CURRENT

TEST CONDITION:

= 5V, ALL DRIVER INPUTS TIED TO V

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

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

1337 TA01

0.1µF

LTC1337

DRIVER 1 OUT

RX1 IN

DRIVER 2 OUT

RX2 IN

RX3 IN

RX4 IN

DRIVER 3 OUT

RX5 IN

ON/OFF

0.1µF

DRIVER 1 IN

RX1 OUT

DRIVER 2 IN

RX2 OUT

RX3 OUT

RX4 OUT

DRIVER 3 IN

RX5 OUT

–

0.1µF

GND

Summary of content (8 pages)

PAGE 1
LTC1337 5V Low Power RS232 3-Driver/5-Receiver Transceiver U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Low Supply Current: 300µA ESD Protection: Over ±10kV 1µA Supply Current in Shutdown Operates from a Single 5V Supply Uses Small Capacitors: 0.
PAGE 2
LTC1337 W W W AXI U U ABSOLUTE RATI GS U U W PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW Supply Voltage (VCC) ................................................ 6V Input Voltage Driver ....................................... – 0.3V to V CC + 0.3V Receiver ............................................... – 25V to 25V On/Off Pin .................................. – 0.3V to VCC + 0.3V Output Voltage Driver .................................................... – 25V to 25V Receiver .........................
PAGE 3
LTC1337 DC ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range. VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, unless otherwise noted. PARAMETER Power Supply Generator V + Output Voltage CONDITIONS MIN IOUT = 0mA IOUT = 12mA IOUT = 0mA IOUT = 12mA Shutdown to Turn-On V – Output Voltage Supply Rise Time Power Supply VCC Supply Current Supply Leakage Current (VCC) On/Off Threshold Low On/Off Threshold High TYP MAX UNITS 8.0 7.5 – 8.0 – 6.5 0.
PAGE 4
LTC1337 U W TYPICAL PERFOR A CE CHARACTERISTICS Driver Leakage in Shutdown Driver Short-Circuit Current 20 16 40 18 14 35 3 DRIVERS LOADED RL = 3k 12 10 8 1 DRIVER LOADED RL = 3k 6 4 2 30 25 VOUT = –20V 20 15 10 VOUT = 20V 5 0 SHORT-CIRCUIT CURRENT (mA) 45 LEAKAGE CURRENT (µA) SUPPLY CURRENT (mA) VCC Supply Current 20 10 30 20 40 50 TEMPERATURE (°C) 60 70 14 12 ISC– 10 ISC+ 8 6 4 0 0 16 2 0 10 30 20 40 50 TEMPERATURE (°C) 1337 G04 60 70 0 10 30 20 40 50 TEMPERATURE (
PAGE 5
LTC1337 U U U PI FU CTIO S DRIVER IN: RS232 Driver Input Pins. Inputs are TTL/ CMOS compatible. Inputs should not be allowed to float. Tie unused inputs to VCC. DRIVER OUT: Driver Outputs at RS232 Voltage Levels. Outputs are in a high impedance state when in Shutdown mode or VCC = 0V. The driver outputs are protected against ESD to ±10kV for human body model discharges. RX IN: Receiver Inputs. These pins can be forced to ±25V without damage.
PAGE 6
LTC1337 U TYPICAL APPLICATIO S Operation Using 5V and 12V Power Supplies + 12V V + 0.01µF 0.01µF 1 C1+ 3 26 C1– 4 25 5 24 6 23 7 22 8 21 DRIVER OUT RX IN DRIVER OUT RX IN TO LINE RX IN RX IN DRIVER OUT RX IN ON/0FF = 5V 2 V– 28 LTC1337 27 9 20 10 19 11 18 12 17 13 16 14 15 C2 + 0.1µF C2 – DRIVER IN + 5V VCC V+ VCC 0.1µF RX OUT DRIVER IN RX OUT TO LOGIC RX OUT RX OUT DRIVER IN RX OUT GND 1337 TA03 Typical Mouse Driving Application 0.
PAGE 7
LTC1337 U PACKAGE DESCRIPTIO G Package 28-Lead Plastic SSOP (5.3mm) (Reference LTC DWG # 05-08-1640) 9.90 – 10.50* (.390 – .413) 28 27 26 25 24 23 22 21 20 19 18 17 16 15 1.25 ±0.12 7.8 – 8.2 5.3 – 5.7 0.42 ±0.03 7.40 – 8.20 (.291 – .323) 0.65 BSC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 RECOMMENDED SOLDER PAD LAYOUT 5.00 – 5.60** (.197 – .221) 2.0 (.079) 0° – 8° 0.09 – 0.25 (.0035 – .010) 0.65 (.0256) BSC 0.55 – 0.95 (.022 – .037) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2.
PAGE 8
LTC1337 U PACKAGE DESCRIPTIO SW Package 28-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .030 ±.005 TYP .697 – .712 (17.70 – 18.08) NOTE 4 N 28 27 26 25 24 23 22 21 20 19 18 17 16 15 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 8 9 10 11 12 13 14 .037 – .