+5V, 1µA, Single RS-232 Transceiver

with AutoShutdown

4

_______________________________________________________________________________________

Typical Operating Characteristics

-10

-6

-8

-2

-4

2

0

4

8

6

10

0

1000

2000

3000

4000

5000

TRANSMITTER OUTPUT

VOLTAGE vs. LOAD CAPACITANCE

LOAD CAPACITANCE (pF)

250kbps

250kbps

120kbps

20kbps

20kbps

120kbps

0

10

20

30

40

50

0

1000

2000

3000

4000

5000

SLEW RATE vs.

LOAD CAPACITANCE

LOAD CAPACITANCE (pF)

+SLEW

-SLEW

0

10

20

30

40

50

0

1000

2000

3000

4000

5000

OPERATING SUPPLY

CURRENT vs. LOAD CAPACITANCE

LOAD CAPACITANCE (pF)

250kbps

20kbps

120kbps

FUNCTION

PIN

NAME

1

EN

Receiver Enable Control. Drive low for normal operation. Drive high to force the receiver output

(ROUT) into a high-impedance state.

2

C1+

Positive Terminal of the Voltage Doubler Charge-Pump Capacitor

3

V+

Positive Voltage Generated by the Charge Pump

7

V-

Negative Voltage Generated by the Charge Pump

6

C2-

Negative Terminal of the Inverting Charge-Pump Capacitor

5

C2+

Positive Terminal of the Inverting Charge-Pump Capacitor

4

C1-

Negative Terminal of the Voltage Doubler Charge-Pump Capacitor

12

FORCEON

Drive high to override automatic circuitry, keeping transmitter and charge pump on.

FORCEOFF must be high (Table 1).

11

TIN

TTL/CMOS Transmitter Input

10

INVALID

Output of the Invalid Signal Detector. INVALID is pulled low if no valid RS-232 level is present on

the receiver input.

9

ROUT

TTL/CMOS Receiver Output

8

RIN

RS-232 Receiver Input

Pin Description

16

FORCEOFF

Force-Off Input, active low. Drive low to shut down transmitter, receiver, and on-board charge

pump. This overrides all automatic circuitry and FORCEON (Table 1).

15

+4.5V to +5.5V Supply Voltage

14

GND

Ground

13

TOUT

RS-232 Transmitter Output