5

FN4805.21

March 1, 2006

ICL3243 (SOIC, SSOP, TSSOP)

TOP VIEW

Pinout

C2+

C2-

V-

C1+

GND

C1-

FORCEON

INVALID

V+

FORCEOFF

28

27

26

25

24

23

22

21

20

19

18

17

16

15

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Pin Descriptions

PIN

FUNCTION

System power supply input (3.0V to 5.5V).

V+

Internally generated positive transmitter supply (+5.5V).

V-

Internally generated negative transmitter supply (-5.5V).

GND

Ground connection.

C1+

External capacitor (voltage doubler) is connected to this lead.

C1-

External capacitor (voltage doubler) is connected to this lead.

C2+

External capacitor (voltage inverter) is connected to this lead.

C2-

External capacitor (voltage inverter) is connected to this lead.

TTL/CMOS compatible transmitter Inputs.

RS-232 level (nominally

±5.5V) transmitter outputs.

RS-232 compatible receiver inputs.

TTL/CMOS level receiver outputs.

TTL/CMOS level, noninverting, always enabled receiver outputs.

INVALID

Active low output that indicates if no valid RS-232 levels are present on any receiver input.

EN

SHDN

Active low input to shut down transmitters and on-board power supply, to place device in low power mode.

FORCEOFF Active low to shut down transmitters and on-chip power supply. This overrides any automatic circuitry and FORCEON (See Table 2).

FORCEON Active high input to override automatic powerdown circuitry thereby keeping transmitters active. (FORCEOFF must be high).

ICL3221, ICL3222, ICL3223, ICL3232, ICL3241, ICL3243