3

FN6045.6

May 13, 2010

Pin Descriptions

PIN

FUNCTION

VCC

System power supply input (2.7V to 5.5V).

V+

Internally generated positive transmitter supply (+5.5V).

V-

Internally generated negative transmitter supply (-5.5V).

GND

Ground connection. This is also the potential of the thermal pad (PD)

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.

TIN

TTL/CMOS compatible transmitter Inputs.

TOUT

RIN

ROUT

TTL/CMOS level receiver outputs.

INVALID

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

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 power-down circuitry thereby keeping transmitters active. (FORCEOFF must be high).

EN

Active low receiver enable control.

PD

Exposed Thermal Pad. Connect to GND.

Typical Operating Circuits

ISL3232E

14

0.1µF

+

0.1µF

+

0.1µF

9

8

12

5

15

1

16

4

V+

V-

C1+

C1-

C2+

C2-

+

0.1µF

2

3

11

5k

Ω

6

7

5k

Ω

10

+

GND

+3.3V

+ 0.1µF

13

TTL/CMOS

LOGIC LEVELS

RS-232

LEVELS

ISL3232E, ISL4221E, ISL4223E