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MAX3318

2.5-V 460-kbps RS-232 TRANSCEIVER

WITH

±15-kV ESD PROTECTION

SLLS687 – OCTOBER 2005

TERMINAL FUNCTIONS

TERMINAL

DESCRIPTION

NAME

NO.

C1+

2

Positive voltage-doubler charge-pump capacitor

C1–

4

Negative voltage-doubler charge-pump capacitor

C2+

5

Positive inverting charge-pump capacitor

C2–

6

Negative inverting charge-pump capacitor

DIN

12, 13

CMOS driver inputs

DOUT

8, 17

RS-232 driver outputs

Force-off input, active low. Drive low to power down transmitters, receivers, and charge pump. This overrides

FORCEOFF

20

auto power down and FORCEON (see Function Table).

Force-on input, active high. Drive high to override auto power down, keeping transmitters and receivers on

FORCEON

14

(FORCEOFF must be high) (see Function Table).

GND

18

Ground

Valid signal detector output, active low. A logic high indicates that a valid RS-232 level is present on a receiver

INVALID

11

input.

Ready to transmit output, active high. READY is enabled high when V– goes below –3.5 V and the device is

READY

1

ready to transmit.

RIN

9, 16

RS-232 receiver inputs

ROUT

10, 15

CMOS receiver outputs

V+

3

2

× V

V–

7

–2

× V

19

2.25-V to 3-V single-supply voltage

5