460kbps, 1µA Supply Current,

RS-232-Compatible Transceivers in µMAX

4

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Typical Operating Characteristics

0

4

2

8

6

12

10

14

0

1000

1500

500

2000

2500

3000

SLEW RATE

vs. LOAD CAPACITANCE

LOAD CAPACITANCE (pF)

+SLEW

250 kbps DATA RATE

-SLEW

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

0

500

10001500200025003000

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

LOAD CAPACITANCE (pF)

460kbps/250kbps/120kbps

460kbps/250kbps/120kbps

0

4

2

8

6

12

10

14

0

1000

1500

500

2000

2500

3000

SUPPLY CURRENT

vs. LOAD CAPACITANCE

LOAD CAPACITANCE (pF)

20kbps

120kbps

250kbps

460kbps

Pin Description

PIN

MAX3311

MAX3313

NAME

FUNCTION

11

+5V External Power Supply. Decouple with a 0.1

µF capacitor to ground.

2

2

C1-

Negative Terminal of the Voltage Inverter Charge-Pump Capacitor

3

—

SHDN

Shutdown Active-Low (0 = off, 1 = on)

—

3

INVALID

Valid Signal Detector Output, Active-Low. A logic high indicates that a valid

RS-232 level is present on the receiver input.

4

4

TIN

TTL/CMOS Transmitter Input

5

5

ROUT

TTL/CMOS Receiver Output

6

6

RIN

RS-232 Receiver Input

7

7

TOUT

RS-232-Compatible Transmitter Output

8

8

V-

-4.3V generated by the charge pump. Connect a 0.1

µF capacitor to ground.

9

9

C1+

Positive Terminal of the Voltage Inverter Charge-Pump Capacitor

10

10

GND

Ground