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Issue A

ML145407

5 Volt Only Driver/Receiver

RS232 EIA–232–E and CCITT V.28

Legacy Device: Motorola MC145407

The ML145407 is a silicon–gate CMOS IC that combines three

drivers and three receivers to fulfill the electrical specifications of

RS232 EIA–232–E and CCITT V.28 while operating from a single + 5

V power supply. A voltage doubler and inverter convert the + 5V to ±

10 V. This is accomplished through an on–board 20 kHz oscillator

and four inexpensive external electrolytic capacitors. The three drivers

and three receivers of the ML145407 are virtually identical to those of

the ML145406. Therefore, for applications requiring more than three

drivers and/or three receivers, an ML145406 can be powered from an

ML145407, since the ML145407 charge pumps have been designed to

guarantee ± 5 V at the output of up to six drivers. Thus, the

ML145407 provides a high–performance, low–power, stand–alone

solution or, with the ML145406, a + 5 V only, high–performance

two–chip solution.

This device offers the following performance features:

• Operating Temperature Range = TA –40° to +85°C

Drivers

• ± 7.5 V Output Swing

• 300

Ω Power–Off Impedance

• Output Current Limiting

• TTL and CMOS Compatible Inputs

• Slew Rate Range Limited from 4 V/µs to 30 V/µs

Receivers

• + 25 V Input Range

• 3 to 7 k

Ω Input Impedance

• 0.8 V Hysteresis for Enhanced Noise Immunity

Charge Pumps

• + 5 V to ± 10 V Dual Charge Pump Architecture

• Supply Outputs Capable of Driving Three On–Chip Drivers and

Three Drivers on the ML145406 Simultaneously

• Requires Four Inexpensive Electrolytic Capacitors

• On–Chip 20 kHz Oscillator

P DIP 20 = RP

PLASTIC DIP

CASE 738

SOG 20 = -6P

SOG PACKAGE

CASE 751D

20

1

20

1

CROSS REFERENCE/ORDERING INFORMATION

MOTOROLA

P DIP 20

MC145407P

ML145407RP

SOG 20

MC145407DW

ML145407-6P

LANSDALE

PACKAGE

Note: Lansdale lead free (Pb) product, as it

becomes available, will be identified by a part

number prefix change from ML to MLE.

R

R

D

R

D

D

C2+

GND

C2–

VSS

Rx1

Tx1

Rx2

Tx2

Rx3

Tx3

C1+

VCC

C1–

VDD

DO1

DI1

DO2

DI2

DO3

DI3

20

19

18

17

16

15

14

13

12

11

1

2

3

4

5

6

7

8

9

10

PIN ASSIGNMENT

D = DRIVER

R = RECEIVER