Date: 7/19/04

SP202E Series High Performance RS232 Transceivers

© Copyright 2004 Sipex Corporation

4

Figure 1. Typical Circuit using the SP202E or SP232E.

FEATURES…

The SP202E/232E/233E/310E/312E devices

are a family of line driver and receiver pairs that

meet the specifications of RS-232 and V.28

serial protocols with enhanced ESD perfor-

mance. The ESD tolerance has been improved

on these devices to over

±15KV for both Human

Body Model and IEC1000-4-2 Air Discharge

Method. These devices are pin-to-pin compat-

ible with Sipex's 232A/233A/310A/312A

devices as well as popular industry standards.

As with the initial versions, the SP202E/232E/

233E/310E/312E devices feature10V/

µs slew

rate, 120Kbps data rate under load,

0.1

µF

charge pump capacitors, overall ruggedness

for commercial applications, and increased drive

current for longer and more flexible cable

configurations. This family also features Sipex's

BiCMOS design allowing low power operation

without sacrificing performance.

The SP202E/232E/233E/310E/312E devices

have internal charge pump voltage converters

which allow them to operate from a single +5V

supply. The charge pumps will operate with

polarized or non-polarized capacitors ranging

from 0.1 to 10

µF and will generate the ±6V

needed to generate the RS-232 output levels.

Both meet all EIA RS-232 and ITU V.28

specifications.

The SP310E provides identical features as the

SP232E with a single control line which

simultaneously shuts down the internal DC/DC

converter and puts all transmitter and receiver

outputs into a high impedance state. The SP312E

is identical to the SP310E with separate tri-state

and shutdown control lines.

THEORY OF OPERATION

The SP232E, SP233E, SP310E and SP312E

devices are made up of three basic circuit blocks –

1) a driver/transmitter, 2) a receiver and 3) a charge

pump. Each block is described below.

Driver/Transmitter

The drivers are inverting transmitters, which ac-

cept TTL or CMOS inputs and output the RS-232

signals with an inverted sense relative to the input

logic levels. Typically the RS-232output voltage

swing is

±6V. Even under worst case loading

conditions of 3kOhms and 2500pF, the output is

guaranteed to be

±5V, which is consistent with the

RS-232 standard specifications. The transmitter

outputs are protected against infinite short-circuits

to ground without degradation in reliability.

98

R IN

R OUT

2

12

13

R IN

R OUT

1

10

7

T IN

2

T OUT

2

11

14

T IN

1

T OUT

1

15

GND

400k Ω

400k Ω

3

1

C +

C -

1

1

6

16

V

CC

V+

+

+

0.1 F

6.3V

µ

Charge Pump

+5V INPUT

2

V-

2

1

5k Ω

0.1 F

16V

µ

5k Ω

5

4

C +

C -

2

2

+

0.1 F

16V

µ

0.1 F 6.3V

µ

10 F 6.3V

µ

SP232E

+

+

*

*The negative terminal of the V+ storage capacitor can be tied

is recommended.

SP202E