ST ST3232B, ST3232C User Manual

3 to 5.5 V, low power, up to 400 kbps

Features

■ 300 µA supply current

■ 300 kbps minimum guaranteed data rate

■ 6 V/µs minimum guaranteed slew rate

■ Meet EIA/TIA-232 specifications down to 3 V

■ Available in SO-16, SO-16 large and TSSOP16

Description

The ST3232 is a 3 V powered EIA/TIA-232 and
V.28/V.24 communication interface with low power
requirements, high data-rate capabilities.

ST3232 has a proprietary low dropout transmitter
output stage providing true RS-232 performance
from 3 to 5.5 V supplies. The device requires only
four small 0.1 mF standard external capacitors for
operations from 3 V supply.

ST3232B
ST3232C

RS-232 drivers and receivers

SO-16

TSSOP16

Equipment, Hand-Held Equipment, Peripherals
and Printers.

SO-16 Large

The ST3232 has two receivers and two drivers.

The device is guaranteed to run at data rates of
250 kbps while maintaining RS-232 output levels.
Typical applications are Notebook, Subnotebook
and Palmtop Computers, Battery Powered

Table 1. Device summary

Order codes Temp. range Package Packaging

ST3232CDR 0 to 70 °C SO-16 (tape and reel) 2500 parts per reel

ST3232BDR -40 to 85 °C SO-16 (tape and reel) 2500 parts per reel

ST3232CWR 0 to 70 °C SO-16 Large (tape and reel) 1000 parts per reel

ST3232BWR -40 to 85 °C SO-16 Large (tape and reel) 1000 parts per reel

ST3232CTR 0 to 70 °C TSSOP16 (tape and reel) 2500 parts per reel

ST3232BTR -40 to 85 °C TSSOP16 (tape and reel) 2500 parts per reel

February 2008 Rev 11 1/18

www.st.com

18

Contents ST3232B - ST3232C

Contents

1 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2/18

ST3232B - ST3232C Pin configuration

1 Pin configuration

Figure 1. Pin connection

Table 2. Pin description

Pin n° Symbol Name and function

1C

+ Positive terminal for the first charge pump capacitor

1

2 V+ Doubled voltage terminal

3C

4C

5C

- Negative terminal for the first charge pump capacitor

1

+ Positive terminal for the second charge pump capacitor

2

- Negative terminal for the second charge pump capacitor

2

6 V- Inverted voltage terminal

7T2

8R2

9R2

10 T2

11 T1

12 R1

13 R1

14 T1

OUT

IN

OUT

IN

IN

OUT

IN

OUT

Second transmitter output voltage

Second receiver input voltage

Second receiver output voltage

Second transmitter input voltage

First transmitter input voltage

First receiver output voltage

First receiver input voltage

First transmitter output voltage

15 GND Ground

16 V

CC

Supply voltage

3/18

Absolute maximum ratings ST3232B - ST3232C

2 Absolute maximum ratings

Table 3. Absolute maximum ratings

Symbol Parameter Value Unit

V

CC

V+ Doubled voltage terminal (V

V- Inverted voltage terminal 0.3 to -7 V

V+ +|V-| 13 V

T

IN

R

IN

T

OUT

R

OUT

t

SHORT

Supply voltage -0.3 to 6 V

- 0.3) to 7 V

CC

Transmitter input voltage range -0.3 to 6 V

Receiver input voltage range ± 25 V

Transmitter output voltage range ± 13.2 V

Receiver output voltage range -0.3 to (VCC + 0.3) V

Transmitter output short to gnd time Continuous

Note: Absolute maximum ratings are those values beyond which damage to the device may occur.

Functional operation under these condition is not implied.

Externally applied V+ and V- can have a maximum magnitude of +7 V, but their absolute
addition can not exceed 13 V.

Running on internal charge pump, intrinsic self limitation allows exceeding those values
without any damage.

Startup voltage sequence (V

, then V+, then V-) is critical, therefore it is not recommended

CC

to use this device using externally applied voltage to V+ and V-.

4/18

ST3232B - ST3232C Electrical characteristics

3 Electrical characteristics

Table 4. Electrical characteristics (C

otherwise specified. Typical values are referred to T

- C4 = 0.1 µF, VCC = 3 V to 5.5 V, TA = -40 to 85 °C, unless

1

= 25 °C)

A

Symbol Parameter Test conditions Min. Typ. Max. Unit

I

SUPPLYVCC

Power supply current

No Load, V

No Load, V

= 3V ± 10%, TA = 25°C 0.3 1 mA

CC

= 5V ± 10%, TA = 25°C 1 2 mA

CC

Table 5. Logic input (C1 - C4 = 0.1 µF, VCC = 3 V to 5.5 V, TA = -40 to 85 °C, unless otherwise

specified. Typical values are referred to T

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

TIL

V

TIH

I

IL

1. Transmitter input hysteresis is typically 250mV.

Input logic threshold low T-IN

Input logic threshold high

Input leakage current T-IN ± 0.01 ± 1µA

(1)

VCC = 3.3V 2

= 5V 2.4

V

CC

= 25 °C)

A

0.8 V

V

Table 6. Transmitter (C1 - C4 = 0.1 µF tested at 3.3 V ± 10 %, VCC = 3 V to 5.5 V, TA = -40 to 85 °C,

unless otherwise specified. Typical values are referred to T

Symbol Parameter Test conditions Min. Typ. Max. Unit

= 25 °C)

A

V

R

I

TOUT

TOUT

TSC

Output voltage swing

Transmitter output
resistance

Output short circuit current VCC = 3V or 5V, V

All transmitter outputs are loaded with
3kΩ to GND

= V+ = V- = 0V, V

V

CC

= ± 2V 300 10M Ω

OUT

= ± 12 ± 60 mA

OUT

± 5 ± 5.4 V

Table 7. Receiver (C1 - C4 = 0.1 µF tested at 3.3 V ±10 %, VCC = 3 V to 5.5 V, TA = -40 to 85 °C,

unless otherwise specified. Typical values are referred to T

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

V

V

V

RIHYS

R

V

V

RIN

RIH

RIN

ROL

ROH

Receiver input voltage operating
range

T

= 25°C, VCC = 3.3V 0.6 1.1

RS-232 Input threshold low

RIL

A

= 25°C, VCC = 5V 0.8 1.5

T

A

TA = 25°C, VCC = 3.3V 1.5 2.4

RS-232 Input threshold high

= 25°C, VCC = 5V 1.8 2.4

T

A

Input hysteresis 0.3 V

Input resistance TA = 25°C 3 5 7 kΩ

TTL/CMOS Output voltage low I

TTL/CMOS Output voltage high I

= 1.6mA 0.4 V

OUT

= -1mA VCC-0.6 VCC-0.1 V

OUT

= 25 °C)

A

-25 25 V

V

V

5/18

Electrical characteristics ST3232B - ST3232C

Table 8. Timing characteristics (C

T

= -40 to 85 °C, unless otherwise specified. Typical values are referred to TA = 25 °C)

A

Symbol Parameter Test conditions Min. Typ. Max. Unit

D

Data transfer rate

R

- C4 = 0.1 µF tested at 3.3 V ± 10 %, VCC = 3 V to 5.5 V,

1

= 3kΩ, CL2= 1000pF

R

L

one transmitter switching

300 400 kbps

t

PHLR

tPLHR

|t

PHLT

- t

|t

PHLR

- t

S

Propagation delay input to
output

Transmitter propagation

|

delay difference

THL

Receiver propagation delay

|

difference

THR

Transition slew rate

RT

= R

R

XIN

, CL = 150pF 0.2 µs

XOUT

(Note 1) 100 ns

= 25°C RL = 3kΩ to 7kΩ VCC = 3.3V

T

A

measured from +3V to -3V or -3V to +3V

= 150pF to 1000pF

C

L

= 150pF to 2500pF

C

L

Note: 1 Transmitter skew is measured at the transmitter zero cross points.

50 ns

6
4

3030V/µs

V/µs

6/18