Datasheet ST3237ECTR, ST3237ECPR, ST3237ECD, ST3237EBTR, ST3237EBPR Datasheet (SGS Thomson Microelectronics)

±15KV ESD-PROTECTED, 1µA, 3 TO 5.5V, 250KBPS,

RS-232 TRANSCEIVER WITH STAND-BY

■ EDS PROTECTION FOR RS-232 I/O PINS:

±15KV HUMAN BODY MODEL
±8KV IEC 1000-4-2 CONTACT DISCHARGE

■ 1µA LOW POWER SHUTDOWN WITH

RECEIVERS ACTIVE

■ GUARENTEED DATA RATE

250Kbps (Normal Operation)
1Mbps (Very High Speed Operation)

■ GUARANTEED SLEW RATE RANGE

6V/µs (Normal Operation)
24V/µs (Very High Speed Operat ion)

■ 0.1µF EXTERNAL CAPACITORS

■ FLOW-THROUGH PINOUT

■ AVAILABLE IN SO-28, SSOP-28 AND

TSSOP28

■ LOW SUPPLY CURRENT 300µA

DESCRIPTION

The ST3237E is a 3V to 5.5V powered EIA/
TIA-232 and V.28/V.24 communication interfaces
high data-rate capability and enhanced
electrostatic discharge (ESD) protection at ±8KV
using IEC1000-4-2 contact discharge and ±15kV
using H uman Body Model (HBM). The other p ins
are protected with standard ESD protection at
±2kV using HBM method. The ST3237C is a
transceiver (5 drive rs, 3 receivers) for fast modem
applications.
The device has a proprietary low-dropout
transmitter output stage prov iding true RS-232

ST3237E

SOP

SSOP

performance from a 3V to 5.5V supply using a
dual charge pump. The device is guaranteed to
run at data rates of 250Kbps in the normal
operation m ode and 1Mbps in the very high speed
operation mode while maintaining RS-232 output
levels.

TSSOP

ORDERING CODES

Type

ST3237ECD 0 to 70 °C SO-28 (Tube) 27parts per tube / 12tube per box

ST3237EBD -40 to 85 °C SO-28 (Tube) 27parts per tube / 12tube per box
ST3237ECDR 0 to 70 °C SO-28 (Tape & Reel) 1000 parts per reel
ST3237EBDR -40 to 85 °C SO-28 (Tape & Reel) 1000 parts per reel
ST3237ECPR 0 to 70 °C SSOP-28 (Tape & Reel) 1350 parts per reel
ST3237EBPR -40 to 85 °C SSOP-28 (Tape & Reel) 1350 parts per reel

ST3237ECTR (*) 0 to 70 °C TSSOP28 (Tape & Reel) 2500 parts per reel

ST3237EBTR -40 to 85 °C TSSOP28 (Tape & Reel) 2500 parts per reel

Temperature

Range

Package Comments

1/13January 2003

ST3237E

PIN DESCRIPTION

PlN N° SYMBOL NAME AND FUNCTION

1
2 GND Ground
3
4 V- -5.5V Generated by the Charge Pump
5
6
7
8

9
10
11
12
13 EN

14 SHDN
15 VHSCI Very High Speed Control Input. Connected to GND for normal

16
17
18
19
20
21
22
23
24
25
26
27 V+ 5.5V Generated by the Charge Pump
28

C

+ Positive Terminal of Inverting Charge Pump Capacitor

2

- Negative Terminal of Inverting Charge Pump Capacitor

C

2

T1
T2
T3

T4

T5

R1
R2

R3

OUT
OUT
OUT

IN
IN

OUT

IN

OUT

First Transmitter Output Voltage
Second Transmitter Output Voltage
Third Transmitter Output Voltage
First Receiver Input Voltage
Second Receiver Input Voltage
Fourth Transmitter Output Voltage
Third Receiver Input Voltage
Fifth Transmitter Output Voltage
Receiver Enable, Active Low

Shutdown Control, Active Low

operation; connected to VCC for 1Mbps transmission rates.

R1

OUTB

T5

IN

R3

OUT

T4

IN

R2

OUT

R1

OUT

T3

IN

T2

IN

T1

N

- Negative Terminal of Voltage-Doubler Charge Pump Capacitor

C

1

V

CC

+ Positive Terminal of Voltage-Doubler Charge Pump Capacitor

C

1

Non Inverting Complementary Receiver Output. Always Active.
Fifth Transmitter Input Voltage
Third Receiver Output Voltage
Fourth Transmitter Input Voltage
Second Receiver Output Voltage
First Receiver Output Voltage
Third Transmitter Input Voltage
Second Transmitter Input Voltage
First Transmitter Input Voltage

Supply Voltage

2/13

PIN CONFIGURATION

ST3237E

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

CC

Supply Voltage

-0.3 to 6 V

V+ Doubled Voltage Terminal -0.3 to 7 V

V- Inverted Voltage Terminal 0.3 to -7 V

V+ +|V-| 13 V

T

IN

SHDN

VHSCI

R

IN

T

OUT

R

OUT,ROUTB

t

SHORT

T

stg

Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied. V+ and V- can have a maximum magnitude of +7V, but their absolute addition can not exceed 13 V.

Transmitter Input Voltage Range

-0.3 to 6 V

,EN -0.3 to 6 V

Very High Speed Control Input -0.3 to (V
Receiver Input Voltage Range
Transmitter Output Voltage Range

+0.3)

CC

± 25 V

± 13.2 V

Receiver Output Voltage Range -0.3 to (VCC+ 0.3)
Short Circuit Duration on T
Storage Temperature Range

(one at a time)

OUT

Continuous

-65 to 150 °C

V

V

SHUTDOWN AND ENABLE CONTROL TRUTH TABLE

SHDN

0 0 High Z Active Active
0 1 High Z High Z Active
1 0 Active Active Active
1 1 Active High Z Active

EN T-OUT R-OUT R-OUTB

3/13

ST3237E

ESD PERFORMANCE: T RANSMITTER OUTPUTS, RECEIVER INPUTS

Symbol Parameter Test Conditions Min. Typ. Max. Unit

ESD ESD Protection Voltage Human Body Model ±15 kV
ESD ESD Protection Voltage IEC-1000-4-2 Contact Discharge ±8kV

ELECTRICAL CHARACTERISTICS

(C
Typical values are referred to T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

I

SUPPLYVCC

I

LOGIC INPUT ELECTRICAL CHARACTERISTICS

(C
Typical values are referred to T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

Note 1: Transmitter input hysteresis is typically 250mV

=0.1µF, VCC=3Vto5.5V,TA= -40 to 85°C, unles s otherwise specified.

1-C4

=25°C)

A

Power Supply Current SHDN=V

SHDN

1-C4

V

V

Shutdown Supply Current SHDN=GND V

=0.1µF, VCC=3Vto5.5V,TA= -40 to 85°C, unles s otherwise specified.

=25°C)

A

Input Logic Threshold Low

V

TIL

(Note 1)
Input Logic Threshold High T-IN, VHSCI, EN,SHDN VCC= 3.3V 2 V

TIH

Input Leakage Current T-IN, VHSCI, EN,SHDN ± 1.0 µA

I

IL

Transmitter Input

HYS

Hysteresis

T-IN, VHSCI, EN,SHDN 0.8 V

CC

No Load 0.3 1 mA

=GND or V

T_IN

CC

=5V 2.4

V

CC

15µA

0.25 V

TRANSMITTER EL ECTRICAL CHARACTERISTICS

(C
Typical values are referred to T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

R

=0.1µF tested at 3.3V±10%, VCC=3Vto5.5V,TA= -4 0 to 85°C, unless otherwise specified.

1-C4

TOUT

TOUT

I

SC

I

TOL

Output Voltage Swing All Transmitter outputs are loaded with

Transmitter Output
Resistance

Output Short Circuit Current ± 60 mA
Output Leakage Current VCC= 0V or 3.3V to 5.5V V

=25°C)

A

3KΩ to GND
VCC=0V V

± 5 ± 5.4 V

= ± 2V 300 10M Ω

OUT

= ± 12V

OUT

Transmitters Disable

± 25 µA

4/13

ST3237E

RECEIVER ELECTRICAL CHARACTERISTICS

(C
Typical values are referred to T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

=0.1µF tested at 3.3V±10%, VCC=3Vto5.5V,TA= -4 0 to 85°C, unless otherwise specified.

1-C4

=25°C)

A

Output Leakage Current Receiver Disabled EN=V

I

OL

Output Voltage Low I

V

OL

V

Output Voltage High I

OH

= 1mA 0.4 V

OUT

= -1mA VCC-0.6VCC-0.1 V

OUT

CC

± 0.05 ± 10 µA

V

V

V

V

RIHYS

R

Receiver Input Voltage

RIN

Operating Range
RS-232 Input Threshold

RIL

Low
RS-232 Input Threshold

RIH

High

TA= 25°C VCC= 3.3V 0.6 1.1 V

= 25°C VCC= 5V 0.8 1.5

T

A

TA= 25°C VCC= 3.3V 1.5 2.4 V

= 25°C VCC= 5V 1.2 2.4

T

A

Input Hysteresis 0.3 V
Input Resistance TA= 25°C 3 5 7 KΩ

RIN

-25 25 V

TIMING CHARACTERISTICS

(C
Typical values are referred to T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

t

t

t

T_SKEW

t

R_SKEW

TransmitterSkew ismeasured at the transmitter zero cross points

=0.1µF tested at 3.3V±10%, VCC=3Vto5.5V,TA= -4 0 to 85°C, unless otherwise specified.

1-C4

=25°C)

A

Maximum Data Rate RL=3KΩ CL= 1000pF

D

R

250 Kbps

one transmitter switching VHSCI=GND

=3KΩ CL= 250pF

R

L

one transmitter switching VHSCI=V

CC

1000 Kbps

VCC= 3 to 4.5V

=3KΩ CL= 1000pF

R

L

one transmitter switching VHSCI=V

CC

1000 Kbps

VCC= 4.5 to 5.5V

PHLR

t

PLHR

PHLR

t

PLHR

t

OER

t

ODR

S

RT

Propagation Delay Input to
Output

Propagation Delay Input to
Output

Transmitter Skew |t

Receiver Skew |t
Receiver Output Enable

Time
Receiver Output Disable

Time
Transition Slew Rate TA= 25°C RL= 3 to 7KΩ VCC= 3.3V

RINto R

OUT

CL= 150pF 0.15 µs

RL=3kΩ CL= 1000pF
VHSCI=V

CC

VHSCI=GND

PHL-tTLH

|t

PHL-tTLH
PHL-tTLH

| VHSCI=GND 300 ns
| VHSCI=V
| 100 ns

CC

400

1000

50 ns

Normal Operation 50 ns

Normal Operation 120 ns

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

= 150pF to 1000pF VHSCI=GND

C

L

C

= 150pF to 1000pF VHSCI=V

L

CC

CL= 150pF to 2500pF VHSCI=GND

6

24

4

30

150

30

V/µs
V/µs
V/µs

ns
ns

5/13

ST3237E

APPLICATION CIRCUITS

CAPACITANCE VALUE (µF)

V

CC

3.0 to 3.6 0.22 0.22 0.22 0.22 0.1

3.1 to 3.6 0.1 0.1 0.1 0.1 0.1

4.5 to 5.5 0.047 0.33 0.33 0.33 0.1

3.0 to 5.5 0.22 0.1 0.1 0.1 0.1

6/13

C1 C2 C3 C4 Cbypass

ST3237E

TYPICAL PERFORMANCE CHARACTERISTICS (unless otherwise specified Tj=25°C)
Figure1 : LOW Level Receiver Output Current Figure2 : HIGH Level Receiver Output Current

ESD PROTECTION

Note: The High ESD protected pins are the I/O RS232 line, transmitter out and receiver in. The other pins guarantee ± 2KV HBM ESD pro­tection versus ground by means of diodes.

7/13

ST3237E

APPLICATION NO TE

This application note describes the procedure for determining the susceptibility and the test method to
verify S T E SD advanced protection on RS-232 or RS 485 I/O device.
Static electricity is defined as an electrical charge caused by a n imbalance of electrons on the surface of
a material. This imbalance of electrons produces an electric field that can be measured and that can
influence other objects at a distance. Electrostatic discharge is def ined as the transfer of charge between
bodies at different electrical potentials. Electrostatic discharge (ESD) can change the electrical
characteristics of a s emiconductor device, degradin g or destroying it. Any input or output port (I/O) allows
access communication with other piece s of equipment by ex terna l connectors. These connectors are
directly linked by the I/O pins of RS-232 or RS485 interface. ST provides the E-series by advanced high
ESD protection structure. The protection functionality is tested in two different conditions:
The first model is used to simulate the HUM A N BODY MODEL (HBM) event. A similar d ischarge can
occur from a charged conduc tive object, such as a metallic tool or fixture. The model used to charact erize
this event is known as the Machine Model. A Human Body Model circuit and waveform is presented in
Figures below.

HUMAN BODY MODEL CIRCUIT

HUMANBO DYMODELCURRENTWAVEFO RM

The second model is IEC 1000-4-2 and is used to simulate the reaction of the device on equipment when
subjected to electrostatic discharges, which may occur from personnel to objects near vital
instrumentation. Direct (Contact) and indirect (Air Gap) applications of discharges to the equipmen t under
test (EUT) are pos sible. Test characteristics are shown in circuit, waveform and table below.

8/13

IEC 1000-4-2 CIRCUIT

IEC 1000-4-2 CURRENT WAVEFORM

ST3237E

CHARACTERISTICS OF THE ESD GENERATOR

Level

1 2 KV 7.5 A 0.7 to 1ns 4 A 2 A
2 4 KV 15 A 0.7 to 1ns 8 A 4 A
3 6 KV 22.5 A 0.7 to 1ns 12 A 6 A
4 8 KV 30 A 0.7 to 1ns 16 A 8 A

Indicated

Voltage

First PeakCurrent of

Discharge (± 10%)

Rise Time With Discharge

Switch

Current at 30 ns

(± 30%)

Current at 60 ns

(± 30%)

9/13

ST3237E

SO-28 MECHANICAL DATA

DIM.

MIN. TYP MAX. MIN. TYP. MAX.

A 2.65 0.104

a1 0.1 0.3 0.004 0.012

b 0.35 0.49 0.014 0.019

b1 0.23 0.32 0.009 0.012

C 0.5 0.020

c1 45˚ (typ.)

D 17.70 18.10 0.697 0.713
E 10. 00 10.65 0.393 0.419

e 1.27 0.050

e3 16.51 0.650

F 7.40 7.60 0. 291 0.300

L 0.50 1.27 0.020 0.050

S ˚ (max.)

mm. inch

8

10/13

0016023

ST3237E

SSOP28 MECHANICAL DATA

mm. inch

DIM.

MIN. TYP MAX. MIN. TYP. MAX.

A 2 0.079

A1 0.050 0.002

A2 1.65 1.75 1.85 0.065 0.069 0.073

b 0.22 0.38 0.009 0.015

c 0.09 0.25 0.004 0.010

D 9.9 10.2 10.5 0.390 0.402 0.413

E 7.4 7.8 8.2 0.291 0.307 0.323

E1 5 5.3 5.6 0.197 0.209 0.220

e 0.65 BSC 0.0256 BSC

K 0˚ 10˚ 0˚ 10˚

L 0.55 0.75 0.95 0.022 0.030 0.037

11/13

ST3237E

TSSOP28 MECHANICAL DATA

mm. inch

DIM.

MIN. TYP MAX. MIN. TYP. MAX.

A 1.2 0.047

A1 0.05 0.15 0.002 0.004 0.006

A2 0.8 1 1.05 0.031 0.039 0.041

b 0.19 0.30 0.007 0.012

c 0.09 0.20 0.004 0.0079

D 9.6 9.7 9.8 0.378 0.382 0.386

E 6.2 6.4 6.6 0.244 0.252 0.260

E1 4.3 4.4 4.48 0.169 0.173 0.176

e 0.65 BSC 0.0256 BSC

K0˚ 8˚0˚ 8˚

L 0.45 0.60 0.75 0.018 0.024 0.030

12/13

0128292B

ST3237E

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the
consequences of use o f suc h inf ormat ion n or f or an y infr ingeme nt of paten ts or oth er ri gh ts of third part ies whic h may resul t f rom
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information
previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or
systems without express written approval of STMicroelectronics.

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13/13