ST ST3237E User Manual

ST3237E

±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

RECEIVER S ACT I VE

■ GUARENTEED DATA RATE

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

■ GUARANTEED SLEW RATE RANGE

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

■ 0.1µF EXTERNAL CAPACITORS

■ FLOW-THROUGH PINOUT

■ AVAILABLE IN SO-28 AND SSOP-28

■ LOW SUPPLY CURRENT 300µA

DESCRIPTION

The ST3237E is a 3V to 5.5V powered EIA/
TIA-232 and V .28/V.24 communica tion interfaces
high data-rate capability and enhanced
electrostatic discharge (ESD) protection a t ±8KV
using IEC1000-4-2 contact discharge and ±15kV
using Human Body M odel (HBM). The other pins
are protected with standard ESD protection at

SSOP SOP

±2kV using HBM method. The ST3237C is a
transceiver (5 drivers, 3 receivers) for fast modem
applications.
The device has a proprietary low-dropout
transmitter output stage providing true RS-232
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 mode and 1Mbps in the very high speed
operation mode while maintaining RS-232 output
levels.

Table 1: Order 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

Temperature

Range

Package Comments

Rev. 5

1/15March 2005

ST3237E

Table 2: 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

2/15

Figure 1: Pin C onfigur a tion

Table 3: Absolute Maximum Ratings

ST3237E

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

R

OUT

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
Receiver Output Voltage Range -0.3 to (VCC + 0.3)

OUTB

Short Circuit Duration on T

(one at a time)

OUT

Storage Temperature Range

Continuous

-65 to 150 °C

+0.3)

CC

± 25 V

± 13.2 V

V

V

Table 4: Sh ut do wn And Enab le 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

Table 5: ESD Performance: Transmitter 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

3/15

ST3237E

Table 6: Electrical Characteristics

(C

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

1

Typical values are referred to T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

I

SUPPLYVCC

I

SHDN

Power Supply Current SHDN=V

Shutdown Supply Current SHDN=GNDV

Table 7: Logic Input Electrical Characteristics

(C

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

1

Typical values are referred to T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

Input Logic Threshold Low

V

TIL

(Note 1)

V

V

Note 1: Transmitter in put hysteres i s i s typically 250mV

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

= 25°C)

A

No Load 0.3 1 mA

=GND or V

CC

15µA

= 25°C)

A

CC

T_IN

T-IN, VHSCI, EN, SHDN 0.8 V

= 5V 2.4

V

CC

0.25 V

Table 8: Transmitter Electrical Characteristics

(C

- C4 = 0.1µF tested at 3.3V±10%, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified.

1

Typical values are referred to T

= 25°C)

A

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

R

I

Output Voltage Swing All Transmitter outputs are loaded with

TOUT

Transmitter Output Resistance VCC = 0V V

TOUT

Output Short Circuit Current ± 60 mA

I

SC

Output Leakage Current VCC = 0V or 3.3V to 5.5V V

TOL

3KΩ to GND

= ± 2V 300 10M Ω

OUT

= ± 12V

OUT

± 5 ± 5.4 V

± 25 µA

Transmitters Disable

Table 9: Receiver Electrical Characteristics

(C

- C4 = 0.1µF tested at 3.3V±10%, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified.

1

Typical values are referred to T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

I

Output Leakage Current Receiver Disabled EN = V

OL

Output Voltage Low I

V

OL

V

V

V

V

V

R

Output Voltage High I

OH

Receiver Input Voltage

RIN

Operating Range
RS-232 Input Threshold

RIL

Low
RS-232 Input Threshold

RIH

High
Input Hysteresis 0.3 V

RIHYS

Input Resistance TA = 25°C 3 5 7 KΩ

RIN

= 25°C)

A

CC

= 1mA 0.4 V

OUT

= -1mA VCC-0.6VCC-0.1 V

OUT

± 0.05 ± 10 µA

-25 25 V

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

4/15

ST3237E

Table 10: Timing Characteristics

(C

- C4 = 0.1µF tested at 3.3V±10%, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified.

1

Typical values are referred to T

Symbol Parameter Test Conditions Min. Typ. Max. Unit

D

Maximum Data Rate RL = 3KΩ CL= 1000pF

R

t

PHLR

t

t

PHLR

t

t

T_SKEW

t

R_SKEW

t

t

Propagation Delay Input to
Output

PLHR

Propagation Delay Input to
Output

PLHR

Transmitter Skew |t

Receiver Skew |t
Receiver Output Enable

OER

Time
Receiver Output Disable

ODR

Time

S

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

RT

= 25°C)

A

250 Kbps

one transmitter switching
VHSCI=GND

R

= 3KΩ CL= 250pF

L

1000 Kbps

one transmitter switching
VHSCI=V

CC

VCC= 3 to 4.5V

= 3KΩ CL= 1000pF

R

L

1000 Kbps

one transmitter switching
VHSCI=V

CC

VCC= 4.5 to 5.5V
RIN to R

OUT

CL = 150pF 0.15 µs

RL = 3kΩ CL = 1000pF
VHSCI=V

CC

VHSCI=GND

- t

PHL

|t

PHL
PHL

| VHSCI=GND 300 ns

TLH

- t

| VHSCI=V

TLH

- t

| 100 ns

TLH

CC

400

1000

50 ns

Normal Operation 50 ns

Normal Operation 120 ns

measured from +3V to -3V or -3V to +3V
CL = 150pF to 1000pF

VHSCI=GND
CL = 150pF to 1000pF VHSCI=V

CC

6

24

4

30

150

30

CL = 150pF to 2500pF
VHSCI=GND

V/µs
V/µs
V/µs

ns
ns

Transmi t ter Skew is me asured at th e tr ansmitter zero cross poi nts

5/15

ST3237E

Figure 2: Application Circ uits

Table 11: 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

6/15

C1 C2 C3 C4 Cbypass

ST3237E

TYPICAL PERFORMANCE CHARACTERISTICS (unless otherwise specified Tj = 25°C )
Figure 3: LOW Level Receiver Output Current Figure 4: HIGH Level Receiver Output Current

Figure 5: ESD Protection

Note: The High ESD protected pin s are the I/O RS232 line, transmitter out and receiver in. The other pins guarant ee ± 2KV HBM ESD pro­tection v ersus ground by means of di odes.

APPLICATION NOTE

This application note des cribes the procedure for
determining the susceptibility and the test method
to verify ST ESD advanced pro tection on RS-232
or RS485 I/O device.

Static electricity is defined as a n electrical charge
caused by an 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 defined as the transfer
of charge between bodies at different electrical
potentials. Electrostatic discharge (ESD) can
change the electrical characteristics of a

semiconductor device, degrading or destroy ing it.
Any input or output port (I/O) allows access
communication with ot her pieces of equipment by
external 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 HUMAN
BODY MODEL (HBM) event. A similar discharge
can occur from a charged conductive object, such
as a metallic tool or fixture. The model used to
characterize this event is known as the Machine
Model. A Human Body Model circuit and
waveform is presented in Figures below.

7/15

ST3237E

Figure 6: Human Body Model C i rcuit

Figure 7: Human Body Model C urrent W av eform

The second model is IEC 1000-4-2 and is used to
simulate the reaction of the device on equipment
when subjected to electros tatic discha rges , which
may occur from personnel to objects near vital

Figure 8: IEC 1000-4-2 Circuit

8/15

instrumentation. Direct (Contact) and indi rect (Air
Gap) applications o f discharges to t he equipment
under test (EUT) are possible. Test characteristics
are shown in circuit, waveform and table below.

Figure 9: IEC 1000-4-2 Current Waveform

Table 12: Characteristics Of The ESD Generator

ST3237E

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 Peak Current of

Discharge (± 10%)

Rise Time With Discharge

Switch

Current at 30 ns

(± 30%)

Current at 60 ns

(± 30%)

9/15

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

10/15

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

K0˚ 10˚ 0˚ 10˚

L 0.55 0.75 0.95 0.022 0.030 0.037

11/15

ST3237E

Tape & Reel SO-28 MECHANICAL DATA

mm. inch

DIM.

MIN. TYP MAX. MIN. TYP. MAX.

A 330 12.992
C 12.8 13.2 0.504 0.519
D 20.2 0.795
N 60 2.362

T 30.4 1.197

Ao 10.8 11.0 0.425 0.433
Bo 18.2 18.4 0.716 0.724
Ko 2.9 3.1 0.114 0.122
Po 3.9 4.1 0.153 0.161

P 11.9 12.1 0.468 0.476

12/15

ST3237E

Tape & Reel SSOP28 MECHANICAL DATA

mm. inch

DIM.

MIN. TYP MAX. MIN. TYP. MAX.

A 330 12.992
C 12.8 13.2 0.504 0.519
D 20.2 0.795
N 60 2.362

T 22.4 0.882
Ao 8.4 8.6 0.331 0.339
Bo 10.7 10.9 0.421 0.429
Ko 2.9 3.1 0.114 0.122
Po 3.9 4.1 0.153 0.161

P 11.9 12.1 0.468 0.476

13/15

ST3237E

Table 13: Revision History

Date Revision Description of Changes

21-Mar-2005 5 TSSOP has been removed.

14/15

ST3237E

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted
by implic ati o n or ot h er wis e und er an y pat ent or pa te nt r igh ts of STMi cr oe l ect ro ni cs . Sp ec if i cat i on s ment i o ned i n th is p ub li c ati on ar e s ubj ec t
to change without notice. This publication supersedes and repla ces all information previously supplied. STMicroelectronics products ar e not
authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.

The ST logo is a registered trademark of STMicroelectronics

All other names are the property of their respective owners

© 2005 STMicroelectronics - All Rights Reserved

STMicroelectronics group of companies

Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan -

Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America

www.st.com

15/15

WWW.ALLDATASHEET.COM

Copyright © Each Manufacturing Company.

All Datasheets cannot be modified without permission.

This datasheet has been download from :

www.AllDataSheet.com

100% Free DataSheet Search Site.

Free Download.

No Register.

Fast Search System.

www.AllDataSheet.com