ST ST3237EB User Manual

ST3237EB

± 15 kV ESD protected, 1 µA, 3 to 5.5 V, 250 kbps RS-232 transceiver with stand-by

Features

■ESD protection for RS-232 I/O pins

–±15 kV human body model

–±8 kV IEC 1000-4-2 contacts discharge

■1 µA low power shutdown with receivers active

■Guaranteed data rate

–250 kbps (normal operation)

–1 Mbps (very high speed operation)

■Guaranteed slew rate range

–6 V/µs (normal operation)

–24 V/µs (very high speed operation)

■0.1 µF external capacitors

■Flow-through pinout

■Low supply current 300 µA

■Available in SSOP28 and SO-28

Description

The ST3237E is a 3 V to 5.5 V powered EIA/TIA232 and V.28/V.24 communication interfaces high data-rate capability and enhanced electrostatic discharge (ESD) protection at ±8 kV using IEC1000-4-2 contact discharge and ±15 kV using Human Body Model (HBM). The other pins are protected with standard ESD protection at ±2 kV 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 3 V to 5.5 V supply using a dual charge pump. The device is guaranteed to run at data rates of 250 kbps in the normal

SSOP

SOP

operation mode and 1 Mbps in the very high speed operation mode while maintaining RS-232 output levels.

	Table 1.	Device summary
	Order code		Temperature	Package	Packaging
			range
	ST3237EBDR		-40 to 85 °C	SO-28 (tape and reel)	1000 parts per reel
	ST3237EBPR		-40 to 85°C	SSOP28 (tape and reel)	1350 parts per reel
	November 2007			Rev 7	1/18
					www.st.com

Contents	ST3237EB

Contents

1	Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 3
2	Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
3	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
4	Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
5	Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . .	9
6	Application note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	10
7	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	12
8	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	17

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ST3237EB	Pin configuration

1 Pin configuration

Figure 1. Pin connection

Table 2.	Pin description
Pin n°		Symbol	Name and function
	1	C2+	Positive Terminal of Inverting Charge Pump Capacitor
	2	GND	Ground
	3	C2-	Negative terminal of inverting charge pump capacitor
	4	V-	5.5V generated by the charge pump
	5	T1OUT	First transmitter output voltage
	6	T2OUT	Second transmitter output voltage
	7	T3OUT	Third transmitter output voltage
	8	R1IN	First receiver input voltage
	9	R2IN	Second receiver input voltage
	10	T4OUT	Fourth transmitter output voltage
	11	R3IN	Third receiver input voltage
	12	T5OUT	Fifth transmitter output voltage
	13	EN	Receiver enable, active low
	14	SHDN	Shutdown control, active low
	15	VHSCI	Very high speed control input. Connect to GND for normal
			operation; connect to VCC for 1 Mbps transmission rates.
	16	R1OUTB	Non inverting complementary receiver output. Always active.
	17	T5IN	Fifth transmitter input voltage
	18	R3OUT	Third receiver output voltage

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Pin configuration			ST3237EB
Table 2.	Pin description (continued)
Pin n°		Symbol	Name and function
	19	T4IN	Fourth transmitter input voltage
	20	R2OUT	Second receiver output voltage
	21	R1OUT	First receiver output voltage
	22	T3IN	Third transmitter input voltage
	23	T2IN	Second transmitter input voltage
	24	T1N	First transmitter input voltage
	25	C1-	Negative terminal of voltagecharge pump capacitor
	26	VCC	Supply voltage
	27	V+	-5.5V generated by the charge pump
	28	C1+	Positive terminal of voltagecharge pump capacitor

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ST3237EB

Absolute maximum ratings

2

Absolute maximum ratings

Table 3.

Absolute maximum ratings

Symbol

Parameter

Value

Unit

VCC

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

TIN

Transmitter input voltage range

-0.3 to 6

V

-0.3 to 6

V

SHDN,

EN

VHSCI

Very high speed control input

-0.3 to (VCC +0.3)

V

RIN

Receiver input voltage range

± 25

V

TOUT

Transmitter output voltage range

± 13.2

V

ROUT,

Receiver output voltage range

-0.3 to (VCC + 0.3)

V

ROUTB

tSHORT

Short circuit duration on TOUT (one at a time)

Continuous

Tstg

Storage temperature range

-65 to 150

°C

Note:

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 +7 V, but their absolute addition can not exceed 13 V.

Table 4.

Shutdown and enable control truth table

SHDN

EN

T-OUT

R-OUT

R-OUTB

0

0

High Z

Active

Active

0

1

High Z

High Z

Active

1

0

Active

Active

Active

1

1

Active

High Z

Active

Figure 2.	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	±8			kV

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Electrical characteristics	ST3237EB

3 Electrical characteristics

Table 5. Electrical characteristics (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 TA = 25 °C)

Symbol	Parameter			Test conditions	Min.	Typ.	Max.	Unit
ISUPPLY	VCC power supply current					0.3	1	mA
			SHDN=VCC, No Load
ISHDN	Shutdown supply current					1	5	µA
			SHDN=GND, VT_IN=GND or VCC

Table 6.

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 TA = 25 °C)

Symbol

Parameter

Test conditions

Min.

Typ.

Max.

Unit

Input logic threshold low

VTIL

T-IN, VHSCI, EN, SHDN

0.8

V

(1)

VCC = 3.3V

2

VTIH

Input logic threshold high

T-IN, VHSCI, EN, SHDN

V

VCC = 5V

2.4

IIL

Input leakage current

T-IN, VHSCI,

± 1.0

µA

EN,

SHDN

VHYS

Transmitter input

0.25

V

hysteresis

1. Transmitter input hysteresis is typically 250 mV

Table 7.

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 TA = 25 °C)

Symbol

Parameter

Test conditions

Min.

Typ.

Max.

Unit

VTOUT

Output voltage swing

All transmitter outputs are loaded with

± 5

± 5.4

V

3KΩ to GND

RTOUT

Transmitter output

VCC = 0V, VOUT = ± 2V

300

10M

Ω

resistance

ISC

Output short circuit current

± 60

mA

ITOL

Output leakage current

VCC = 0V or 3.3V to 5.5V

± 25

µA

VOUT = ± 12V

Transmitters disable

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