ST ST3222EB, ST3222EC User Manual

ST3222EB

ST3222EC

± 15 kV ESD protected, 3 to 5.5 V low power, up to 250 Kbps, RS-232 drivers and receivers

Features

■ESD protection for RS-232 I/O pins ± 15 kV human body model, ± 8 kV IEC 1000-4-2 contact discharge

■300 µA supply current

■250KBps minimum guarantee data rate

■6 V/µs minimum guarantee slew rate

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

■Available in SSOP20 and TSSOP20

Description

The ST3222E is a 3 V powered EIA/TIA-232 and V.28/V.24 communications interface with low power requirements, high data-rate capabilities and enhanced electrostatic discharge (ESD) protection to ± 8 kV using IEC1000-4-2 Contact Discharge and ±15 kV using the Human Body Model. ST3222E has a proprietary low dropout transmitter output stage providing true RS-232 performance from 3 to 5 V supplies with a dual charge pump. The charge pump requires only four small 0.1 mF external capacitors for operation form 3 V supply. The device has two receivers and two drivers. The ST3222E features a 1 mA shutdown mode that reduces power consumption and extends battery life in portable systems. Its receivers can remain active in shutdown mode, allowing external devices such as modems to be monitored using only 1 mA supply current. The device is guaranteed to run at data rates of 250 Kbps while maintaining RS-232 output levels.

TSSOP

SSOP

Typical applications are Notebook, Sub-notebook and Palmtop Computers, Battery Powered Equipment, Hand-Held Equipment, Peripherals and Printers.

	Table 1.	Device summary
	Order codes		Temperature	Package	Packaging
			range
	ST3222ECPR		0 to 70 °C	SSOP20 (tape and reel)	1350 parts per reel
	ST3222EBPR		-40 to 85 °C	SSOP20 (tape and reel)	1350 parts per reel
	ST3222ECTR		0 to 70 °C	TSSOP20 (tape and reel)	2500 parts per reel
	ST3222EBTR		-40 to 85 °C	TSSOP20 (tape and reel)	2500 parts per reel
	January 2008			Rev 8	1/15

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Contents	ST3222E

Contents

1	Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 3
2	Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	4
3	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
4	Application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
5	Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
6	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	9
7	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	14

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ST3222E	Pin configuration

1 Pin configuration

Figure 1. Pin connection

	Table 2.	Pin description
	Pin n°	Symbol	Name and function
	1	EN	Receiver enable control. drive low for normal operation. Drive high to force the
			receivers outputs (R_OUT) into a high-impedance state.
	2	C1+	Positive terminal for the first charge pump capacitor
	3	V+	5.5V Generated by the charge pump.
	4	C1-	Negative terminal for the first charge pump capacitor
	5	C2+	Positive terminal for the second charge pump capacitor
	6	C2-	Negative terminal for the second charge pump capacitor
	7	V-	-5.5V Generated by the charge pump.
	8	T2OUT	Second transmitter output voltage
	9	R2IN	Second receiver input voltage
	10	R2OUT	Second receiver output voltage
	11	NC	Not connected
	12	T2IN	Second transmitter input voltage
	13	T1IN	First transmitter input voltage
	14	NC	Not connected
	15	R1OUT	First receiver output voltage
	16	R1IN	First receiver input voltage
	17	T1OUT	First transmitter output voltage
	18	GND	Ground
	19	VCC	Supply voltage
	20	SHDN	Active low shutdown control input. drive low to shut-down transmitter and charge pump
			3/15

Absolute maximum ratings			ST3222E
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	(VCC - 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
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
tSHORT	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 (VCC, then V+, then V-) is critical, therefore it is not recommended to use this device using externally applied voltage to V+ and V-.

Table 4.	Shutdown and enable control truth table
	SHDN	EN		T-OUT	R-OUT
	0	0		High Z	Active
	0	1		High Z	High Z
	1	0		Active	Active
	1	1		Active	High Z

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	±8			kV

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ST3222E	Electrical characteristics

3 Electrical characteristics

Table 6. 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	No load,			= VCC, TA = 25°C		0.3	1	mA
				SHDN
ISHDN	Shutdown supply current	No load,			= VCC, TA = 25°C		1	10	µA
			SHDN

Table 7.	Logic input 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
VIL	Input logic threshold low	T-IN,				(Note: 1)				0.8	V
			EN,		SHDN
VIH	Input logic threshold high	VCC = 3.3 V					2				V
		VCC = 5 V					2.4
VHYS	Transmitter input							0.25			V
	hysteresis
IIL	Input leakage current	T-IN,						± 0.01		± 1	µA
			EN,		SHDN
Note: 1	Transmitter input hysteresis is typically 250 mV
Table 8.	Transmitter 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
VTOUT	Output voltage swing	All transmitter outputs are loaded with					± 5	± 5.4			V
		3 KΩ to GND
RTOUT	Transmitter output	VCC = V+ = V- = 0 V, VOUT = ± 2 V					300	10M			Ω
	resistance
ITSC	Output short circuit							± 60			mA
	current
ITOL	Output leakage current	VCC = 0 or 3 V to 3.6 V, VOUT = ± 12 V								± 25	µA
		Transmitters disable

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