ST ST3293 User Manual

ST3293

ST3293

RS-422 HIGH SPEED TRANSCEIVER

WITH DIGITAL EMPHASIS

■FULL DUPLEX COMMUNICATIONS DEVICE RS-422

■PROGRAMMABLE EMPHASIS INCREASES THE DISTANCE AND DATA RATE

■HIGH SPEED: DATA RATE UP TO 25Mbps

■-7V TO 7V COMON-MODE INPUT VOLTAGE RANGE

■LVTTL LOGIC INPUT THRESHOLDS

DESCRIPTION

The ST3293 is a high-speed RS-422 transceiver with an emphasis circuitry on the driver which allows reliable long distance communication at high data rate by reducing inter symbolic interference. The differential amplitude of the ST3293 is digitally programmable in 7 steps through 3 control pins. The emphasis reduces the inter symbolic interference by increasing the signal amplitude under the micro control and counteracting the effects of the cable with the varying data stream. The ST3293 is a full duplex device that operates from a single +5V supply. It

SOP

features driver output short circuit current limiting and an open circuit fail-safe receiver input. The PE input can be used as an emphasis enable. The PE held LOW disable the emphasis instead set to HIGH enable the emphasis with the configuration on C0, C1 and C2 when DI change logic level. The DI input can direct drive the outputs with a fixed emphasis or without emphasis as shown in the timing diagram.

ORDERING CODES

	Type	Temperature	Package	Comments
		Range
	ST3293BD	-40 to 85 °C	SO-14 (Tube)	50 parts per tube / 20 tube per box
	ST3293BDR	-40 to 85 °C	SO-14 (Tape & Reel)	2500 parts per reel

January 2003

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ST3293

PIN CONFIGURATION

PIN DESCRIPTION

PlN N°	SYMBOL	NAME AND FUNCTION
1	C0	Emphasis Control Input 0
2	C1	Emphasis Control Input 1
3	C2	Emphasis Control Input 2
4	PVCC	Supply Voltage
5	RO	Receiver Output
6	DI	Driver Input
7	PGND	Ground
8	Y	Non-inverting Driver Output
9	Z	Inverting Driver Output
10	B	Inverting Receiver Input
11	A	Non-inverting Receiver Input
12	PE	Emphasis Enable
13	LGND	Ground
14	LVCC	Supply Voltage

TRUTH TABLE

TRANSMITTING INPUTS

	INPUTS		OUTPUTS	EMPHASIS STATUS
PE		DI	PECTRL
L		X	L	Disabled
H		0->1	H	Enabled
H		1->0	H	Enabled

X= Don’t Care; Z=High Impedance

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							ST3293
EMPHASIS CONTROL INPUT
		INPUTS PE = HIGH			DRIVER EMPHASIS FACTOR (DEF)
C0		C1		C2		RL = 100 Ω
L		L		L	1.0
L		L		H	1.1
L		H		L	1.2
L		H		H	1.3
H		L		L	1.4
H		L		H	1.5
H		H		L	1.6
H		H		H	1.7
ABSOLUTE MAXIMUM RATINGS
Symbol		Parameter				Value		Unit
VCC	Supply Voltage					-0.5 to 7		V
C0, C1,	Control Input Voltage					-0.5 to 7		V
C2, DI, PE
Y, Z	Driver Output Voltage VCC = 0V or VOUT = Z-state					-0.5 to 7		V
A, B	Receiver Input Voltage					-14 to 14		V
RO	Receiver Output Voltage					-0.5 to (VCC + 0.5)		V
PD	Continuous Total Power Dissipation (SO-14)					0.5		W
TJ	Operating Junction Temperature Range					-40 to 150		°C
Tstg	Storage Temperature Range					-65 to 150		°C
ESD	Human Boby Model (Receiver Inputs vs GND)					±1		KV

Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied.

RECOMMENDED OPERATING CONDITIONS

Symbol	Parameter	Test Conditions	Min.	Typ.	Max.	Unit
VCC	Supply Voltage		4.75		5.25	V
VIH	High Level Logic Input Voltage	C0, C1, C2, DI, PE	2		VCC	V
VIL	Low Level Logic Input Voltage	C0, C1, C2, DI, PE	0		0.8	V
IIN	Input Current of Logic Input	C0, C1, C2, DI, PE			±2	µA
ICC	Supply Current	No Load			4	mA
TA	Operating Temperature Range		-40		85	°C

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ST3293

DRIVER ELECTRICAL CHARACTERISTICS

(VCC = 5V ± 5%, -40°C < T A < 85°C, unless otherwise noted. Typical values are referred to T a = 25°C)

Symbol	Parameter	Test Conditions	Min.	Typ.	Max.	Unit
|VOD|	Differential Output Voltage	No Load	2		VCC	V
|VOD1|	Differential Output Voltage	R = 100 Ω, PE = Low	2	2.32	2.8	V
	without Emphasis
DPER	Differential Output	See Truth Table	0.9		1.1
	Emphasis Step Precision
DEF	Differential Output	See Truth Table	1		2
	Emphasis Factor
|VOPD|	Differential Driver Output	R = 100 Ω, DEF = 1.1		2.52		V
	with Emphasis	R = 100 Ω, DEF = 1.7		3.85
VOD	Change in Magnitude of	R = 100 Ω, All DEF values	-0.2	0	0.2	V
	Differential Output Voltage
VOC	Driver Common-Mode	R = 100 Ω, All DEF values	1	VCC/2	3.5	V
	Output Voltage
VOC	Change in Magnitude of	R = 100 Ω	-0.2	0	0.2	V
	Common Mode Output
	Voltage
IOFF	Output Leakage Current	VCC = GND VO = 6V		0.1	±100	μA
	(Y and Z)
IOSD	Driver Short Circuit Output	VO = 0V,	-30	-50	-150	mA
	Current	C0 = C1 = C2 = 0

RECEIVER DC ELECTRICAL CHARACTERISTICS

(VCC = 5V ± 5%, -40°C < T A < 85°C, unless otherwise noted. Typical values are referred to T a = 25°C)

Symbol	Parameter	Test Conditions	Min.	Typ.	Max.	Unit
VTH	Receiver Differential	-7V ≤ VCM ≤ 7V	-200		200	mV
	Threshold Voltage
VHYST	Receiver Input Hysteresis	VCM = 0V		50		mV
VOL	Low Level Output Voltage	IOL = 4mA	GND	0.2	0.4	mV
VOH	High Level Output Voltage	IOH = -4mA	3.7	4.7	VCC	mV
IIN	Input Current	VIN=10V, Other Input = GND		0.32	1.5	mA
		VIN=10V, Other Input = GND		-0.5	-2.5
RIN	Receiver Input Resistance	-7V ≤ VCM ≤ 7V, VCC = 0V	12	24		KΩ

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