Texas Instruments UC3904N, UC3904DWTR, UC3904DW, UC2904J, UC2904DW Datasheet

UC1904

UC2904

UC3904

Precision Quad Supply and Line Monitor

FEATURES

∙Inputs for Monitoring Up to Four Supply Voltages

∙Two Inputs Preset for -5V and -12V Monitoring, or Programmable Positive Levels

∙Precision 2.5V Reference

∙Separate Inputs for Over-Current and Line Fault Sensing

∙Adjustable Underto Over-Voltage Fault Windows

∙Latched Over-Voltage and Over-Current Output

∙Power Good and Power Warning Outputs

∙Auto Restart Function with ON/OFF Control, and Programmable Delay

∙Programmable Pwr On Reset Delay

BLOCK DIAGRAM

DESCRIPTION

The UC1904 Quad Supply Monitor will respond to underand over-volt- age conditions on up to four continuously monitored voltage levels. Four independent positive voltages can be monitored or, alternatively, two of the sense inputs are preset to monitor -5V and -12V supplies. The device also monitors Over-Current and Line Sense inputs, both with precision input thresholds.

Four open collector outputs on the UC1904 give the following responses: 1. The OV/OC output is a latched over-voltage, or over-current response. 2. A Power Good signal responds low with any fault detection

– on power-up a programmable delay is used to hold this output low for a system Power On Reset signal. 3. The PWRW output responds only to a Line Sense input, for early warning of power failures. 4. The last open collector, the ON/OFF output, generates a delayed supply OFF control signal in response to an OFF input command, under-voltage condition, or line fault detection.

The OV-UV fault window is adjustable with a programming input. The thresholds are centered around the precision 2.5V reference, with a scaled hysteresis for precise, glitch free operation. In the positive mode of operation, the fault windows at each of the sense inputs can be independently scaled using external resistors and the 2.5V reference output. An Auto Restart function couples with the under-voltage and line sensing circuits to allow controlled power supply start-up and shutdown.

This device will operate over a supply range of 4.75V to 18V. The device is available in a DIP, SOIC, or PLCC outline. This device is ESD protected on all pins.

Note: Pin Numbers refer to J, N, and DW Packages.

4/97

ABSOLUTE MAXIMUM RATINGS (Note 1)

Input Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V Sense Inputs, S1 And S2, Other Analog And Logic Inputs

Maximum Forced Voltage . . . . . . . . . . . . . . . . . . -0.3V to 10V Maximum Forced Current . . . . . . . . . . . . . . . . . . . . . . ±10mA

Sense Input S3, (-12V Sense Input)

Maximum Forced Voltage . . . . . . . . . . . . . . . . . . -18V to 10V Maximum Forced Current . . . . . . . . . . . . . . . . . . . . . . ±10mA

Sense Input S4, (-5V Sense Input)

Maximum Forced Voltage . . . . . . . . . . . . . . . . . . -10V to 10V Maximum Forced Current . . . . . . . . . . . . . . . . . . . . . . ±10mA

Open Collector Outputs

Maximum Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V Maximum Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA Reference Output Current . . . . . . . . . . . . . . . Internally Limited Operating Junction Temperature . . . . . . . . . . . -55°C to +150°C Storage Temperature . . . . . . . . . . . . . . . . . . . . -65°C to +150°C

DIL-18, SOIC-18 (TOP VIEW)

J or N PACKAGE, DW PACKAGE

UC1904

UC2904

UC3904

Note 1: Unless otherwise indicated, voltages are reference to ground and currents are positive into, negative out of, the specified terminals.

CONNECTION DIAGRAMS

PLCC-20 (TOP VIEW)	PACKAGE PIN FUNCTION
Q PACKAGE
	FUNCTION	PIN
	2.5V	1
	POR DLY	2
	N.C.	3
	S1	4
	S2	5
	S3	6
	S4	7
	N.C.	8
	LS Input	9
	OC Input	10
	PWRW Out	11
	PG Out	12
	OV/OC Out	13
	VIN	14
	ON/OFF Out	15
	OFF DLY	16
	ON/OFF Input	17
	ARST Input	18
	WADJ	19
	Gnd	20

ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications hold for TA = 0 to 70°C for the
	UC3904, -40 to +85°C for the UC2904, and -55 to +125°C for the UC1904, +VIN =
	15V, WADJ = 0.5V, Sense Inputs 1-4, OC and LS Inputs = 2.5V. The ON/OFF Input
	and the ARST Input = 0V.
PARAMETER		TEST CONDITIONS		MIN	TYP	MAX	UNITS
Input Supply
VIN Supply Current	VIN = 15V				3.2	4.5	mA
VIN UVLO Threshold	Low to High				4.5	4.75	V
UVLO Threshold Hysteresis					50		mV
Minimum VIN to Enable PG Out					0.8	1.5	V
Reference
Output Voltage(VREF)	TJ = 25°C			2.475	2.5	2.525	V
	Over Temperature, UC3904			2.47		2.53	V
	Over Temperature, UC2904 & UC1904			2.465		2.535	V
Load Regulation	IOUT = 0 to 4mA					6	mV
Line Regulation	VIN = 4.75 to 18V					5	mV
Short Circuit Current	VREF = 0V				17		mA
OV UV Window, LS Input, OC Input, ARST Input, and		ON/OFF Input Thresholds
Over-Voltage Thresholds	WADJ = 0.25V, Offset from VREF, Input L to H			110	125	140	mV
S1, S2	WADJ = 0.5V, Offset from VREF, Input L to H			230	250	270	mV
	WADJ = 1V, Offset from VREF, Input L to H			460	500	540	mV
Over-Voltage Thresholds	WADJ = 0.25V, Offset from VREF, Input L to H			110	125	145	mV
S3, S4 Positive Mode	WADJ = 0.5V, Offset from VREF, Input L to H			230	250	280	mV
	WADJ = 1V, Offset from VREF, Input L to H			460	500	550	mV

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