Texas Instruments UC3544N, UC3544J, UC3544DWTR, UC3544DW, UC3543J Datasheet

UC1543 UC1544

UC2543 UC2544

UC3543 UC3544

Power Supply Supervisory Circuit

FEATURES

∙Includes Over-voltage, Under-voltage, And Current Sensing Circuits

∙Internal 1% Accurate Reference

∙Programmable Time Delays

∙SCR “Crowbar” Drive Of 300mA

∙Remote Activation Capability

∙Optional Over-voltage Latch

∙Uncommitted Comparator Inputs For Low Voltage Sensing (UC1544 Series Only)

BLOCK DIAGRAM

DESCRIPTION

The monolithic integrated circuits contain all the functions necessary to monitor and control the output of a sophisticated power supply system. Over-voltage (O.V.) sensing with provision to trigger an external SCR “crowbar” shutdown; an undervoltage (U.V.) circuit which can be used to monitor either the output or to sample the input line voltage; and a third op amp/comparator usable for current sensing (C.L.) are all included in this IC, together with an independent, accurate reference generator.

Both overand under-voltage sensing circuits can be externally programmed for minimum time duration of fault before triggering. All functions contain open collector outputs which can be used independently or wire-or’ed together, and although the SCR trigger is directly connected only to the over-voltage sensing circuit, it may be optionally activated by any of the other outputs, or from an external signal. The O.V. circuit also includes an optional latch and external reset capability.

The UC1544/2544/3544 devices have the added versatility of completely uncommitted inputs to the voltage sensing comparators so that levels less than 2.5V may be monitored by dividing down the internal reference voltage. The current sense circuit may be used with external compensation as a linear amplifier or as a highgain comparator. Although nominally set for zero input offset, a fixed threshold may be added with an external resistor. Instead of current limiting, this circuit may also be used as an additional voltage monitor.

The reference generator circuit is internally trimmed to eliminate the need for external potentiometers and the entire circuit may be powered directly from either the output being monitored or from a separate bias voltage.

Note: For each terminal, first number refers to 1543 series, second to 1544 series. * On 1543 series, this function is internally connected to VREF.

4/97

UC1543 UC1544

UC2543 UC2544

UC3543 UC3544

ABSOLUTE MAXIMUM RATINGS

Input Supply Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40V Sense Inputs, Voltage Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to VIN SCR Trigger Current (Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -600mA Indicator Output Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40V Indicator Output Sink Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA Power Dissipation (Package Limitation). . . . . . . . . . . . . . . . . . . . . . . 1000mW Operating Temperature Range

UC1543, UC1544 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55°C to +125°C UC2543, UC2544 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -25°C to +85°C UC3543, UC3544 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . -65°C to +150°C

Note 1: At higher input voltages, a dissipation limiting resistor, RG, is required. Note 2: Currents are positive-into, negative-out of the specified terminal. Consult Packaging section of Databook for thermal limitations and considerations of package.

CONNECTION DIAGRAMS

DIL-16, SOIC-16 (TOP VIEW)											UC 1543
J or N, DW Package											UC 2543
											UC 3543

PLCC-20, LCC-20	PACKAGE PIN FUNCTION
(TOP VIEW)	FUNCTION	PIN
Q or L Package	N/C	1
	SCR Trigger	2
	Remote Activate	3
	Reset	4
	O.V. Indicate	5
	N/C	6
	O.V. Delay	7
	O.V. Input	8
	N/C	9
	N/C	10
	U.V. Input	11
	U.V. Delay	12
	U.V. Indicate	13
	C.L. INV. Input	14
	C.L. N.I. Input	15
	Offset/Comp	16
	C.L. Output	17
	Ground	18
	VREF	19
	VIN	20

DIL-18, SOIC-18 (TOP VIEW)									UC 1544
J or N, DW Package									UC 2544
									UC 3544

PLCC-20, LCC-20	PACKAGE PIN FUNCTION
(TOP VIEW)	FUNCTION	PIN
Q or L Package	N/C	1
	SCR Trigger	2
	Remote Activate	3
	Reset	4
	O.V. Indicate	5
	N/C	6
	O.V. Delay	7
	O.V. N.I. Input	8
	O.V. INV. Input	9
	U.V. N.I. Input	10
	U.V. INV. Input	11
	U.V. Delay	12
	U.V. Indicate	13
	C.L. INV. Input	14
	C.L. N.I. Input	15
	Offset/Comp	16
	C.L. Output	17
	Ground	18
	VREF	19
	VIN	20

2