UC3543DWTR - Texas Instruments

Power Supply Supervisory Circuit

•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)

The monolithic integrated circuits contain all the functions necessary to monitor

and control the output of a sophisticated power supply sy stem. Over-voltage (O.V.)

sensing with provision to trigger an external SCR “crowbar” shutdown; an under-

voltage (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 a ll include d in this IC, together with an independent, acc urate r eference

generator.

Both over- and under-voltage sensing circuits can be externally programmed for

minimum time du ration of fault before tri gger ing. All functions contain open collec-

tor 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 o pt io nally act ivate d by any of the other outputs, or fr om 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 uncom-

mitted inputs to the voltage s ensin g c om parators so that levels less than 2.5V may

be monitored by dividing down the internal reference voltage. The current sense

circu it may be used wi th exter nal compen satio n as a line ar amplifier or as a high-

gain 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 ex-

terna l potentiometers and the entire circuit may be powered directly from either the

output being monitored or from a separate bias voltage.

BLOCK DIAGRAM

Note: For each terminal, firs t n um be r refers to 1543 series, second to 15 44 series.

* On 1543 series, this function is internally connected to V

REF.

UC1543 UC1544

UC2543 UC2544

UC3543 UC3544

DESCRIPTIONFEATURES

4/97

ABSOLUTE MAXIMUM RATINGS

Input Supply Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40V

Sense Inputs, Voltage Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to VIN

SCR Trigger Current (Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -600mA

Indicator Ou tput Vol tage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 V

Indicator Ou tput Sink Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA

Power Dissipation (Package Limitation). . . . . . . . . . . . . . . . . . . . . . . 1000mW

Operating Tempera tu r e Ran ge

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 in put voltages, a dissipation limiting resi stor, RG, is r equired.

Note 2: Currents are positive-into, negative-out of the spec ified terminal . Con-

sult Packaging section of Databook for thermal limitations and considerations

of packa ge.

UC1543 UC1544

UC2543 UC2544

UC3543 UC3544

CONNECTION DIAGRAMS

DIL-16, SOIC-16 (T OP VIEW)

J or N, DW Package UC 1543

UC 2543

UC 3543

DIL-18, SOIC-18 (T OP VIEW)

J or N, DW Package UC 1544

UC 2544

UC 3544

PACKAGE PIN FUNCTION

FUNCTION PIN

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. Indi cate 13

C.L. INV. Input 14

C.L. N.I. In put 15

Offset/Comp 16

C.L. Output 17

Ground 18

VREF 19

VIN 20

PLCC-20, LCC-20

(T OP VIEW)

Q or L Package

PACKAGE PIN FUNCTION

FUNCTION PIN

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. Indi cate 13

C.L. INV. Input 14

C.L. N.I. In put 15

Offset/Comp 16

C.L. Output 17

Ground 18

VREF 19

VIN 20

PLCC-20, LCC-20

(TOP VIEW)

Q or L Package

PARAMETER TEST CONDITIONS UC1543/UC1544

UC2543/UC2544 UC3543/UC3544 UNITS

MIN TYP MAX MIN TYP MAX

Input Voltage Range TJ = 25°C to TMAX 4.5 40 4.5 40 V

TMIN to TMAX 4.7 40 4.7 40 V

Supply Current VIN = 40V, Output Open, TJ = 25°C 7 10 7 10 mA

TMIN ≤ TJ ≤ TMAX 15 15 mA

Reference Section

Output Voltage TJ = 25°C 2.48 2.50 2.52 2.45 2.50 2.55 V

Output Voltage Over Temperature Range 2.45 2.55 2.40 2.60 V

Line Regulation VIN = 5 to 30V 1 5 1 5 mV

Load Regulation IREF = 0 to 10m A 1 10 1 10 mV

Short Circui t Curre nt VREF = 0 -10 -20 -40 -12 -20 -40 mA

Temperature Stability 50 50 ppm/°C

SCR Trigger Section

Peak Output Curre nt VIN = 5V, RG = 0, VO = 0 -100 -300 -600 -100 -300 -600 mA

Peak Output Voltage VIN = 15V, IO = -10 0m A 12 13 12 13 V

Output Off Voltage VIN = 40V 0 0.1 0 0.1 V

Remote Activate Current R/A Pin = Gnd -0.4 -0.8 -0.4 -0.8 mA

Remote Activate Voltage R/A Pin Open 2 6 2 6 V

Reset Current Reset = Gnd, R/A = Gnd -0.4 -0.8 -0.4 -0.8 mA

Reset Voltage Reset open, R/A = Gnd 2 6 2 6 V

Output Current Rise Time RL = 50Ω, TJ = 25°C, CD = 0 400 400 mA/µs

Prop. Delay from R/A RL = 50Ω, TJ = 25°C, CD = 0 300 300 ns

Prop. Delay from O/V input RL = 50Ω, TJ = 25°C, CD = 0 500 500 ns

Comparator Section

Input Thres hold (Inp ut

volt age rising on O.V. and

fallin g on U.V.)

TJ = 25°C 2.45 2.50 2.55 2.40 2.50 2.60 V

Over Temperature R ange 2.40 2 .60 2.35 2 .65 V

Input H ys te res is 25 25 mV

Input Bia s Curre nt Sense Input = 0V -0.3 -1.0 -0.3 -1.0 µA

Delay Saturation 0.2 0.5 0.2 0.5 V

Delay High Level 6 7 6 7 V

Delay Charging Current VO = 0 -200 -250 -300 -200 -250 -300 µA

Indicate Saturation IL = 10mA 0.2 0.5 0.2 0.5 V

Indicate Leakage VIND = 40V .01 1.0 .01 1.0 µA

Propagation Delay Input Over Drive = 200mV, TJ = 25°C, C D = 0 400 400 ns

Input Over Drive = 200mV, TJ = 25°C, CD = 1µF10 10 ms

Current Limit Section

Input Voltage Range 0 VIN -3V 0 VIN -3V V

Input Bia s Current Offset Pin Open, VCM = 0 -0.3 -1.0 -0.3 -1.0 µA

Input Offset Voltage Offset Pin Open, VCM = 0 0 10 0 10 mV

10kΩ from Offset Pin to Gnd 80 100 120 80 100 120 mV

CMRR 0 ≤ VCM ≤ 12V, VIN = 15V 6070 6070 dB

AVOL Offset Pin Open, VCM = 0V,

RL = 10k to 15kΩ, ∆VOUT = 1 to 6V 72 80 72 80 dB

Output Saturation IL = 10mA 0.2 0.5 0.2 0.5 V

Outpu t Le ak ag e VIND = 40V .01 1.0 .01 1.0 µA

Small Signal Bandwidth AV = 0dB, TJ = 25°C 5 5 MHz

Propagation Delay VOVERDRIVE = 100mV , TJ = 25° C 200 200 ns

ELECTRICAL CHARACTERISTICS: Unles s ot he rwis e stated, thes e sp ec ifications app ly for T A = -55°C to +125 °C for the

UC1543 an d UC15 4 4; -25°C to +85°C for the UC2543 and UC2544; and 0°C to +7 0°C for the UC3543 and UC3544. Electrica l

tests are performed with VIN = 10V and 2kΩ pull-up re sistors on all indicato r outputs. All electrical specificati ons for the UC1544,

UC2544, and UC3544 devices are tested with the inverting over-vo ltage input and the non-inverting under-voltage input externally

con nected to the 2.5V reference. TA = TJ.

UC1543 UC1544

UC2543 UC2544

UC3543 UC3544

UC1543 UC1544

UC2543 UC2544

UC3543 UC3544

Note: R

is connected from Offset Pin to Gnd. Values of

below 5.0k may cause Amplifier Cutoff at -55

SCR Trigger P o wer Limiting

Current Limit Amplifier Frequency Response

Activation Dela y vs Capacitor Value

Comparator Input Hysteresis

Current Limit Input Threshold

Current Limit Amplifier Gain

UNITRODE CORPO RATION

7 CONTINENTAL BLVD. • MERRIMACK, NH 03054

TEL. (603) 424-2410 • FAX 603-424-3460

UC1543 UC1544

UC2543 UC2544

UC3543 UC3544

Overcurrent ShutdownInput Line Monitor

APPLICATIONS (Pin numbers given for UC1543 series devices)

Typical Application

Sensing Multiple Supp ly Voltages

The values for the external components are determined

as follows:

Current limit input threshold, V

= 1000

is determined by the current loop dynamics

Peak current to load, I

≅







2 +

3





Short Circuit Current, I

= V

Low o utput v o ltage limi t, V

(Low) = 2.5

)

High output voltage limit, V

(High) = 2.5

)

Voltage sensing delay, t

= 10,000 C d

SCR trigger power limiting resistor, R

> V

−

0.2

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