UC17131/2/3
UC27131/2/3
UC37131/2/3

SLUS340 - APRIL 1999

FEATURES

300mA Continuous Output Current

Low Side or High Side Switch
Configuration

8V to 65V Operation

Overload and Short Circuit Protection

Power Interruption Protection

+6V Regulated Voltage

2mA Quiescent Current

Programmable Overcurrent and
Power Interruption Protection

1% to 30% Programmable Input
Comparator Hysteresis (on UC37132)

Low and High Side Internal High
Current Clamps When Driving
Inductive Loads

Smart Power Switch

VREF

VCC

CSH

CSL

GND

PRE-REGULATOR

INPUT
COMPARATOR

1/2
VREF

HYST

LED

TURN-ON/OFF

AND

SHORT CIRCUIT

PROTECTION

OUT

72V

6V/8mA

CDEL

UC37132 BLOCK DIAGRAM

UDG-98026

DESCRIPTION

The UC37131, UC37132 and UC37133 are a family of smart power
switches which can drive resistive or inductive loads from the high side or
low side.

The UC37132 is available in 14 pin (DIP), 16 pin (SOIC), or 20 pin (CLCC)
packages and can accommodate both low side (load to VCC) or high side
(load to GND) configurations. The UC37131 and UC37133 are exclusively
for a low side or a high side configuration respectively and both are avail-
able in an 8 pin package. Both high side and low side configurations provide
high current switching with low saturation voltages which can drive resistive
or inductive loads.

The input to the switch is driven by a low voltage signal, typically 5V. Addi-
tionally, UC37132 features adjustable hysteresis. The output of the device
can switch a load between 8V and 65V. Output current capability is 300mA
continuous or 700mA peak.

The device also has inherent smart features that allow for programmable
turn-on delay in enabling the output following startup. The same capacitor
that specifies the turn-on delay is also used to program a VCC power inter-
ruption time. If VCC drops below a threshold for a time specified by this ca-
pacitor, the output is turned off and a new turn-on delay will be re-triggered.
Similarly, if high current persists longer than the response delay, the output
driver will operate in a very low duty cycle mode to protect the IC.

UC17131/2/3
UC27131/2/3
UC37131/2/3

CSH

VCC

GND

CDEL

LED

VREF

ABSOLUTE MAXIMUM RATINGS

VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65V
LS HS (Clamped by internal circuitry) . . . . . . . . . . . . . . . 78V
CSH, LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65V
Output Current

Continuous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400mA
Peak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 900mA

Remaining Pin Voltages . . . . . . . . . . . . . . . . . . . . . 0.3V to 9V
Storage Temperature . . . . . . . . . . . . . . . . . . .

65°C to +150°C

Junction Temperature . . . . . . . . . . . . . . . . . . . 55°C to +150°C
Lead Temperature (Soldering, 10 sec.) . . . . . . . . . . . . . +300°C

Currents are positive into, negative out of the specified termi-
nal. Consult Packaging Section of Databook for thermal limita-
tions and considerations of packages.

PART

NUMBER

CONFIGURATIONS

PACKAGE

PIN COUNT

UCX7131

Low Side Only

UCX7132

Low Side or High Side

14, 16, 20

UCX7133

High Side Only

PRODUCT SELECTION TABLES

PART

NUMBER

TEMPERATURE

RANGE

AVAILABLE
PACKAGES

UC1713X

55°C to +125°C

J, L

UC2713X

40°C to +85°C

D, N

UC3713X

0°C to +70°C

D, N

HYST

N/C

VREF

CDEL

N/C

LED

GND

N/C

CSH

VCC

CSL

VCC

GND

CDEL

LED

VREF

HYST

N/C

VREF

CDEL

N/C

LED

N/C

GND

N/C

VCC

CSH

N/C

CSL

CONNECTION DIAGRAMS

SOIC-16 (Top View)
(for UCX7132)
D Package

N/C

20 19

12 13

CSH

CSL

N/C

GND

N/C

VCC

N/C

HYST

VREF

CDEL

N/C

LED

PLCC-20 (Top View)
(for UCX7132)
L Packages

DIL-14 (Top View)
(for UCX7132)
J, or N Packages

DIL-8, SOIC-8 (Top View)
(for UCX7131)
J, N, or D Packages

DIL-8, SOIC-8 (Top View)
(for UCX7133)
J, N, or D Packages

UC17131/2/3
UC27131/2/3
UC37131/2/3

ELECTRICAL CHARACTERISTICS

Unless otherwise specified, CDEL = 10nF, VCC = 25V, CSL = GND, CSH = LS;

CSH

= 0.5

(Note 1); IN=0V (for OFF condition) and IN=5V (for ON condition); T

= T

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Reference

VREF

25°C

5.8

6.2

55°C to 125°C

5.6

6.4

Line Regulation

VCC = 8V to 64V

Load Regulation

0 < I

REF

< 8mA

Short Circuit Current

REF = 0V

Input Comparator

Turn-On Threshold Voltage

2.7

3.3

Input Bias Current

= 3.5V

Hysteresis

HYST

= GND (Internally for X31, X33)

0.775

0.9

1.025

HYST

= 96.67k for (X32)

Output: High Side (UCX7133: CSH = LS and CSL = GND Internally; See Fig. 2a)

Rise Time (Off to On)

LOAD

= 250

to GND

Fall Time (On to Off)

LOAD

= 250

to GND

Output Short Circuit

HS = 0.25

to GND

500

900

Voltage Clamp

LSHS

Saturation Voltage

25°C, R

LOAD

= 100

to GND

1.2

40°C, R

LOAD

= 100

to GND

1.3

55°C, R

LOAD

= 100

to GND

1.4

Leakage Current

Output: Low Side (UCX7131; CSH = VCC and CSL = HS Internally; See Fig. 2b)

Rise Time (On to Off)

LOAD

= 250

to VCC, R

CSL

= 0.5

Fall Time (Off to On)

LOAD

= 250

to VCC, R

CSL

= 0.5

Output Short Circuit

LS = 0.25

to VCC

500

700

900

Voltage Clamp

LSHS

Saturation Voltage

25°C, R

LOAD

= 100

to VCC, R

CSL

= 0.5

1.2

40°C, R

LOAD

= 100

to VCC, R

CSL

= 0.5

1.3

55°C, R

LOAD

= 100

to VCC, R

CSL

= 0.5

1.4

Leakage Current

VCC Fault Section

Output Turn-On Delay, t

D(ON)

Step VCC from 0V to 8V (See Fig. 3a)

9.5

13.5

Output Turn-Off Delay, t

D(OFF)

Pulse VCC from 25V to VCC Turn-Off
Threshold

300

500

700

VCC Turn-Off Threshold

Pulse VCC Low

6.5

7.5

CDEL Section

CDEL_MAX

5.8

FAULT_H

4.9

FAULT_L

1.0

Overcurrent Fault Section (See Fig. 3c)

Short Circuit Turn-Off Delay, t

Step I

LOAD:

0mA to 400mA

Short Circuit Recovery Time, t

ROFF

LOAD

= 400mA, 100

High Side Current Threshold, I

TH-H

CSH

= 0.5

250

325

400

Low Side Current Threshold, I

TH-L

CSL

= 0.5

250

325

400

Overcurrent Duty Cycle

LOAD

= 0.25

to GND

0.6

0.8

1.0

UC17131/2/3
UC27131/2/3
UC37131/2/3

ELECTRICAL CHARACTERISTICS

Unless otherwise specified, CDEL = 10nF, VCC = 25V, CSL = GND, CSH = LS;

CSH

= 0.5

(Note 1); IN=0V (for OFF condition) and IN=5V (for ON condition); T

= T

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

LED Output

SINK

, t

DOFF

, t

ROFF

LED

= 7V

5.0

8.0

11.0

LEAKAGE

Overall

Delay to Output

ICC

Output Off

2.0

2.8

= 1mA, 250mA (High Side)

2.3

= 1mA, 250mA (Low Side)

2.5

Note 1: All test conditions are for a high side configuration as in Fig. 2a, unless otherwise specified.

CDEL: A capacitor connected to this pin is used to pro-
gram both VCC pulse interruption time and power
turn-on delay. The capacitor discharge time corresponds
to VCC interruption and the charge time to VCC turn-on
delay. The ratio between turn-on delay and turn-off delay
will be fixed based on internal charge and discharge cur-
rents and voltage thresholds.

The same fault circuitry and capacitor is used for short
circuit and overload protection. If an overcurrent or short
circuit is detected, the capacitor starts charging and
turns off the output if the condition persists at the end of
its charge time. The output will then operate in a low-duty
cycle mode to protect the IC. After short circuit recovery,
the output will be reactivated in order to check if the short
circuit was removed. If the overcurrent persists the chip
will continue in this pulsing mode.

CSH: (For UC37132 and UC37133) This high side cur-
rent sense pin is used to program the current limit for
high side applications by connecting a resistor between
VCC and CSH. An over load current is detected when
the voltage drop between VCC and CSH exceeds
150mV. For the UC37132, in a high side application, the
CSH pin must be tied to the LS pin; in a low side applica-
tion, the CSH pin must be tied to VCC

CSL: (For UC37131 and UC37132) This low side cur-
rent sense pin is used to program the current limit for low
side applications by connecting a resistor between CSL
and GND. An over load current is detected when the volt-
age drop between CSL and GND exceeds 150mV. For
the UC37132, in a high side application, the CSL pin
must be tied to GND; in a low side application, the CSL
pin must be tied to the HS pin.

GND: The reference point for the internal reference, all
thresholds, and the return for the remainder of the de-
vice.

HS: (For UC37132 and UC37133) The output of the
switching transistor in the high side configuration. The
emitter of the output transistor is the HS pin which is con-
nected to the load. For the UC37132, the HS pin must be
tied to the CSL pin in a low side application.

HYST: (For UC37132) The pin used to program the in-
put comparator hysteresis by connecting a resistor to
ground. The hysteresis defaults to 30% with HYST
grounded (internally for UC37131 and UC37133).

HYST

3000

3330

(

)

IN: The input to the comparator that detects when the
output transistor should be turned on. The input thresh-
old is 3.0V (1/2 VREF) and the input voltage range is 0V
to VREF.

LED: Open collector output intended to drive an LED.
This pin is driven low whenever the output is turned off
and is externally pulled high when the output is turned on
(see Fig. 3b and 3c).

LS: (For UC37131 and UC37132) The output of the
switching transistor in the low side configuration. The col-
lector of the output transistor is the LS pin which is con-
nected to the load. For the UC37132, the LS pin must be
tied to the CSH pin in a high side application.

VREF: The 6V regulated reference capable of supplying
up to 8mA. The recommended decoupling capacitor is
1nF.

VCC: The supply voltage for the chip. Decouple this pin
with a good quality ceramic capacitor to ground.

PIN DESCRIPTIONS

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: UC17132

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: UC17132