Allegro A2557SLB, A2557SEB, A2557SB, A2557KLB, A2557KEB Datasheet

Data Sheet

29317.16E

2557

PROTECTED QUAD LOW-SIDE DRIVER

WITH FAULT DETECTION & SLEEP MODE

The A2557xB, A2557xEB, and A2557xLB have been specifically
designed to provide cost-effective solutions to relay-driving applications with
up to 300 mA drive current per channel. They may also be used for driving
incandescent lamps in applications where turn-on time is not a concern. Each
of the four outputs will sink 300 mA in the on state. The outputs have a
minimum breakdown voltage of 60 V and a sustaining voltage of 40 V. A
low-power Sleep Mode is activated with either ENABLE low or all inputs
low. In this mode, the supply current drops to below 100 µA.

Over-current protection for each channel has been designed into these
devices and is activated at a nominal 500 mA. It protects each output from
short circuits with supply voltages up to 32 V. When an output experiences a
short circuit, the output current is limited at the 500 mA current clamp. In
addition, foldback circuitry decreases the current limit if an excessive voltage
is present across the output and assists in keeping the device within its SOA
(safe operating area). An exclusive-OR circuit compares the input and output
state of each driver. If either a short or open load condition is detected, a
single FAULT output is turned on (active low). Similar devices, for operation
to 1.3 A, are available as the UDx2547B/EB.

Continuous or multiple overload conditions causing the channel tempera­ture to reach approximately 165°C will result in an additional linear decrease
in the output current of the affected driver. If the fault condition is corrected,
the output stage will return to its normal saturated condition.

The first character of the part number suffix determines the device
operating temperature range. Suffix ‘S-’ is the standard -20°C to +85°C;
suffix ‘E-’ is -40°C to +85°C; suffix ‘K-’ is for the industrial temperature
range of -40°C to +125°C. Package suffix ‘-B’ devices are 16-pin power
DIPs; suffix ‘-EB’ devices are 28-lead power PLCCs; and suffix ‘-LB’ are 16­lead power wide-body SOICs for surface-mount applications. All packages
are of batwing construction to provide for maximum package power dissipa­tion.

FEATURES

■ 300 mA Output Current per Channel

■ Independent Over-Current Protection &Thermal Limiting for Each Driver

■ Output Voltage to 60 V

■ Output SOA Protection

■ Fault-Detection Circuitry for Open or Shorted Load

■ Low Quiescent Current Sleep Mode

■ Integral Output Flyback/Clamp Diodes

■ TTL- and 5 V CMOS-Compatible Inputs

1

2

3

14

4

5

6

7

8

9

10

11

12

13

15

16

ENABLE

GROUND

GROUND

OUT

3

FAULT

GROUND

GROUND

OUT

2

OUT

1

K

OUT

4

V

CC

IN

4

Dwg. PP-017-4

IN

1

IN

2

IN

3

A2557xLB

Note that the A2557xB (DIP) and the A2557xLB
(SOIC) are electrically identical and share a
common terminal number assignment.

ABSOLUTE MAXIMUM RATINGS

Output Voltage, VO.............................. 60 V

Over-Current Protected Output Voltage,

VO..................................................... 32 V

Output Current, IO......................... 500 mA*

FAULT Output Voltage, V

FLT

............. 60 V

Logic Supply Voltage, VCC................. 7.0 V

Input Voltage, VI or VOE..................... 7.0 V

Package Power Dissipation,

PD........................................... See Graph

Operating Temperature Range, T

A

Suffix ‘S-’ ...................... -20°C to +85°C

Suffix ‘E-’ ...................... -40°C to +85°C

Suffix ‘K-’ ................... -40°C to +125°C

Junction Temperature,

TJ............................................... +150°C*

Storage Temperature Range,

TS................................. -55°C to +150°C

*Outputs are current limited at approximately
500 mA per driver and junction temperature
limited if higher current is attempted.

Complete part number includes a suffix to identify operating temperature

range (E-, K-, or S-) and package type (-B, -EB, or -LB). Always order by
complete part number, e.g., A2557KLB .

2557

PROTECTED QUAD DRIVER
WITH FAULT DETECTION
& SLEEP MODE

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

2

Copyright © 1998, 2000, Allegro MicroSystems, Inc.

FUNCTIONAL BLOCK DIAGRAM

<<1 Ω

OUT

Dwg. FP-007-2

N

ENABLE

IN

N

FAULT

COMMON CONTROL

ONE OF FOUR DRIVERS

CURRENT

LIMIT

THERMAL

LIMIT

SLEEP

CONTROL

30 µA

60 µA

2.5 V

–

+

K

V

CC

A2557xEB

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

GROUND

GROUND

GROUND

GROUND

Dwg. PP-019-2

NO

CONNECTION

ENABLE

SUPPLY

NC

NC

CC

V

OUT

1

OUT

2

OUT

3

OUT

4

IN

4

IN

3

IN

2

IN

1

NO

CONNECTION

K

FAULT

50 75 100 125 150

5

3

2

1

0

ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS

TEMPERATURE IN °C

4

25

R = 6°C/W

θJT

Dwg. GP-004-2A

SUFFIX 'EB', R = 36°C/W

θJA

SUFFIX 'B', R = 43°C/W

θJA

SUFFIX 'LB', R = 63°C/W

θJA

2557

PROTECTED QUAD DRIVER

WITH FAULT DETECTION

& SLEEP MODE

www.allegromicro.com

3

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Output Leakage Current* I

CEX

VO = 60 V, VI = 0.8 V, VOE = 2.0 V — 30 100 µA

VO = 60 V, VI = 2.0 V, VOE = 0.8 V — <1.0 100 µA

Output Sustaining Voltage V

O(SUS)

IO = 100 mA, VI = VOE = 0.8 V, V

CC

= Open 40 — — V

Output Saturation Voltage V

O(SAT)

IO = 100 mA — 65 200 mV

IO = 300 mA — 180 300 mV

Over-Current Limit I

OM

5 ms PulseTest, VO = 5.0 V — 500 — mA

Input Voltage V

IH

INn or ENABLE 2.0 — — V

V

IL

INn or ENABLE — — 0.8 V

Input Current I

IH

INn or ENABLE, VIH = 2.0 V — — 10 µA

I

IL

INn or ENABLE, VIL = 0.8 V — — -10 µA

Fault Output Leakage Current I

FLT

V

FLT

= 60 V — 4.0 15 µA

V

FLT

= 5 V — <1.0 2.0 µA

Fault Output Current I

FLT

V

FLT =

5 V, Driver Output Open,

VI = 0.8 V, V

OE

= 2.0 V 40 60 80 µ A

Fault Output Saturation Voltage V

FLT(SAT)

I

FLT

= 30 µA — 0.1 0.4 V

Clamp Diode Forward Voltage V

F

IF = 500 mA — 1.2 1.7 V

IF = 750 mA — 1.5 2.1 V

Clamp Diode Leakage Current I

R

VR = 60 V — — 50 µA

Turn-On Delay t

PHL

IO = 300 mA, 50% VI to 50% V

O

— 0.6 10 µs

From Sleep, IO = 300 mA, 50% VI to 50% V

O

— 3.0 — µs

IO = 300 mA, 50% VOE to 50% V

O

— 1.3 10 µs

Turn-Off Delay t

PLH

IO = 300 mA, 50% VI to 50% V

O

— 2.0 10 µs

IO = 300 mA, 50% VOE to 50% V

O

— 1.4 10 µs

Total Supply Current I

CC

All Outputs Off — 0.075 0.1 mA

Any One Output On — 12 20 mA

Two Outputs On — 18 30 mA

Three Outputs On — 24 40 mA

All Outputs On — 30 50 mA

Thermal Limit T

J

— 165 — °C

ELECTRICAL CHARACTERISTICS over operating temperature range, V

CC

= 4.75 V to 5.25 V

Typical Data is at TA = +25°C and VCC = 5 V and is for design information only.
Negative current is defined as coming out of (sourcing) the specified terminal.
As used here, -100 is defined as greater than +10 (absolute magnitude convention) and the minimum is implicitly zero.
* Measurement includes output fault-sensing pull-down current.

2557

PROTECTED QUAD DRIVER
WITH FAULT DETECTION
& SLEEP MODE

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

4

TYPICAL OPERATING CHARACTERISTICS

100

Dwg. GP-064

200

400

300

OUTPUT CURRENT IN MILLIAMPERES

0

0.3

0.2

OUTPUT SATURATION VOLTAGE IN VOLTS

0.1

0

VCC = 5 V

T

A

= 125

°C

T

A

= 25

°C

T

A

=

-4

0

°C

10

Dwg. GP-065

20

40

30

OUTPUT VOLTAGE IN VOLTS

0

600

500

400

300

OUTPUT CURRENT LIMIT IN MILLIAMPERES

TA = +25°C

V

CC

= 5 V

100

Dwg. GP-066-1

200

400

300

OUTPUT CURRENT IN MILLIAMPERES

0

3

2

TURN-ON DELAY IN MICROSECONDS

1

0

TA = +25°C

V

CC

= 5 V

ENABLE SWITCHING

IN SWITCHING (FROM SLEEP)

IN SWITCHING (AWAKE)

100

Dwg. GP-066

200

400

300

OUTPUT CURRENT IN MILLIAMPERES

0

6

4

TURN-OFF DELAY IN MICROSECONDS

2

0

TA = +25°C

V

CC

= 5 V

ENABLE SWITCHING

IN

S

W

IT

C

H

IN

G