Providing improved output current limiting, the UDK, UDN, and
UDQ2559B, EB, and LB quad power drivers combine AND logic
gates and high-current bipolar outputs with complete output protection.
16
Each of the four outputs will sink 700 mA in the on state. The outputs
have a minimum breakdown voltage (load dump) of 60 V and a
sustaining voltage of 40 V. The inputs are compatible with TTL and
5 V CMOS logic systems.
OUT
OUT
GROUND
GROUND
OUT
OUT
1
4
2
K
3
3
4
5
6
2
7
K
8
1
16
IN
15
IN
14
ENABLE
13
GROUND
12
GROUND
V
11
CC
10
IN
IN
9
Dwg. PP-017-1
4
3
2
1
ABSOLUTE MAXIMUM RATINGS
at TA = 25°C
Output Voltage, V
Over-Current Protected Output Voltage,
V
. . . . . . . . . . . . . . . . . . . 25 V
OUT
Output Current, I
Supply Voltage, VCC .. . . . . . . . . 7.0 V
Input Voltage, VIN or V
Package Power Dissipation,
PD . . . . . . . . . . . . . . . . See Graph
Operating Temperature Range, T
Prefix ‘UDK’ . . . . -40°C to +125°C
Prefix ‘UDN’ . . . . . -20°C to +85°C
Prefix ‘UDQ’ . . . . . -40°C to +85°C
Storage Temperature Range,
TS . . . . . . . . . . . . -55°C to +150°C
*Outputs are peak current limited at
approximately 1.0 A per driver. See
Circuit Description and Application for
further information.
. . . . . . . . . 60 V
OUT
. . . . . . . . . 1.0 A*
OUT
. . . . . . 7.0 V
EN
A
Over-current protection for each channel has been designed into
these devices and is activated at approximately 1 A. It protects each
output from short circuits with supply voltages up to 25 V. When an
output current trip point is reached, that output stage is driven linearly
resulting in a reduced output current level. If an over-current or shortcircuit condition continues, the thermal-limiting circuits will first sense
the rise in junction temperature and then the rise in chip temperature,
further decreasing the output current. Under worst-case conditions,
these devices will tolerate short circuits on all outputs, simultaneously.
These devices can be used to drive various loads including incandescent lamps (without warming or limiting resistors) or inductive
loads such as relays, solenoids, or dc stepping motors.
The suffix ‘B’ devices are 16-pin power DIPs, the suffix ‘EB’
devices are 28-lead power PLCCs and suffix ‘LB’ devices are 16-lead
power SOICs for surface-mount applications. All three packages are
of batwing construction to provide for maximum package power
dissipation.
FEATURES
■ 700 mA Output Current per Channel
■ Independent Over-Current Protection for Each Driver
■ Thermal Protection for Device and Each Driver
■ Low Output-Saturation Voltage
■ Integral Output Flyback Diodes
■ TTL and 5 V CMOS Compatible Inputs
■ Pin-Compatible With UDQ2543B/EB and UDK2549B/EB
Always order by complete part number: a prefix to
indicate operating temperature range + the basic four-digit
part number + a suffix to indicate package style, e.g., UDK2559LB .
Typical Data 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.
* All inputs simultaneously, all other tests are performed with each input tested separately.
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TYPICAL OUTPUT
CHARACTERISTIC
THERMAL
GRADIENT
SENSING
NOT TO SCALE
OUT
OUT
T = 165°C
J
JUNCTION
OUTPUT VOLTAGE, V
TEMP. LIMIT
T < 150°C
J
V
OUT(SAT)
OUTPUT CURRENT, I
TYPICAL OUTPUT BEHAVIOR
NORMAL LAMP IN-RUSH CURRENT
I
TRIP
Dwg. GP-013
CIRCUIT DESCRIPTION AND APPLICATION
INCANDESCENT LAMP DRIVER
High incandescent lamp turn-ON/in-rush currents can contribute to
poor lamp reliability and destroy semiconductor lamp drivers. Warming or current-limiting resistors protect both driver and lamp but use
significant power either when the lamp is OFF or when the lamp is
ON, respectively. Lamps with steady-state current ratings up to 700
mA can be driven by these devices without the need for warming
(parallel) or current-limiting (series) resistors.
When an incandescent lamp is initially turned ON, the cold filament is at minimum resistance and would normally allow a 10x to 12x
in-rush current. With these drivers, during turn-ON, the high in-rush
current is sensed by the internal low-value sense resistor. Drive current
to the output stage is then diverted by the shunting transistor, and the
load current is momentarily limited to approximately 1.0 A. During
this short transition period, the output current is reduced to a value
dependent on supply voltage and filament resistance. During lamp
warmup, the filament resistance increases to its maximum value, the
output stage goes into saturation and applies maximum rated voltage to
the lamp.
INDUCTIVE LOAD DRIVER
Bifilar (unipolar) stepper motors, relays, or solenoids can be driven
directly. The internal flyback diodes prevent damage to the output transistors
by suppressing the high-voltage spikes that occur when turning OFF an
inductive load.
LAMP CURRENT
0
For rapid current decay (fast turn-OFF speeds), the use of Zener diodes
NOT TO SCALE
will raise the flyback voltage and inprove performance. However, the peak
voltage must not exceed the specified minimum sustaining voltage (V
VZ + VF ≤ V
OUT(SUS)
).
SUPPLY
+
FAULT CONDITIONS
In the event of a shorted load, the load current will attempt to
increase. As described above, the drive current to the affected output
stage is reduced, causing the output stage to go linear, limiting the peak
output current to approximately 1 A. As the power dissipation of that
THERMAL GRADIENT SENSING
I
TRIP
CURRENT LIMIT
output stage increases, a thermal gradient sensing circuit will become
operational, further decreasing the drive current to the affected output
stage and reducing the output current to a value dependent on supply
voltage and load resistance.
Continuous or multiple overload conditions causing the chip
TIM
Dwg. WP-008
temperature to reach approximately 165°C will result in an additional
reduction in output current to maintain a safe level.
If the fault condition is corrected, the output stage will return to its
normal saturated condition.
NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.
2. Lead spacing tolerance is non-cumulative
3. Webbed lead frame. Leads 4, 5, 12, and 13 are internally one piece.
www.allegromicro.com
10.65
10.00
0° TO 8°
1.27
0.40
Dwg. MA-008-17A mm
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The products described here are manufactured under one or more
U.S. patents or U.S. patents pending.
Allegro MicroSystems, Inc. reserves the right to make, from time to
time, such departures from the detail specifications as may be
required to permit improvements in the performance, reliability, or
manufacturability of its products. Before placing an order, the user is
cautioned to verify that the information being relied upon is current.
Allegro products are not authorized for use as critical components
in life-support devices or systems without express written approval.
The information included herein is believed to be accurate and
reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringement of patents or other rights of
third parties which may result from its use.