UDQ2543B Allegro MicroSystems, Inc., UDQ2543B Datasheet - Page 4

• Manufacturer Part Number: UDQ2543B
• Description: Protected Quad Power Driver
• Manufacturer: Allegro MicroSystems, Inc.

2543
PROTECTED
QUAD POWER DRIVER
CURRENT LIMIT (24 V SUPPLY)
CURRENT LIMIT (12 V SUPPLY)
SHORT CIRCUIT
TIME
NOT TO SCALE
NORMAL LOAD
Dwg. WP-013-1
UDx2559B/EB, with improved shortcircuit protection and thermal
limiting, are recommended.
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. For rapid current decay (fast turn-OFF
speeds), the use of Zener diodes will raise the flyback voltage and
improve performance. However, the peak voltage must not exceed the
specified minimum sustaining voltage (V
increase. As described above, the drive current to the affected
output stage is diverted, causing the output stage to go linear, limiting
the peak output current to approximately 1 A. As the power dissipation
of that output stage increases, a thermal gradient sensing circuit will
become operational, further decreasing the drive current to the af-
fected output stage and reducing the output current to a value depen-
dent on supply voltage (I
corrected, the output stage will return to its normal saturated condition.
a single channel should be shorted at a time. Multiple overload
conditions may be tolerated provided rated package power
dissipation is not exceeded.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
For incandescent lamp applications, the UDx2549B/EB or
Bifilar (unipolar) stepper motors, relays, or solenoids can be driven
In the event of a shorted load, the load current will attempt to
Due to the independent operation of the four channels, only
OUT
2.4/V
SUPPLY
SUPPLY
). If the fault condition is
+ V
Z
+ V
F
V
OUT(SUS)
).