Datasheet
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DESCRIPTION (continued)
ABSOLUTE MAXIMUM RATINGS
(1)
RECOMMENDED OPERATING CONDITIONS
(1)
UC1525A, UC1527A
UC2525A, UC2527A
UC3525A, UC3527A
SLUS191C – FEBRUARY 1997 – REVISED JANUARY 2008
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
These functions are also controlled by an undervoltage lockout which keeps the outputs off and the soft-start
capacitor discharged for sub-normal input voltages. This lockout circuitry includes approximately 500 mV of
hysteresis for jitter- free operation. Another feature of these PWM circuits is a latch following the comparator.
Once a PWM pulse has been terminated for any reason, the outputs will remain off for the duration of the period.
The latch is reset with each clock pulse. The output stages are totem-pole designs capable of sourcing or sinking
in excess of 200 mA. The UC1525A output stage features NOR logic, giving a LOW output for an OFF state. The
UC1527A utilizes OR logic which results in a HIGH output level when OFF.
UCx52xA UNIT
+V
IN
Supply voltage 40
V
C
Collector supply voltage 40
V
Logic inputs – 0.3 to +5.5
Analog inputs – 0.3 to +V
IN
Output current, source or sink 500
Reference output current 50 mA
Oscillator charging current 5
Power dissipation at T
A
= +25 ° C
(2)
1000
mW
Power dissipation at T
C
= +25 ° C
(2)
2000
Operating junction temperature – 55 to 150
Storage temperature range – 65 to 150 ° C
Lead temperature (soldering, 10 seconds) 300
(1) Values beyond which damage may occur.
(2) See Thermal Characteristics table.
MIN MAX UNIT
+V
IN
Input voltage 8 35
V
V
C
Collector supply voltage 4.5 35
Sink/source load current (steady state) 0 100
Sink/source load current (peak) 0 400 mA
Reference load current 0 20
Oscillator frequency range 100 400 Hz
Oscillator timing resistor 2 150 k Ω
Oscillator timing capacitorm 0.001 0.01 µ F
Dead time resistor range 0 500 Ω
UC1525A, UC1527A – 55 125
Operating ambient temperature range UC2525A, UC2527A – 25 85 ° C
UC3525A, UC3527A 0 70
(1) Range over which the device is functional and parameter limits are assured.
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Product Folder Link(s): UC1525A, UC1527A UC2525A, UC2527A UC3525A, UC3527A