Datasheet

3
UC1525B UC1527B
UC2525B UC2527B
UC3525B UC3527B
ELECTRICAL CHARACTERISTICS:
Unless otherwise stated, these specifications apply for T
A
= –55°C to +125°C for the
UC1525B and UC1527B; –40°C to +85°C for the UC2525B and UC2527B; 0°C to +70°C for the UC3525B and UC3527B; +VIN =
20V, T
A
=T
J
.
PARAMETER TEST CONDITIONS
UC1525B/UC2525B
UC1527B/UC2527B
UC3525B
UC3527B
MIN TYP MAX MIN TYP MAX UNITS
Oscillator Section (Note 3)
Initial Accuracy (Notes2&3) T
J
= 25°C ±2 ±6 ±2 ±6 %
Voltage Stability (Notes2&3) VIN=8Vto35V ±0.3 ±1 ±1 ±2 %
Temperature Stability (Note 2) Over Operating Range ±3 ±6 ±3 ±6 %
Minimum Frequency RT = 200kW,CT=0.1mF 120 120 Hz
Maximum Frequency RT = 2kW, CT = 470pF 400 400 kHz
Current Mirror I
RT
= 2mA 1.7 2.0 2.2 1.7 2.0 2.2 mA
Clock Amplitude (Notes2&3) 3.0 3.5 3.0 3.5 V
Clock Width (Notes2&3) T
J
= 25°C 0.3 0.5 1.0 0.3 0.5 1.0 ms
Sync Threshold 1.2 2.0 2.8 1.2 2.0 2.8 V
Sync Input Current Sync Voltage = 3.5V 1.0 2.5 1.0 2.5 mA
Error Amplifier Section (VCM = 5.1V)
Input Offset Voltage 0.5 5 2 10 mV
Input Bias Current 1 10 1 10 mA
Input Offset Current 1 1 mA
DC Open Loop Gain RL ³ 10 MegW 60 75 60 75 dB
Gain-Bandwidth Product (Note 2) A
V
= 0dB, T
J
= 25°C 1 2 1 2 MHz
Output Low Level 0.2 0.5 0.2 0.5 V
Output High Level 3.8 5.6 3.8 5.6 V
Common Mode Rejection V
CM
= 1.5V to 5.2V 60 75 60 75 dB
Supply Voltage Rejection VIN = 8V to 35V 50 60 50 60 dB
PWM Comparator
Minimum Duty Cycle 0 0 %
Maximum Duty Cycle (Note 3) 45 49 45 49 %
Input Threshold (Note 3) Zero Duty Cycle 0.7 0.9 0.7 0.9 V
Input Threshold (Note 3) Maximum Duty Cycle 3.3 3.6 3.3 3.6 V
Input Bias Current (Note 2) 0.05 1.0 0.05 1.0 mA
Shutdown Section
Soft Start Current V
SHUTDOWN
= 0V, V
SOFTSTART
=0V
25 50 80 25 50 80 mA
Soft Start Low Level V
SHUTDOWN
= 2.5V 0.4 0.7 0.4 0.7 V
Shutdown Threshold To outputs, V
SOFTSTART
=
5.1V, T
J
=25°C
0.6 0.8 1.0 0.6 0.8 1.0 V
Shutdown Input Current V
SHUTDOWN
= 2.5V 0.4 1.0 0.4 1.0 mA
Shutdown Delay (Note 2) V
SHUTDOWN
= 2.5V, T
J
= 25°C 0.2 0.5 0.2 0.5 ms
Output Drivers (Each Output) (Vc = 20V)
Output Low Level I
SINK
= 20mA 0.2 0.4 0.2 0.4 V
I
SINK
= 100mA 1.0 2.0 1.0 2.0 V
Output HIgh Level I
SOURCE
= 20mA 18 19 18 19 V
I
SOURCE
= 100mA 17 18 17 18 V
Undervoltage Lockout V
COMP
and V
SOFTSTART
=
High
678 678V
Collector Leakage VC = 35V 200 200 mA