3
UC1524A
UC2524A
UC3524A
PARAMETER TEST CONDITIONS
UC1524A / UC2524A UC3524A UNITS
MIN TYP MAX MIN TYP MAX
Oscillator Section (Unless otherwise specified, R
T = 2700
Ω
, CT = 0.01 mfd)
Initial Accuracy T
J = 25°C 414345394347kHz
Over Operating Range 40.2 45.9 38.2 47.9 kHz
Temperature Stability* Over Operating Temperature Range 1 2 1 2 %
Minimum Frequency R
T = 150k
Ω
, CT = 0.1mfd 140 120 Hz
Maximum Frequency R
T = 2.0k
Ω
, CT = 470pF 500 500 kHz
Output Amplitude* 3 3.5 3 3.5 V
Output Pulse Width* 0.29 0.5 1.0 0.3 0.5 1.0
µ
s
Ramp Peak 3.3 3.5 3.7 3.3 3.5 3.7 V
Ramp Valley T
J = 25°C 0.7 0.8 0.9 0.7 0.8 0.9 V
Ramp Valley T.C. -1.0 -1.0 mV/°C
Error Amplifier Section (Unless otherwise specified, V
CM = 2.5V)
Input Offset Voltage 0.5 5 2 10 mV
Input Bias Current 1 5 1 10
µ
A
Input Offset Current .05 1 0.5 1
µ
A
Common Mode Rejection Ratio V
CM = 1.5 to 5.5V 70 80 70 80 dB
Power Supply Rejection Ratio V
IN = 10 to 40V 70 80 70 80 dB
Output Swing (Note 1) 5.0 0.5 5.0 0.5 V
Open Loop Voltage Gain
∆
V
O= 1 to 4V, RL
≥
10M
Ω
72 80 64 80 dB
Gain-Bandwidth* T
J = 25°C, AV = 0dB 1 3 1 3 MHz
DC Transconductance*§ T
J = 25°C, 30k
Ω≤
RL
≤
1M
Ω
1.7 2.3 1.7 2.3 mS
P.W.M. Comparator (R
T = 2k
Ω
, CT = 0.01mfd)
Minimum Duty Cycle V
COMP = 0.5V 0 0 %
Maximum Duty Cycle V
COMP = 3.8V 45 45 %
Current Limit Amplifier (Unless otherwise specified, Pin 5 = 0V)
Input Offset Voltage T
J = 25°C, E/A Set for Maximum
Output
190 200 210 180 200 220 mV
Over Operating Temperature Range 180 220 170 230 mV
Input Bias Current -1 -10 -1 -10
µ
A
Common Mode Rejection Ratio V
(pin 5) = -0.3V to + 5.5V 50 60 50 60 dB
Power Supply Rejection Ratio V
IN = 10 to 40V 50 60 50 60 dB
Output Swing (Note 1) Minimum Total Range 5.0 0.5 5.0 0.5 V
Open-Loop Voltage Gain
∆
V
O = 1 to 4V, RL
≥
10M
Ω
70 80 70 80 dB
Delay Time* Pin 4 to Pin 9,
∆
V
IN = 300mV 300 300 ns
Output Section (Each Output)
Collector Emitter Voltage I
C = 100
µ
A 6080 6080 V
Collector Leakage Current V
CE = 50V .1 20 .1 20
µ
A
ELECTRICAL CHARACTERISTICS:
Unless otherwise stated, these specifications apply for TA = -55°C to +125°C for the
UC1524A, -40° to +85°C for the UC2524A, and 0°C to + 70°C for the UC3524A; V
IN
= VC = 20V, TA =TJ.
* These parameters are ensured by design but not 100% tested in production.
§ DC transconductance (g
M
) relates to DC open-loop voltage gain according to the following equation: A
V
=g
M
R
L
where R
L
is the resistance from pin 9 to the common mode voltage.
The minimum g
M
specification is used to calculate minimum A
V
when the error amplifier output is loaded.
Note 1: Min Limit applies to output high level, max limit applies to output low level.
