CS3524A Datasheet, PDF (4/6 Pages) Cherry Semiconductor Corporation – Voltage Mode PWM Control Circuit with 200mA Output Drivers

Typical Performance Characteristics continued
Quiescent Supply Current vs. Supply Voltage Over
Temperature
10
Shutdown Delay From PWM Comparator
9
8
T_A = -55°C
7
T_A = 25°C
6
T_A = 125°C
5
4
3
2
Note: Outputs off. R_T = ∞
1
0
0
10
20
30
40
50
SUPPLY VOLTAGE V_IN (V)
20
OUTPUT at
15
V_OA or V_OB
10
5
V_IN = 20V
R_L = 2kΩ
0
T_A = 25˚C
5
4
3
INPUT at V_OB
2
1
0
Note: Minimum input pulse width
to latch is 200ns
0
1
2
3
DELAY TIME (µs)
Oscillator Frequency vs. Timing Components Resistor
Over Timing Capacitance
1M
V_IN = 20V
T_A = 25˚C
100k
10k
1k
C_{T = 1.0nf}
C_{T = 3.0nf}
C_{T = 10nf}
C_{T = 30nf}
C_{T = 100nf}
100
1
f≈
1.15
R_TC_T
2
5
10 20
50 100
TIMING RESISTOR - R_T (kΩ)
Output Dead Time vs. Timing Capacitor Value
10
5.0
V_IN = 20V
R_T = 2700Ω
T_A = 25˚C
2.0
1.0
0.5
0.2
0.1
1
Note: Dead time = osc output pulse
width plus output delay
2
5
10 20
50 100
TIMING CAPACITOR - C_T (nf)
Current Limit Amplifier Delay
OUTPUT at COMP
6
5
Overdrive
4
5%
10%
3
20%
2
50%
1
0
INPUT at I_SENSE+
0.2
0.1
V_IN 20V T_A 25˚C
EA+ = V_REF
I_SENSE– = Gnd
0.0
0
1
2
3
4
DELAY TIME (µs)
Turn-Off Delay From Shutdown
20
15
V_IN = 20V
R_L = 2kΩ
10
T_A = 25˚C
5
OUTPUT at
V_OA OR V_OB
0
1.0
0.5
INPUT at
SHUTDOWN
0.0
Note: Minimum input pulse width
to latch is 200ns
0
1
2
3
DELAY TIME (µs)
4