SRP Hitachi Semiconductor, SRP Datasheet - Page 14

• Manufacturer Part Number: SRP
• Description: High Speed Current Mode PWM Control IC for Switching Power Supply
• Manufacturer: Hitachi Semiconductor

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP
14
1.0
0.8
0.6
0.4
0.2
0.0
Point:
0
CS terminal
1) At maximum rated load, the setting should be made to give
2) When the OVP latch is operated, the setting should be made
C
Figure 3 Operation Diagram of Current Sensing Part
Light load
Error Amplifier Output Voltage Vcomp (V)
approximately 90% of area A below.
in area B or C.
1
1.4V
V
CS
1 V
Figure 4 Current Sense Characteristics
V
Current sensing
level
Latch setting
pulse
2
CS
Heavy load
V
Error voltage
+
3
COMP
CS
A
R
2 R
4
4.4V
2V
R
S
5
A : Stationary operation / PWM
B : Current limit operation / Max duty cycle
C : No sensitivity area / No PWM output
F
latch
CS
(Current-mode operation)
Q
B
V
COMP terminal
(Error output)
6
Latch setting pulse
(Implemented in triagular
wave oscillator)
COMP
1
3
7
7.5V
PWM pulse
8