HA16107P Datasheet, PDF (28/40 Pages) Hitachi Semiconductor – PWM Switching Regulator for High-performance Voltage Mode Control

HA16107P/FP, HA16108P/FP
Operating waveform at the TL pin
When overcurrent is input at the point
where the duty cycle is 0%.
7
6
5
B
4
3
A
2
Test circuit
HA16107
V_IN = 18V
V_IN
R_T1 = R_T2 = 27 kΩ
C_T = 470 pF
f_OSC = 100 kHz
TL
C_L
1000 pF
Clock
OUT
CL(+)
27 kΩ
470 pF ^RT1
C_T S_T
R_T2 Vref
27 kΩ
+
1 µF ^SW
C_ST
+ ^{1 µF}
1
Triangle
wave
0
CL(+) when
input at a
duty of 0%
t_ON
t_OFF
0.5 sec/div
CL(+) when
input at a
Output pulse shutdown region
duty of 30%
t1
SW ON SW OFF
t2
When overcurrent is input at the point
where the duty cycle is 30%.
7
Du = ^t1 × 100 (%)
t2
Enlargement of section ^A
6
ab
c
5
V_TL
4
B
3
2
A
1
0
CTL discharged at 4 µA
CTL discharged at 12 µA
t
Enlargement of section ^B
V_TL
CTL discharged at 4 µA
t_ON
SW ON SW OFF
t_OFF
0.5 sec/div
Output pulse shutdown region
t
a to b : PWM pulse output is High
b
: The point where overcurrent
is detected
b _to c : PWM pulse output is Low.
Rev.4.00 Jun 15, 2005 page 28 of 39