HA17384SPS Datasheet, PDF (10/29 Pages) Hitachi Semiconductor – High Speed Current Mode PWM Control IC for Switching Power Supply

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP
Timing Chart
Signal Name
Input voltage
V_IN Pin 7
UVL1
Internal signal which
cannot be externally
monitored.
Reference voltage
Vref Pin 8
Waveform timing (Outline)
Power ON
2V
0V
IC turn ON
OVP input
Power OFF
Stationary operation
OVP latched
condition
16 V
(8.4 V)
This voltage is determined
by the transformer
10 V
(7.6 V)
Reset of
OVP latch
7.0 V
2V
( ) shows the case
using HA17385H
0V
5V
0V
4.7 V
4.7 V
UVL2
Internal signal which
cannot be externally
0V
monitored.
2.8 V
Oscillation voltage of
triangular wave
R_T/C_T Pin 4
Start up signal
Internal signal which
cannot be externally
monitored.
0V
IC operates and
PWM output stops.
0V
PWM latch setting signal
internal signal which
0V
cannot be externally
monitored.
Error amplifier input signal _0V
V_FB Pin 2
1.2 V
Start up latch
release
V_COMP
7.0 V typ
(OVP input)
Error amplifier output signal
V_COMP Pin 1
0V
I_D *1
I_D
OVP latch signal
Internal signal which
0V
cannot be externally
monitored.
V_IN
PWM output voltage
0V
V_OUT Pin 6
Note: 1. I_D indicates the power MOSFET drain current; it is actually observed as voltage V_S generated
by power MOSFET current detection source resistance R_S.
V_COMP indicates the error amp output voltage waveform. Current mode operation is
performed so that a voltage 1/3 that of V_COMP is the current limiter level.
Rev.3.00 Jun 15, 2005 page 10 of 28