HA16158P Datasheet, PDF (15/23 Pages) Renesas Technology Corp – PFC & PWM Control IC

HA16158P/FP
5. Power Saving in Standby State (for PWM Control)
When the output load is light, as in the standby state, the operating frequency of the PWM control section is
automatically decreased in order to reduce switching loss.
Standby detection is performed by monitoring the PWM-COMP voltage, and the operating frequency is
decreased to a maximum of 1/64 of the reference frequency determined by an external timing resistance.
As standby detection is performed on a reference frequency pulse-by-pulse basis, the frequency varies
gently according to the output load.
RT _{9 Oscillator}
R
Q
S
PWM
Logic
driver
2 ^PWM-OUT
VREF
15 ^PWM-COMP
16 ^PWM-CS
f/64
Divider
reset
1.7V
Power Saving
Power Saving Peripheral Circuit
PWM-COMP
PWM-OUT
f
1.7V
f/64
Figure 5
Rev.0, Aug. 2002, page 15 of 23