HA16178P Datasheet, PDF (14/25 Pages) Renesas Technology Corp – Power Factor Correction Controller IC

HA16178P/FP
2. Operating Frequency
The HA16178 operating frequency fosc is determined by adjusting the timing resistor Rt (the RT pin, pin 9) and the
timing capacitance Ct (the CT pin, pin 10). The operating frequency is approximated by the following expression:
fosc
=
1.755 × 10⁶
Rt ^(kΩ) × Ct ^(pF)
(kHz)
When the IC is operated at high frequencies, the expression becomes less accurate due to IC internal delay time, etc.
Please confirm operation the value with the actually mounted IC. The maximum operating frequency is 400 kHz. As a
reference, the operating frequency data when the timing resistor and the timing capacitance are changed is shown in the
below figure.
1000
Timing capacitance
100
Ct
470 pF
1000 pF
2200 pF
10
4700 pF
1
1
10
100
Timing Resistance (kΩ)
Figure 2 Operating Frequency Characteristics
REJ03D0903-0100 Rev.1.00 Jun 12, 2007
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