AP3302

Document number:DS38882 Rev. 4 - 2

10 of 17

www.diodes.com

March 2017

© Diodes Incorporated

AP3302

Figure 2

Active Frequency Dithering

To improve the EMI performance, the AP3302 integrates an active frequency dithering function. A consecutive frequency-dithering signal is

injected to the SENSE pin after LEB time. As shown in figure 3, the frequency-dithering signal is repeating over and over again with a period of

500

excursion to improve the EMI performance.

SENSE

4

LEB

From FB

0

500

s

+Vs_jitter

-Vs_jitter

Jitter

PWM

Comparator

Figure 3

Current Mode PWM Control

The AP3302 operates as a current mode controller; the output switch is turned on by every oscillator cycle and turned off when the primary peak

current reaches the threshold level established by the FB pin. The primary current signal is converted to a voltage signal on current sense

S

FB

PK

R

V

I

3

/

)

0

.

1

(





120kHz

22kHz