AP63356Q/AP63357Q

Document number: DS41948 Rev. 1 - 2

21 of 28

www.diodes.com

September 2020

© Diodes Incorporated

AP63356Q/AP63357Q

15

External Loop Compensation Design (continued)

The loop gain at the crossover frequency has unity gain. Therefore, the compensator resistance, R5, is determined by:

�������� =

����

����

Eq. 15

Where:









Be aware that most ceramic capacitors will degrade with voltage stress or temperature extremes. Refer to its datasheet and use its worst case

capacitance value for calculations.

The compensation capacitors C5 and C6 are then equal to:

�������� =

���������������� ∙ ����������������

���������������� ∙ ��������

Eq. 16

�������� = ������������ (

��������

,

����

)

Eq. 17

Where:



IOUT is the output load current

The inclusion of C6 can increase gain margin and can decrease phase margin. In most cases, C6 is optional and may be omitted.

The zero,

�������� = [

����

,

����

]

Eq. 18