There is whistle occured in our PCBA and we changed the value of output cpacitor POS and NEG as below.
Case1:
Co(POS),Co(NEG):DNI
The whistle is disappeared, but occured strong ripple wave.
case2:
Co(POS),Co(NEG):1uF
The whistle is improved with acceptable level and the strong ripple wave in case1 is disappeared.
case3:Co(POS),Co(NEG):2.2uF or 4.7uF or 10uF
With above value the whistle occured.
So my question is that is it possible to use 1uF capacitors for Co(POS) and Co(NEG)?
In datasheet the recommanded value is from 4.7uF to 20uF.
By the way this IC is used for 5.5 LCD power circuit.
Thanks!