Other Parts Discussed in Thread: UCC3895
hi all
for a project i use ucc3895 as a smps controller but , i dont have any pulse on output ports. \
i jast use EVB circuit but it not working .DSA0030412.pdf
Q9 and R3 both are there and at emiter Q9 iahve a ramp . but after R3 that ramp is so small smaler than .5 V at pick .
i think that pin 3 (.. ramp pin .. ) . is pulled down to grand with a 100R or smaller resistor . at datasheet block diagram ramp pin have a mosfet to ground . must be pull down sink pin ????