kalaianand
Advanced Member level 4
hello friends
my non-isolated buck converter specification:
Input: 28V-158V.
Load current: 6A
output voltage: 24V
switching device: IRFP460 (500V, 20A)
PWM control IC: ST 3524
Switching frequency: 30kHz
By referring datasheet i made some modification such that ST3524 operates at 98% duty cycle(shorting collectors and emitters and output side). and i used TLP 250 IC for isolated gate signal.
in ST 3524, Pin2( non-inverter) is set to 2.5V. Pin1(inverting) is feedback voltage directly from the output, using voltage divider circuit. When it start regulating the output voltage pulse width start reducing but creating lots of noise. inductor creating sound, pulse is distorting much. when i try to increase the load noise become much. voltage level at comensation pin is distorting much at switching frequency. high frequency noises are coming.
please guide me on closed loop technique. i used linear voltage divider circuit to pin1, is this right? or any other compensation technique i need to follow?
thank u
my non-isolated buck converter specification:
Input: 28V-158V.
Load current: 6A
output voltage: 24V
switching device: IRFP460 (500V, 20A)
PWM control IC: ST 3524
Switching frequency: 30kHz
By referring datasheet i made some modification such that ST3524 operates at 98% duty cycle(shorting collectors and emitters and output side). and i used TLP 250 IC for isolated gate signal.
in ST 3524, Pin2( non-inverter) is set to 2.5V. Pin1(inverting) is feedback voltage directly from the output, using voltage divider circuit. When it start regulating the output voltage pulse width start reducing but creating lots of noise. inductor creating sound, pulse is distorting much. when i try to increase the load noise become much. voltage level at comensation pin is distorting much at switching frequency. high frequency noises are coming.
please guide me on closed loop technique. i used linear voltage divider circuit to pin1, is this right? or any other compensation technique i need to follow?
thank u