The following is a Flyback SMPS.
Is R7 a good place for a loop injection resistor for the purpose of feedback loop measurement?
(Flyback = CCM, continous, 97khz, 22.5w, vout=30v, Vin = 230VAC)
The whole error amplifier network has been designed with two extra opamps (U2 & U3) “encasing” a loop injection resistor (R7), which is to be used for loop test signal injection, for establishing the gain and phase margins of this SMPS.
A frequency analyser (eg AP300) would be used for the loop injection, via a coupling transformer, as follows
http://www.ridleyengineering.com/loop-stability-requirements.html?showall=&limitstart=
Attached is the schematic in pdf and jpeg, as well as the LTspice simulation.
Is R7 a good place for a loop injection resistor for the purpose of feedback loop measurement?
(Flyback = CCM, continous, 97khz, 22.5w, vout=30v, Vin = 230VAC)
The whole error amplifier network has been designed with two extra opamps (U2 & U3) “encasing” a loop injection resistor (R7), which is to be used for loop test signal injection, for establishing the gain and phase margins of this SMPS.
A frequency analyser (eg AP300) would be used for the loop injection, via a coupling transformer, as follows
http://www.ridleyengineering.com/loop-stability-requirements.html?showall=&limitstart=
Attached is the schematic in pdf and jpeg, as well as the LTspice simulation.
