Hi,
I have build the BLDC Motor controller circuit using UC2625. The circuit is same as given in the page 1 of the UC2625 data sheet except for:
1. used MOSFET IRFI9540G in place of IRF9350,
2. used MOSFET IRFI540N in place of IRF532,
3. 87 Ohm resistors in place of 10 Ohm resistors for MOSFET gate inputs.
I have used 12V Zener Diode, SB560 Schottky Diode, Diode 6A10 between P-channel and N channel MOSFET and VMOTOR=24Volts (current limited to 2Amps).
When I connect the Hall sensor cables only (not motor winding cables), the voltages of PUA, PUB, PUC, PDA, PDB and PDC are correct and change as Hall sensor signals change. But when I connect the motor winding cables, my motor (Maxon make EC 45 )does not run and all the higher side pins PUA, PUB and PUC measure 23.4 volts and low side pins PDA, PDB, PDC measure 0 Volts. SSTART (pin 24) measures 0.2Volts which was earlier 4.5 volts, RC Brake (pin 21) measure 3.3volts. I have 51K ohm resistor from SSTART (pom 24) to VREF (pin 2). VREF measure 4.6 Volts. The same thing is seen when I disconnect the motor winding cables and short the phase windings (winding 1 and winding 2) to measure current.
I have checked the circuit and it is fine.
What is the problem? Could anyone please help me urgently.
Thanks
