We tried to connect OSC pin to GND, but the output freq is only running up to 6KHz.
In the E/C table, when OSC is connected to GND pin, the freq. should be in the range of the 15K - 27K, isn't? please help to check the schematic as attached file.
Regards
Brian
Hi Brian,
The output voltage frequency may not match the configured PWM frequency when in current regulation. As you can see in figure 3 in the datasheet, the duty cycle can vary from 8% to 100% depending if the VSENSE ≥ VREF. If VSENSE is always less than VREF during one PWM cycle, the duty cycle will be 100% which will make the output frequency appear to be lower frequency that the PWM frequency. This is expected behavior of this part.
Regards,
Pablo Armet
Thanks.
Here there are some problem we found with DRV110.
(Plot 1) It looks the voltage and current are NOT stable, and found audible noise after power on in 3min.
(Plot 2) after power on 3min, it looks the waveform is getting normally and the audible noise is improved.
Are above behavior normally? or what happened.
