Hello experts,
I am currently using the driver DRV8353FH to power an H-bridge circuit, thus, only drivers A and B are being used. I am currently having an issue with the current amplifiers.
- I have placed shunt resistors as stated in datasheet in legs A and B (between SPX and SNX).
- I have connected leg C as follows: SHC, SPC, SNC, SOC are grounded; GHC and GLC are not connected.
- There are no differences between my schematic design and the suggestion from the datasheet, except for capacitor between VREF and GND is 1uF instead of 0.1uF as datasheet suggests.
- I have the GAIN pin set as High-Z (currently floating) which should yield a 20V/V gain. With this configuration, the driver pin GAIN is internally set to 3.1 V when driver is ENABLED.
- VREF is set to 3.3V which I measure correctly in the PCB.
With the afordmentioned configuration and no current flowing through the shunts and driver enabled, I expect SOA and SOB to be Vref/2 (3.3V/2 = 1.65V). Nevertheless, I am reading 0 V at SOA and SOB.
It does not seem that the driver is damaged since the same issue is occuring on independent PCBs.
Do you have any suggestions on why this issue is occuring? I would appreciate any comment or insight about a possible solution. Also, don't hesitate to ask if you need any extra information about the matter.
Thank you in advance and best regards!
