I'm having an odd problem with the DRV8313. The design has two separate motor channels. The breadboard uses two DRV8313EVM boards modified to interface with an external microcontroller. It works fine. However, the first run of PCBs short the 24V motor supply briefly on power up. The PCBs use the DRV8313RHH (markings: DRV8313 TI 5AI CQ10 G4), rather than the DRV8313PWP. An LT4363-1 (current limit 5A) ramps the motor supply voltage in about 3ms. The PCBs glitch the supply (draw excessive current for about 0.5ms) as the voltage ramps between 1-3V. Sometimes the LT4363-1 current limit trips, sometimes not. Heating up the PCB tends to reduce the short current or interval. With the motor supply voltage at 24V, the DRV8313s on the PCB function normally. The states of the reset and sleep inputs don't affect the glitch. To eliminate other possible sources for the glitch, I wired up a DRV8313RHH with minimal connections. (inputs and OUT pins floating) The hand-wired DRV8313RHH glitched the supply like the PCB. Any ideas about what could be causing the glitch?
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