SLVSDF3F MARCH 2017 – JANUARY 2019 TPSM846C23
The TPSM846C23 device senses the average output current using an internal sense FET. A sense FET conducts a scaled-down version of the power-stage current. Sampling this current in the middle of the low-side drive signal determines the average output current. This architecture achieves excellent current monitoring and better overcurrent threshold accuracy than the current sensing of a DC-resistance (DCR) inductor with minimal temperature variation and no dependence on power loss in a higher DCR inductor. Use the IOUT_CAL_OFFSET command to improve current sensing and overcurrent accuracy by removing systematic errors related to board layout after assembly. The device continually digitizes the sensed output current, and averages it to reduce measurement noise. The device then places the current value in the read-only register, READ_IOUT, which enables output-current telemetry.
This device cannot report negative (sinking) current. Any negative current is reported as zero amps.