5 Current Sensing
The DRV821x/8220EVM comes with current sensing circuitry consisting of a low-side sense resistor and a
current sensing amplifier. The current sensing capabilities can only be used with the DSG/PDSG devices.
show the schematic for the current sensing circuity. The components enclosed by the red rectangles are the
current sensing components. The sense resistor (R20) is connected between the GND pin of the device to the
larger GND plane of the EVM. R20 is populated with a 0Ω resistor on the EVM but can be replaced with another
resistor value if the user desires to use it for current sensing. C11 is used for filtering noise at the GND pin of the
device and is not populated on the EVM.
The user needs to populate C11 with a desired value. The current sense amplifier and the surrounding
components (R17, R18, and C6) are not populated on the EVM. The user needs to populate the amplifier and
the surrounding components to use the current sensing capabilities. The current sense amplifier is the
TLV9051IDRL which can be ordered
. R17 and R18 set the closed loop gain of the amplifier and have to be
chosen by the user.
The output of the current sense amplifier (AMP_OUT) can be measured at the “ISENSE” pin on header J4.
AMP_OUT is connected to an ADC pin on the MCU to monitor the current and to create current sensing
algorithms.
Figure 5-1. Current Sensing Schematic
Current Sensing
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DRV821xEVM and DRV8220EVM User's Guide
SLOU540A – NOVEMBER 2020 – REVISED DECEMBER 2020
Copyright © 2020 Texas Instruments Incorporated