SLVSI02 May 2025 DRV8376-Q1
PRODUCTION DATA
The ILIMIT pin on the DRV8376 device is used to set a cycle-by-cycle current limit proportional to the voltage on the ILIMIT pin (VLIM). The analog voltage VLIM can be set using a digital-to-analog converter from an external microcontroller or a resistor divider. Applying voltage equal to VVREF on the ILIMIT pin disables the cycle-by-cycle current limit, and applying (VVREF/ 2 - 0.25) V on ILIMIT pin sets the current limit at the maximum threshold of 4A.
The equations below shows how to set the ILIMIT pin voltage (VLIM) with respect to VVREF = 3.3V, current sense amplifier gain (GAIN) = 1V/A, to set cycle-by-cycle current limit to 2A (sum of all the low side FET current).
Use Equation 7 to calculate values for a GVDD sourced resistor divider with resistors RILIM1 and RILIM2 to set current limit equal to the 2A calculated current limit. Other voltage rails like AVDD or VREF voltage can also be used to derive the ILIMIT pin voltage. Use appropriate capacitive filter at ILIMIT pin if needed.
To reduce current load on GVDD, RILIM2 is configured to 10kΩ in this example.
Cycle-by-cycle limit can also occur with 100% PWM duty cycle inputs using an internal PWM pulse to monitor the current with ILIM. Setting the PWM_100_DUTY_SEL configures the frequency of the internal PWM pulse to 20kHz or 40kHz.