米6体育平台手机版

ZHCSR87 December 2022 DRV8316C

PRODUCTION DATA

封装选项

机械数据 (封装 | 引脚)

RGF|40
- MPQF173F

散热焊盘机械数据 (封装 | 引脚)

RGF|40
- QFND672

订购信息

zhcsr87_oa

9.2.2.2.2 ILIM Implementation

The ILIM pin on the DRV8316C device is used to set a cycle-by-cycle current limit proportional to the voltage on the ILIM pin. The analog voltage ILIM can be set using a digital-to-analog converter from an external microcontroller or a resistor divider. Applying AVDD/2 on the ILIM pin disables the cycle-by-cycle current limit, and applying (AVDD/2 - 0.4) V on ILIM pin sets the current limit at the maximum threshold of 8-A.

Equation 13, Equation 14, and Equation 15 shows how to set the ILIM voltage with respect to AVDD = 3.3V to set cycle-by-cycle current limit to 2-A.

Equation 13.

1.55 V = 3.3 (\frac{10 k Ω}{R_{I L I M 1} + 10 k Ω})

Equation 14.

I L I M [V] = \frac{(1.25 - \frac{3.3}{2}) [V]}{8 A} \times 2 A + 1.65 V

Equation 15.

I L I M [V] = 1.55 V

Use Equation 16 to calculate values for an AVDD-sourced resistor divider with resistors RILIM1 and RILIM2 to set ILIM equal to the 2-A calculated current limit.

Equation 16.

I L I M [V] = A V D D (\frac{R_{I L I M 2}}{R_{I L I M 1} + R_{I L I M 2}})

To reduce current load on AVDD, R_ILIM2 is configured to be 10 kΩ as shown in Equation 17 and Equation 18.

Equation 17.

1.55 V = 3.3 (\frac{10 k Ω}{R_{I L I M 1} + 10 k Ω})

Equation 18.

R_{I L I M 1} = 11.29 k Ω

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.