SLUSE53 December 2024 BQ25751
PRODUCTION DATA
請參考 PDF 數據表獲取器件具體的封裝圖。
To set the maximum input current using the ILIM_HIZ pin, a pull-down resistor to PGND is used. When using a 2-mΩ RAC_SNS resistor, the input current limit is controlled by: IAC_MAX = KILIM / RILIM_HIZ.
The actual input current limit is the lower value between ILIM_HIZ pin setting and register setting (IAC_DPM). For example, if the register setting is 20 A, and ILIM_HIZ pin has a 5-k? resistor (KILIM = 50 A-k?) to ground for 10 A, the actual input current limit is 10 A. ILIM_HIZ pin can be used to set the input current limit when EN_ILIM_HIZ_PIN bit is set to 1. The device regulates the pin at VREF_ILIM_HIZ. If pin voltage exceeds VREF_ILIM_HIZ, the device enters input current regulation. Entering input current regulation through the pin sets the IAC_DPM_STAT and FLAG bits, and produces an interrupt to host. The interrupt can be masked via the IAC_DPM_MASK bit.
The ILIM_HIZ pin can also be used to monitor input current. When not in input current regulation, the voltage on ILIM_HIZ pin (VILIM_HIZ) is proportional to the input current. Pin voltage can be used to monitor input current with the following relationship: IAC = KILIM x VILIM_HIZ / (RILIM_HIZ x VREF_ILIM_HIZ).
If ILIM_HIZ pin is shorted, the input current limit is set by the IAC_DPM register. If hardware input current limit function is not needed, it is recommended to short this pin to GND. If ILIM_HIZ pin is pulled above VIH_ILIM_HIZ, the device enters HIZ mode (refer to Section 7.3.3.4). The ILIM_HIZ pin function can be disabled by setting the EN_ILIM_HIZ_PIN bit to 0. When the pin is disabled, input current limit and monitoring functions as well as HIZ mode control via the pin are not available.
KILIM is defined as 50 A×kΩ referenced to a 2-mΩ sense resistor. A larger sense resistor provides a larger sense voltage and higher regulation accuracy, but changes the gain from the ILIM_HIZ pin. For example, using a 5-mΩ resistor yields KILIM = 50 (A×kΩ) × 2 (mΩ) / 5 (mΩ) = 20 (A×kΩ).