SLUSFB0 August 2024 BQ25758S
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
There are two distinct thresholds to limit the output current regulation point (if both are enabled, the lowest limit of these will apply):
To set the maximum output current using the IOUT pin, a pull-down resistor to PGND is used. It is required to use a 5-mΩ ROUT_SNS sense resistor. The output current limit is controlled by:
The actual output current limit is the lower value between IOUT pin setting and I2C register setting (IOUT_REG). For example, if the register setting is 10A (0xC8), and ICHG pin has a 10-kΩ resistor (KICHG = 50 A-kΩ) to ground for 5A, the actual output current limit is 5A. The device regulates IOUT pin at 2V. If ICHG pin voltage exceeds 2V, the device enters output current regulation (CC mode).
The IOUT pin can also be used to monitor output current when device is not in output current regulation. The voltage on IOUT pin (VIOUT) is proportional to the actual output current. IOUT pin can be used to monitor output current with the following relationship:
For example, if IOUT pin is set with 10-kΩ resistor, and the IOUT voltage 1.0V, the actual output current is between 2.4A to 2.6A (based on KIOUT specified).
If IOUT pin is shorted to PGND, the current limit is set by the IOUT_REG register. If hardware output current limit function is not needed, it is recommended to short this pin to PGND. The IOUT pin function can be disabled by setting the EN_IOUT_PIN bit to 0 (recommended when pin is shorted to PGND). When the pin is disabled, output current limit and monitoring functions via IOUT pin are not available.
To set the maximum output current using the IOUT_REG register bits, write to the IOUT_REG register bits. The current limit range is from 400mA to 20,000mA with 50mA/step. The default IOUT_REG is set to maximum code, allowing IOUT pin to limit the current in hardware.