米6体育平台手机版

ZHCSOK3 august 2023 BQ25756

PRODUCTION DATA

封装选项

机械数据 (封装 | 引脚)

RRV|36
- MPQF623A

散热焊盘机械数据 (封装 | 引脚)

RRV|36
- QFND780

订购信息

zhcsok3_oa

8.3.4.1.1 Charge Current Programming (ICHG pin and ICHG_REG)

There are two distinct thresholds to limit the charge current (if both are enabled, the lowest limit of these will apply):

ICHG pin pull down resistor (hardware control)
ICHG_REG register bits (host software control)

To set the maximum charge current using the ICHG pin, a pull-down resistor to PGND is used. It is required to use a 5-mΩ R_{BAT_SNS} sense resistor. The charge current limit is controlled by:

Equation 4.

I_{C H G_M A X} = \frac{K_{I C H G}}{R_{I C H G}}

The precharge current limit is defined as I_{PRECHG_MAX} = 20% x I_{CHG_MAX}, and the termination current is I_TERM = 10% x I_{CHG_MAX}.

The actual charge current limit is the lower value between ICHG pin setting and I²C register setting (ICHG_REG). For example, if the register setting is 10 A (0xC8), and ICHG pin has a 10-kΩ resistor (K_ICHG = 50 A-kΩ) to ground for 5 A, the actual charge current limit is 5 A. The device regulates ICHG pin at V_{REF_ICHG}. If ICHG pin voltage exceeds V_{REF_ICHG}, the device enters charge current regulation.

The ICHG pin can also be used to monitor charge current when device is not in charge current regulation. When not in charge current regulation, the voltage on ICHG pin (V_ICHG) is proportional to the actual charging current. ICHG pin can be used to monitor battery current with the following relationship:

Equation 5.

I_{B A T} = \frac{{K_{I C H G} \times V}_{I C H G}}{R_{I C H G} \times V_{R E F_I C H G}}

For example, if ICHG pin is set with 10-kΩ resistor, and the ICHG voltage 1.0V, the actual charge current is between 2.4 A to 2.6 A (based on K_ICHG specified).

If ICHG pin is shorted to PGND, the charge current limit is set by the ICHG_REG register. If hardware charge current limit function is not needed, it is recommended to short this pin to PGND. The ICHG pin function can be disabled by setting the EN_ICHG_PIN bit to 0 (recommended when pin is shorted to PGND). When the pin is disabled, charge current limit and monitoring functions via ICHG pin are not available.

To set the maximum charge current using the ICHG_REG register bits, write to the ICHG_REG register bits. The charge current limit range is from 400 mA to 20,000 mA with 50 mA/step. The default ICHG_REG is set to maximum code, allowing ICHG pin to limit the current in hardware.