PCA9420 datasheet(19/87 Pages) NXP

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NXP Semiconductors

PCA9420

Power management IC for low-power microcontroller applications

8.12.1 Battery charging management

Battery charging management supports typical constant current/constant voltage

charging profile for single cell Li-Ion battery, as well as pre-qualification (dead battery, low

battery), top-off mode, etc.; JEITA and thermal regulation compliant.

In PCA9420, there is an initial stage in the charger operation which sources ICHG_DEAD

current into VBAT and compares the voltage to 1.9 V level.

• If the voltage is higher than this threshold, the charger immediately proceeds to the

next state (pre-charge/ICHG_LOW current).

• Otherwise, there is a timer running for 5...40s (I2C programmable) called

ICHG_DEAD_TIMER, bits [7:6] in register 0x14 chg_ctl4. If the timer expires, the

battery doesn’t accept charge and is detected as a short.

ICHG_DEAD_CURRENT is sourced by the charger and is I2C programmable.

The dead charge fault timer can assert an interrupt (bit [6]

(ICHG_DEAD_TIMER_INT_MASK) from Sub_INT1_Mask register 05h), and the

software can make the final decision. If left masked, the charger always proceeds to the

next stage. This is the default PCA9420 operation. If the interrupt was enabled and has

triggered, the charger is disabled.

PCA9420

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 4.0 — 28 November 2022

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