BQ24250C_15 Datasheet, PDF (22/46 Pages) Texas Instruments – bq24250C 2A Single Input I2C, Standalone Switch-Mode Li-Ion Battery Charger with Power-Path Management

bq24250C
SLUSBY7 – JULY 2014
www.ti.com
Figure 19. 2A Load Step Transient
8.4.6 Input Voltage Based DPM
During normal charging process, if the input power source is not able to support the programmed or default
charging current, the supply voltage deceases. Once the supply drops to VIN_DPM, the input current limit is
reduced down to prevent the further drop of the supply. When the IC enters this mode, the charge current is
lower than the set. This feature ensures IC compatibility with adapters with different current capabilities without a
hardware change.
8.4.7 Sleep Mode
The bq24250C enters the low-power sleep mode if the voltage on VIN falls below sleep-mode entry threshold,
VBAT+VSLP, and VIN is higher than the under-voltage lockout threshold, VUVLO. This feature prevents draining
the battery during the absence of VIN. When VIN < VBAT+VSLP, the bq24250C turns off the PWM converter,
turns on the battery FET, sends a single 256µs pulse is sent on the STAT and INT outputs and the FAULT/STAT
bits of the status registers are updated in the I²C. Once VIN > VBAT+VSLP with the hysteresis, the FAULT bits
are cleared and the device initiates a new charge cycle.
8.4.8 Input Over-Voltage Protection
The bq24250C provides over-voltage protection on the input that protects downstream circuitry. The built-in input
over-voltage protection to protect the device and other components against damage from overvoltage on the
input supply (Voltage from VIN to PGND). When VIN > VOVP, the bq24250C turns off the PWM converter, turns
the battery FET, sends a single 256μs pulse is sent on the STAT and INT outputs and the FAULT/STAT bits of
the status registers and the battery/supply status registers are updated in the I²C. Once the OVP fault is
removed, the FAULT bits are cleared and the device returns to normal operation. The OVP threshold for the
bq24250 is programmable from 6.5V to 10.5V using VOVP bits in register #7.
8.4.9 NTC Monitor
The bq24250C includes the integration of an NTC monitor pin that complies with a modified JEITA specification
(PSE also available upon request). The voltage based NTC monitor allows for the use of any NTC resistor with
the use of the circuit shown in Figure 20.
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