ZHCSJR3B February 2019 – November 2019 BQ25887
PRODUCTION DATA.
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
PG | 1 | DO | Open drain active low power good indicator – Connect to the pull up rail via 10-kΩ resistor. LOW indicates a good input source if the input voltage is within VVBUS_OP, and can provide more than IPOORSRC (30mA). |
STAT | 2 | DO | Open drain charge status indicator – Connect to the pull-up rail via 10-kΩ resistor. LOW indicates charge in progress. HIGH indicates charge complete or charge disabled. When any fault occurs, the STAT pin blinks at 1Hz. The STAT function can be disabled when the STAT_DIS bit is set. |
CD | 3 | DI | Active High Chip Disable Pin – Pull CD high to disable charge and place the device in HIZ mode. ADC operation and I2C is still allowed when CD is high. Converter is enabled when CD pin is LOW and EN_CHG bit is 1. CD pin is internally pulled low with 900-kΩ resistor. |
SDA | 4 | DIO | I2C Interface Data – Connect SDA to the pull up rail through a 10-kΩ resistor. |
SCL | 5 | DI | I2C Interface Clock – Connect SCL to the pull up rail through a 10-kΩ resistor. |
INT | 6 | DO | Open drain active Interrupt Output – Connect INT to the pull up rail via a 10-kΩ resistor. The INT pin sends active low, 256-µs pulse to the host to report charger device status and fault. |
TS | 7 | AI | Temperature Qualification Voltage – Connect a negative temperature coefficient thermistor. Program temperature window with a resistor divider from REGN to TS to GND. Charge suspends when TS pin is out of range. Recommend 103AT-2 thermistor. |
ILIM | 8 | AI | Input Current Limit (IINDPM) – ILIM pin sets the maximum input current and can be used to monitor input current. IINDPM loop regulates ILIM pin voltage at 0.8V. When ILIM pin is less than 0.8V, the input current can be calculated by IIN = KILIM x VILIM / (RILIM x 0.8V). A resistor connected from ILIM pin to ground sets the input current limit as maximum (IINMAX = KILIM / RILIM). When ILIM pin is short to GND, the input current limit is set to maximum by ILIM. The actual input current limit is the lower limit set by ILIM pin (when EN_ILIM bit is HIGH) or IINDPM register bits. Input current limit less than 500mA is not supported on ILIM pin. The ILIM pin function can be disabled when EN_ILIM bit is 0. If ILIM pin is not used, pull this pin to GND.Do not float this pin.
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MID | 9 | AI | Voltage Input for Mid Point Between Cells in 2S1P Configuration – Connect MID to the negative terminal of the top cell and the positive terminal of the bottom cell. This pin measures the voltage of the bottom cell for cell balancing and VMID ADC measurement. For protection of bottom cell reverse plug in, connect a 300 ohm resistor in series between MID pin and mid connection point of the two battery cell. |
CBSET | 10 | P | Power pin for Cell Balancing – Connect CBSET to the mid point between the two batteries in 2S configuration with a current limit resistor. The resistor value determines the cell balancing current as calculated in Cell Balancing Section. The resistor chosen should not exceed 400 mA for cell balancing. |
REGN | 11 | P | Gate Drive Supply – Bias supply for internal MOSFETs driver and IC. Bypass REGN to GND with a 4.7-µF ceramic capacitor. REGN current limit is 50 mA. |
BTST | 12 | P | PWM High-side Driver Supply – Internally, BTST is connected to the cathode of the boot-strap diode. Connect a 47nF bootstrap capacitor from SW to BTST. |
BAT | 13, 14 | P | Battery Power Connection – Connect minimum recommended 10-µF capacitance after derating closely to the BAT pin and GND. |
SNS | 15, 16 | AO | Sense Output – Charge current sense pin. Place a 44-µF ceramic capacitor on this pin for stability of this output. |
SW | 17, 18 | P | Inductor Connection – Connect to the switched side of the external inductor. |
GND | 19, 20 | – | Ground Return |
PMID | 21, 22 | P | Blocking MOSFET Connection – The minimum recommended total input low-ESR capacitance on VBUS and PMID, after applied derating, is 10 uF. At least 1-uF is recommended at VBUS with the remainder at PMID. Typical value for PMID is 10 uF. |
VBUS | 23 | P | Input Supply – VBUS is connected to the external DC supply. Bypass VBUS to GND with at least 1-µF ceramic capacitor, placed as close to the IC as possible. |
PSEL | 24 | DI | Power Source Selection – HIGH indicates USB host source (500mA) and LOW indicates adapter source (3.0A). |