The bq2423x series of devices are highly integrated Li-ion linear chargers and system power-path management devices targeted at space-limited portable applications. The devices operate from either a USB port or ac adapter and support charge currents between 25 mA and 500 mA. The high-input-voltage range with input overvoltage protection supports low-cost, unregulated adapters. The USB input current limit accuracy and start-up sequence allow the bq2423x to meet USB-IF inrush current specification. Additionally, the input dynamic power management (VIN-DPM) prevents the charger from crashing poorly designed or incorrectly configured USB sources.
The bq2423x features dynamic power-path management (DPPM) that powers the system while simultaneously and independently charging the battery. The DPPM circuit reduces the charge current when the input current limit causes the system output to fall to the DPPM threshold, thus supplying the system load at all times while monitoring the charge current separately. This feature reduces the number of charge and discharge cycles on the battery, allows for proper charge termination, and enables the system to run with a defective or absent battery pack. Additionally, this enables instant system turn-on even with a totally discharged battery. The power-path management architecture also permits the battery to supplement the system current requirements when the adapter cannot deliver the peak system currents, enabling the use of a smaller adapter.
The battery is charged in three phases: conditioning, constant current, and constant voltage. In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if the internal temperature threshold is exceeded.
The charger power stage and charge current sense functions are fully integrated. The charger function has high-accuracy current and voltage regulation loops, charge status display, and charge termination. The input current limit and charge current are programmable using external resistors.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
bq24230 | VQFN (16) | 3.00 mm × 3.00 mm |
bq24232 |
Changes from I Revision (November 2015) to J Revision
Changes from H Revision (June 2015) to I Revision
Changes from G Revision (March 2015) to H Revision
Changes from F Revision (November 2014) to G Revision
Changes from E Revision (January 2014) to F Revision
Changes from D Revision (December 2013) to E Revision
Changes from C Revision (July 2010) to D Revision
Changes from B Revision (March 2009) to C Revision
Changes from A Revision (December 2008) to B Revision
Changes from * Revision (October 2008) to A Revision
PART NUMBER(1) | VOVP | VOUT(REG) | VDPM | OPTIONAL FUNCTION | MARKING |
---|---|---|---|---|---|
bq24230 | 6.6 V | 4.4 V | VO(REG) – 100 mV | TD | CGN |
bq24232 | 10.5 V | 4.4 V | VO(REG) – 100 mV | ITERM | NXK |
PIN | I/O | DESCRIPTION | ||
---|---|---|---|---|
NAME | NUMBER | |||
bq24230 | bq24232 | |||
TS | 1 | 1 | I | External NTC Thermistor Input. Connect the TS input to the NTC thermistor in the battery pack. TS monitors a 10-kΩ NTC thermistor. For applications that do not utilize the TS function, connect a 10-kΩ fixed resistor from TS to VSS to maintain a valid voltage level on TS. |
BAT | 2,3 | 2, 3 | I/O | Charger Power Stage Output and Battery Voltage Sense Input. Connect BAT to the positive terminal of the battery. Bypass BAT to VSS with a 4.7-μF to 47-μF ceramic capacitor. |
CE | 4 | 4 | I | Charge Enable Active-Low Input. Connect CE to a high logic level to disable battery charging. OUT is active and battery supplement mode is still available. Connect CE to a low logic level to enable the battery charger. CE is internally pulled down with ~285 kΩ. Do not leave CE unconnected to ensure proper operation. |
EN2 | 5 | 5 | I | Input Current Limit Configuration Inputs. Use EN1 and EN2 control the maximum input current and enable USB compliance. See Table 1 for the description of the operation states. EN1 and EN2 are internally pulled down with ~285 kΩ. Do not leave EN1 or EN2 unconnected to ensure proper operation. |
EN1 | 6 | 6 | I | |
PGOOD | 7 | 7 | O | Open-drain Power Good Status Indication Output. PGOOD pulls to VSS when a valid input source is detected. PGOOD is high-impedance when the input power is not within specified limits. Connect PGOOD to the desired logic voltage rail using a 1-kΩ – 100-kΩ resistor, or use with an LED for visual indication. |
VSS | 8 | 8 | – | Ground. Connect to the thermal pad and to the ground rail of the circuit. |
CHG | 9 | 9 | O | Open-Drain Charging Status Indication Output. CHG pulls to VSS when the battery is charging. CHG is high impedance when charging is complete and when charger is disabled. |
OUT | 10,11 | 10, 11 | O | System Supply Output. OUT provides a regulated output when the input is below the OVP threshold and above the regulation voltage. When the input is out of the operation range, OUT is connected to VBAT. Connect OUT to the system load. Bypass OUT to VSS with a 4.7-μF to 47-μF ceramic capacitor. |
ILIM | 12 | 12 | I | Adjustable Current Limit Programming Input. Connect a 3.1-kΩ to 7.8-kΩ resistor from ILIM to VSS to program the maximum input current (EN2=1, EN1=0). The input current includes the system load and the battery charge current. Leaving ILIM unconnected disables all charging. In USB100/500 mode (EN2 = 0, EN1= 0/1), ILIM can be left floating. |
IN | 13 | 13 | I | Input Power Connection. Connect IN to the connected to external DC supply (AC adapter or USB port). The input operating range is 4.35 V to 6.6 V. The input can accept voltages up to 26 V without damage but operation is suspended. Connect bypass capacitor 1 μF to 10 μF to VSS. |
TMR | 14 | 14 | I | Timer Programming Input. TMR controls the precharge and fast-charge safety timers. Connect TMR to VSS to disable all safety timers. Connect a 18-kΩ to 72-kΩ resistor between TMR and VSS to program the timers a desired length. Leave TMR unconnected to set the timers to the 5-hour fast charge and 30-minute precharge default timer values. |
TD | 15 | - | I | Termination Dsable Input. Connect TD high to disable charger termination. Connect TD to VSS to enable charger termination. TD is checked during start-up only and cannot be changed during operation. See the TD section in this data sheet for a description of the behavior when termination is disabled. TD is internally pulled down to VSS with ~285 kΩ. Do not leave TD unconnected to ensure proper operation. |
ITERM | - | 15 | I | Termination Current Programming Input. Connect a 0-Ω to 15-kΩ resistor from ITERM to VSS to program the termination current. Leave ITERM unconnected to set the termination current to the internal default 10% threshold. |
ISET | 16 | 16 | I/O | Fast-Charge Current Programming Input. Connect a 1.8-kΩ to 36-kΩ resistor from ISET to VSS to program the fast-charge current level. Charging is disabled if ISET is left unconnected. While charging, the voltage at ISET reflects the actual charging current and can be used to monitor charge current. See the Charge Current Translator section for more details. |
Thermal Pad | – | An internal electrical connection exists between the exposed thermal pad and the VSS pin of the device. The thermal pad must be connected to the same potential as the VSS pin on the printed-circuit board. Do not use the thermal pad as the primary ground input for the device. The VSS pin must be connected to ground at all times. |
EN2 | EN1 | Maximum Input Current Into IN Pin |
---|---|---|
0 | 0 | 100 mA. USB100 mode |
0 | 1 | 500 mA. USB500 mode |
1 | 0 | Set by an external resistor from ILIM to VSS |
1 | 1 | Standby (USB suspend mode) |