1 Features

• Fully Compliant USB Charger
  • Selectable 100-mA and 500-mA Maximum Input Current
  • 100-mA Maximum Current Limit Ensures Compliance to USB-IF Standard
  • Input-based Dynamic Power Management (V_IN- DPM) for Protection Against Poor USB Sources
• 28-V Input Rating With Overvoltage Protection
• Integrated Dynamic Power-Path Management (DPPM) Function Simultaneously and Independently Powers the System and Charges the Battery
• Supports up to 500-mA Charge Current With Current Monitoring Output (ISET)
• Programmable Input Current Limit up to 500 mA for Wall Adapters
• Programmable Termination Current (bq24232)
• Programmable Precharge and Fast-Charge Safety Timers
• Reverse Current, Short-Circuit, and Thermal Protection
• NTC Thermistor Input
• Proprietary Start-Up Sequence Limits Inrush Current
• Status Indication – Charging/Done, Power Good
• Small 3 mm × 3 mm 16-Lead QFN Package

2 Applications

• Bluetooth™ Devices
• Low-Power Handheld Devices

3 Description

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 (V_IN-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.

1. For all available packages, see the orderable addendum at the end of the datasheet.

Typical Application Circuit

4 Revision History

Changes from I Revision (November 2015) to J Revision

• Changed from "Table 2" to "Table 1" in the Pin Functions Description column for pins EN2/EN1Go

Changes from H Revision (June 2015) to I Revision

• Changed the Pin Functions ISET pin description resistor value from 3-kΩ to 1.8-kΩ, to match the value in the Recommended Operating Conditions table. Go
• Changed K_TMR MIN TYP MAX values FROM "30, 40, 50" TO "36, 48, 60" s/kΩ, respectively, in the Timing Requirements tableGo
• Changed textual content of Input Voltage Dynamic Power Management, (VIN_DPM) section for clarification.Go
• Changed textual content of Dynamic Power Path Management (DPPM) section for clarification. Go
• Changed textual content of Battery Supplement Mode section for clarificationGo
• Changed textual content of Battery Pack Temperature Monitoring section for clarification.Go
• Added Modifying / Extending the Allowable Temperature Range for Charging sub-section heading and text for clarification.Go
• Changed "6.25-hour" TO " 7.5-hour" Fast Charge Safety Timer in the Using The bq24232 In A Stand-Alone Charger Application section.Go

Changes from G Revision (March 2015) to H Revision

• Changed CE pin Description in the Pin Functions table from "Connect CE to a high logic level to place the battery charger in standby mode...." to "Connect CE to a high logic level to disable battery charging".Go
• Changed the ILIM pin Description From: "Connect a 2.75-kΩ to 8.4-kΩ resistor...." To: "Connect a 3.1-kΩ to 7.8-kΩ resistor..."Go
• Changed "I_PRECHG Precharge current" spec to "K_IPRECHG Precharge current factor" in the Electrical Characteristics table.Go
• Moved timing specifications from Electrical Characteristics table to Timing Requirements table Go
• Changed Requirements for OUT Output section text from "> VBATUVLO" to "around 2.2 V". Go

Changes from F Revision (November 2014) to G Revision

• Added text to ILIM pin description for clarification.Go
• Moved T_stg spec to Absolute Maximum Ratings table and changed Handling Ragtings table title to ESD Ratings Go
• Deleted text string from second paragraph of Power On description for clarification Go

Changes from E Revision (January 2014) to F Revision

• Added Device Information and Handling Rating tables, Feature Description section, Device Functional Modes, Programming section, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section Go
• Changed V_RCH spec MIN, TYP, MAX terminology from V_O(REG) to V_BAT(REG) Go
• Added "Reset the timers by toggling CE pin." in the Dynamic Charge timers (TMR) Input description.Go

Changes from D Revision (December 2013) to E Revision

• Added T_J= 85°C to conditions statement for I_BAT(PDWN) specification.Go

Changes from C Revision (July 2010) to D Revision

• Changed the ILIM pin Description From: "Connect a 3.1-kΩ to 7.8-kΩ resistor..." To: "Connect a 2.75-kΩ to 8.4-kΩ resistor..."Go
• Changed POWER PATH I_IN max Test Condition From: R_ILIM = 3.1 kΩ to 7.8 kΩ To: R_ILIM = 2.75 kΩ to 8.4 kΩGo
• Changed UNITS from "ms" to "V" for V_LOWV specification in Electrical Characteristics table.Go
• Changed text following Equation 1 From: The valid resistor range is 3.2 kΩ to 8 kΩ To: The valid resistor range is 2.75 kΩ to 8.4 kΩGo
• Changed the Program the Input Current Limit (ILIM) section: K_ILIM = 1470 AΩ To: K_ILIM = 1530 AΩGo
• Changed the Program the Input Current Limit (ILIM) section: R_ISET = 1470 AΩ / 0.5 A = 2.94 kΩ To: R_ISET = 1530 AΩ / 0.5 A = 3.06 kΩGo
• Changed Program the Input Current Limit (ILIM) text From: Select the closest standard value, which for this case is 2.94 kΩ To: Select the closest standard value, which for this case is 3.06 kΩGo

Changes from B Revision (March 2009) to C Revision

• Changed globally RT1 and RT2 to Rs and RpGo
• Added Equation 2 and Equation 3, term explanations and resistance table.Go

Changes from A Revision (December 2008) to B Revision

• Changed Absolute Maximum Ratings I_O, OUT From: 600 mA To: 1700 mAGo
• Changed Absolute Maximum Ratings I_O, BAT (Discharge mode) From: 600 mA To: 1700 mAGo
• Changed Recommended Operating Conditions I_BAT From 500 MA To: 1500 mAGo
• Changed Recommended Operating Conditions I_CHG From 500 MA To: 1500 mAGo
• Added POWER PATH K_ILIM Test Conditions: I_LIM = 200 mA to 500 mAGo
• Changed the POWER PATH K_ILIM Values From: MIN =1320 TYP = 1470 MAX = 1620 To: MIN = 1380 TYP = 1530 MAX =1680Go
• Changed BATTERY CHARGER V_BAT(REG) MAX value From: 4.24 To: 4.23Go

Changes from * Revision (October 2008) to A Revision

• Changed the second paragraph of the DESCRIPTIONGo