BQ24745 Series

SMBus up to 4 cell level 2 Buck battery chager to support Multiple battery chemistries

Catalog

SMBus up to 4 cell level 2 Buck battery chager to support Multiple battery chemistries

Part	Number of Cells [Min]	Number of Cells [Max]	Supplier Device Package	Mounting Type	Current - Charging	Battery Pack Voltage	Voltage - Supply (Max) [Max]	Charge Current - Max [Max]	Operating Temperature [Min]	Operating Temperature [Max]	Package / Case	Interface	Battery Chemistry	Type	Function	Supplied Contents
Texas Instruments BQ24745RHDT	2 cells	4	28-VQFN (5x5)	Surface Mount	Constant - Programmable	19.2 V	24 V	8.064 A	-40 °C	125 ¯C	28-VFQFN Exposed Pad	I2C	Multi-Chemistry
Texas Instruments BQ24745RHDR	2 cells	4	28-VQFN (5x5)	Surface Mount	Constant - Programmable	19.2 V	24 V	8.064 A	-40 °C	125 ¯C	28-VFQFN Exposed Pad	I2C	Multi-Chemistry
Texas Instruments BQ24745EVM														Power Management	Battery Charger	Board(s)

Catalog

SMBus up to 4 cell level 2 Buck battery chager to support Multiple battery chemistries

Key Features

• NMOS-NMOS Synchronous Buck Converter with300-kHz Frequency and >95% Efficiency30-ns Minimum Driver Dead-Time and99.5% Maximum Effective Duty CycleHigh-Accuracy Voltage and Current Regulation±0.5% Charge Voltage Accuracy±3% Charge Current Accuracy±3% Adapter Current Accuracy±2% Input Current Sense Amp AccuracyIntegrationInput Current Comparator, With AdjustableThreshold and HysteresisInternal Soft-StartSafetyDynamic Power Management (DPM)Up to 19.2-V Battery Voltage7-V–24-V AC/DC-Adapter Operating RangeSimplified SMBus Control InterfaceCharge Voltage DAC (1.024 V–19.2 V)Charge Current DAC (128 mA–8.064 A)Adapter Current Limit DPM DAC(256 mA–11.008 A)Status and Monitoring OutputsAC/DC Adapter Present WithAdjustable Voltage ThresholdInput Current Comparator With AdjustableThreshold and HysteresisCurrent Sense Amplifier for Current DrawnFrom Input SourceCharge Any Battery Chemistry: Li+, NiCd,NiMH, Lead Acid, Etc.Charge Enable Pin< 10-µA Battery Current With Adapter Removed< 1-mA Input DCIN Current With AdapterPresent and Charge Disabled28-Pin, 5-mm × 5-mm QFN PackageNMOS-NMOS Synchronous Buck Converter with300-kHz Frequency and >95% Efficiency30-ns Minimum Driver Dead-Time and99.5% Maximum Effective Duty CycleHigh-Accuracy Voltage and Current Regulation±0.5% Charge Voltage Accuracy±3% Charge Current Accuracy±3% Adapter Current Accuracy±2% Input Current Sense Amp AccuracyIntegrationInput Current Comparator, With AdjustableThreshold and HysteresisInternal Soft-StartSafetyDynamic Power Management (DPM)Up to 19.2-V Battery Voltage7-V–24-V AC/DC-Adapter Operating RangeSimplified SMBus Control InterfaceCharge Voltage DAC (1.024 V–19.2 V)Charge Current DAC (128 mA–8.064 A)Adapter Current Limit DPM DAC(256 mA–11.008 A)Status and Monitoring OutputsAC/DC Adapter Present WithAdjustable Voltage ThresholdInput Current Comparator With AdjustableThreshold and HysteresisCurrent Sense Amplifier for Current DrawnFrom Input SourceCharge Any Battery Chemistry: Li+, NiCd,NiMH, Lead Acid, Etc.Charge Enable Pin< 10-µA Battery Current With Adapter Removed< 1-mA Input DCIN Current With AdapterPresent and Charge Disabled28-Pin, 5-mm × 5-mm QFN Package

Description

The bq24745 is a high-efficiency, synchronous battery charger with an integrated input-current comparator, offering low component count for space-constrained, multi-chemistry battery-charging applications. The input-current, charge-current, and charge-voltage DACs allow very high regulation accuracies that can be easily programmed by the system power-management microcontroller using the SMBus interface. The bq24745 charges two, three, or four series Li+ cells, and is available in a 28-pin, 5-mm × 5 mmQFN package. The bq24745 features dynamic power management (DPM) and input power limiting. These features reduce battery-charge current when the input power limit is reached to avoid overloading the ac adaptor when supplying the load and the battery charger simultaneously. A highly accurate current-sense amplifier enables precise measurement of input current from the ac adapter, allowing monitoring the overall system power. If the adapter current is above the programmed low-power threshold, a signal is sent to host so that the system optimizes its performance to the power available from the adapter. An integrated comparator monitors the input current through the current-sense amplifier, and indicates when the input current exceeds a programmable threshold limit. The bq24745 is a high-efficiency, synchronous battery charger with an integrated input-current comparator, offering low component count for space-constrained, multi-chemistry battery-charging applications. The input-current, charge-current, and charge-voltage DACs allow very high regulation accuracies that can be easily programmed by the system power-management microcontroller using the SMBus interface. The bq24745 charges two, three, or four series Li+ cells, and is available in a 28-pin, 5-mm × 5 mmQFN package. The bq24745 features dynamic power management (DPM) and input power limiting. These features reduce battery-charge current when the input power limit is reached to avoid overloading the ac adaptor when supplying the load and the battery charger simultaneously. A highly accurate current-sense amplifier enables precise measurement of input current from the ac adapter, allowing monitoring the overall system power. If the adapter current is above the programmed low-power threshold, a signal is sent to host so that the system optimizes its performance to the power available from the adapter. An integrated comparator monitors the input current through the current-sense amplifier, and indicates when the input current exceeds a programmable threshold limit.