BQ24745
SMBus up to 4 cell level 2 Buck battery chager to support Multiple battery chemistries
BQ24745
- NMOS-NMOS Synchronous Buck Converter with
300-kHz Frequency and >95% Efficiency - 30-ns Minimum Driver Dead-Time and
99.5% Maximum Effective Duty Cycle - High-Accuracy Voltage and Current Regulation
- ±0.5% Charge Voltage Accuracy
- ±3% Charge Current Accuracy
- ±3% Adapter Current Accuracy
- ±2% Input Current Sense Amp Accuracy
- Integration
- Input Current Comparator, With Adjustable
Threshold and Hysteresis - Internal Soft-Start
- Input Current Comparator, With Adjustable
- Safety
- Dynamic Power Management (DPM)
- Up to 19.2-V Battery Voltage
- 7-V–24-V AC/DC-Adapter Operating Range
- Simplified SMBus Control Interface
- Charge 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 Outputs
- AC/DC Adapter Present With
Adjustable Voltage Threshold - Input Current Comparator With Adjustable
Threshold and Hysteresis - Current Sense Amplifier for Current Drawn
From Input Source
- AC/DC Adapter Present With
- Charge 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 Adapter
Present and Charge Disabled - 28-Pin, 5-mm × 5-mm QFN Package
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 mm QFN 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.
Technical documentation
Type | Title | Date | ||
---|---|---|---|---|
* | Data sheet | SMBus-Controlled Multi-chemistry Battery Charger With Input Current datasheet (Rev. D) | 05 Oct 2011 | |
Application note | How to Review a Multicell Switching Charger Schematic | 21 Sep 2011 | ||
More literature | Журнал по применению аналоговых компонентов 1 кв. 2010 | 23 Sep 2010 | ||
Analog Design Journal | Li-ion battery-charger solutions for JEITA compliance | 29 Jan 2010 |
Design & development
For additional terms or required resources, click any title below to view the detail page where available.
PMP9668 — Universal uP Controlled Battery Charger 24Vin 10 Aout max, 5/12V 2A & 5V 4A, 2 USB Ports Ref Design
Package | Pins | Download |
---|---|---|
VQFN (RHD) | 28 | View options |
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