Overview
The BQ24745RHDRG4 from Texas Instruments is a high-efficiency, SMBus-controlled multi-chemistry battery charger. This device is designed for space-constrained applications and supports charging of two, three, or four series Li+ cells, as well as other battery chemistries such as NiCd, NiMH, and Lead Acid. The BQ24745 features an integrated input-current comparator and offers dynamic power management (DPM) and input power limiting, ensuring efficient and safe battery charging.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| DCIN Input Voltage Range | 7 - 24 | V |
| Battery Voltage Range | Up to 19.2 | V |
| Charge Voltage Regulation Accuracy | ±0.5% | |
| Charge Current Regulation Accuracy | ±3% | |
| Adapter Current Regulation Accuracy | ±3% | |
| Input Current Sense Amp Accuracy | ±2% | |
| Switching Frequency | 300 kHz | |
| Efficiency | >95% | |
| Minimum Driver Dead-Time | 30 ns | |
| Maximum Effective Duty Cycle | 99.5% | |
| Package Type | 28-pin, 5-mm × 5-mm QFN |
Key Features
- NMOS-NMOS Synchronous Buck Converter with high efficiency (>95%) and 300-kHz frequency.
- High-accuracy voltage and current regulation with ±0.5% charge voltage accuracy and ±3% charge current accuracy.
- Dynamic Power Management (DPM) and input power limiting to prevent overloading the AC adapter.
- Integrated input-current comparator with adjustable threshold and hysteresis.
- Internal soft-start and charge enable pin.
- Charge Voltage DAC (1.024 V–19.2 V) and Charge Current DAC (128 mA–8.064 A).
- Adapter Current Limit DPM DAC (256 mA–11.008 A).
- Status and monitoring outputs including AC/DC adapter present with adjustable voltage threshold.
- Support for multiple battery chemistries: Li+, NiCd, NiMH, Lead Acid, etc.
- Low standby current: < 10-µA battery current with adapter removed and < 1-mA input DCIN current with adapter present and charge disabled.
Applications
- Notebook and ultra-mobile computers.
- Portable data-capture terminals.
- Portable printers.
- Medical diagnostics equipment.
- Battery bay chargers.
- Battery backup systems.
Q & A
- What is the primary function of the BQ24745RHDRG4?
The BQ24745RHDRG4 is a high-efficiency, SMBus-controlled multi-chemistry battery charger designed for charging two, three, or four series Li+ cells and other battery chemistries.
- What is the input voltage range for the BQ24745RHDRG4?
The input voltage range is 7 V to 24 V.
- What is the efficiency of the BQ24745RHDRG4?
The device has an efficiency of greater than 95%.
- What are the key features of the BQ24745RHDRG4's power management?
The device features dynamic power management (DPM), input power limiting, and an integrated input-current comparator.
- What types of battery chemistries does the BQ24745RHDRG4 support?
The device supports Li+, NiCd, NiMH, Lead Acid, and other battery chemistries.
- What is the package type of the BQ24745RHDRG4?
The device is available in a 28-pin, 5-mm × 5-mm QFN package.
- How accurate is the charge voltage regulation of the BQ24745RHDRG4?
The charge voltage regulation accuracy is ±0.5%.
- What is the switching frequency of the BQ24745RHDRG4?
The switching frequency is 300 kHz.
- Does the BQ24745RHDRG4 have any safety features?
Yes, it includes features like dynamic power management, input power limiting, and an integrated comparator to monitor input current.
- What are some typical applications for the BQ24745RHDRG4?
Typical applications include notebook and ultra-mobile computers, portable data-capture terminals, portable printers, medical diagnostics equipment, battery bay chargers, and battery backup systems.
- What is the standby current of the BQ24745RHDRG4 when the adapter is removed?
The standby current is less than 10-µA when the adapter is removed.
