Overview
The Texas Instruments BQ24745RHDTG4 is a high-efficiency, synchronous battery charger integrated circuit designed for multi-chemistry battery charging applications. It features an SMBus-controlled interface, dynamic power management (DPM), and input power limiting, making it ideal for space-constrained designs. The IC supports charging of two, three, or four series Li+ cells and is packaged in a 28-pin, 5-mm x 5-mm VQFN package.
Key Specifications
| Parameter | Value |
|---|---|
| Absolute Vin (Safety Rating) Max | 30 V |
| Battery Charge Voltage Max | 24 V |
| Cell Chemistry | Li-Ion/Li-Polymer, NiCd, NiMH, Lead Acid |
| Charge Current Max | 10 A (programmable up to 8.064 A) |
| Control Interface | SMBus |
| Control Topology | Switch-Mode Buck |
| Number of Series Cells | 2, 3, 4 |
| Operating Vin Min/Max | 7 V / 24 V |
| Package Type | 28-VQFN (5x5 mm) |
| Operating Temperature | -40°C to 125°C (TJ) |
| Special Features | Power Path, Dynamic Power Management (DPM), Input Power Limiting |
Key Features
- 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
- 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
- Charge Enable Pin
- < 10-uA Battery Current with Adapter Removed, < 1-mA Input DCIN Current with Adapter Present and Charge Disabled
Applications
- Laptop and Ultra-Mobile Computers
- Portable Data-Capture Terminals
- Portable Printers
- Medical Diagnostics Equipment
- Battery Bay Chargers
- Battery Backup Systems
Q & A
- What is the BQ24745RHDTG4 used for?
The BQ24745RHDTG4 is used as a high-efficiency, synchronous battery charger for multi-chemistry battery applications.
- What types of battery chemistries does the BQ24745RHDTG4 support?
The BQ24745RHDTG4 supports Li-Ion, Li-Polymer, NiCd, NiMH, and Lead Acid battery chemistries.
- What is the maximum charge current of the BQ24745RHDTG4?
The maximum charge current is 10 A, but it is programmable up to 8.064 A.
- What is the operating voltage range of the BQ24745RHDTG4?
The operating voltage range is from 7 V to 24 V.
- What interface does the BQ24745RHDTG4 use for control?
The BQ24745RHDTG4 uses an SMBus interface for control.
- What are the key features of the BQ24745RHDTG4's power management?
The key features include dynamic power management (DPM), input power limiting, and high-accuracy voltage and current regulation.
- What is the package type and size of the BQ24745RHDTG4?
The package type is 28-VQFN, and the size is 5 mm x 5 mm.
- What are some common applications of the BQ24745RHDTG4?
Common applications include laptop and ultra-mobile computers, portable data-capture terminals, portable printers, medical diagnostics equipment, battery bay chargers, and battery backup systems.
- How does the BQ24745RHDTG4 manage input current?
The BQ24745RHDTG4 manages input current through an integrated current-sense amplifier and an input-current comparator with adjustable threshold and hysteresis.
- What is the efficiency of the BQ24745RHDTG4's synchronous buck converter?
The efficiency of the synchronous buck converter is greater than 95%.
