Overview
The BQ25970YFFT is a high-efficiency battery charging solution developed by Texas Instruments. This device utilizes a patent-pending switched capacitor charger architecture optimized for a 50% duty cycle, which significantly reduces power loss across the charging cable and limits temperature rise in the application. It is designed for fast charging applications, particularly in smartphones and other portable devices, offering a 97% efficient power stage capable of delivering up to 8A of charging current.
The BQ25970YFFT supports various battery types, including Li-Ion, Li-Polymer, Lead Acid, and NiMH, and features a Constant Voltage/Constant Current Control Loop. It also includes robust diagnostic and protection features to ensure safe and reliable charging operations.
Key Specifications
| Specification | Details |
|---|---|
| Efficiency | 97% efficient power stage |
| Charging Current | Up to 8A |
| Input Voltage | 2x battery voltage (3.5 V to 4.65 V) |
| Output Current | 2x of input current (up to 4.5 A) |
| Package | DSBGA (56 pins), 3.00 mm x 3.20 mm |
| Operating Temperature | -40°C to 85°C |
| ADC Resolution | 12-bit effective analog-to-digital converter |
| Accuracy | ±0.5% BUS voltage, ±0.5% VOUT voltage, -0.4% to 0.2% BAT voltage with differential sensing |
| Current Accuracy | ±1.5% BAT current at 6 A with external RSENSE |
| Temperature Accuracy | ±1% BAT temperature, ±1% BUS temperature, ±4°C Die temperature |
Key Features
- Switched capacitor architecture optimized for 50% duty cycle, reducing power loss and temperature rise.
- Integrated programmable protection features including input over-voltage protection (BUS_OVP), input over-current protection (BUS_OCP), battery over-voltage protection (BAT_OVP), and output over-voltage protection (VOUT_OVP).
- Support for external OVP FET (VAC_OVP up to 17 V).
- Battery and connector temperature monitoring.
- Integrated 12-bit effective analog-to-digital converter (ADC) for precise voltage and current measurements.
- Programmable settings for system optimization, including VBATREG and IBATREG regulation for system load and wall adapter transients.
- STAT, FLAG, and MASK options for interrupts.
- Dual-phase architecture reducing input cap requirements and output voltage ripple.
- Constant Voltage/Constant Current Control Loop and programmable recharge threshold.
- Robust diagnostic features such as Charge Safety Timer, Overvoltage Protection, Undervoltage Protection, Short-Circuit Protection, and Temperature Protection.
Applications
- Smartphones
- Tablet PCs
- Portable electronic devices requiring fast and efficient battery charging.
- Systems needing simultaneous charging of multiple batteries in parallel.
Q & A
- What is the maximum charging current of the BQ25970YFFT?
The BQ25970YFFT can deliver up to 8A of charging current.
- What is the efficiency of the BQ25970YFFT's power stage?
The power stage of the BQ25970YFFT is 97% efficient.
- What types of batteries does the BQ25970YFFT support?
The BQ25970YFFT supports Li-Ion, Li-Polymer, Lead Acid, and NiMH batteries.
- What protection features are integrated into the BQ25970YFFT?
The device includes input over-voltage protection (BUS_OVP), input over-current protection (BUS_OCP), battery over-voltage protection (BAT_OVP), output over-voltage protection (VOUT_OVP), and temperature monitoring.
- How does the BQ25970YFFT reduce power loss during charging?
The device reduces power loss by using a switched capacitor architecture optimized for a 50% duty cycle, which halves the cable current and reduces temperature rise.
- What is the operating temperature range of the BQ25970YFFT?
The operating temperature range is -40°C to 85°C.
- Does the BQ25970YFFT support external OVP FET?
Yes, the BQ25970YFFT supports external OVP FET (VAC_OVP up to 17 V).
- What is the resolution of the integrated ADC in the BQ25970YFFT?
The integrated ADC has a 12-bit effective resolution.
- Can the BQ25970YFFT charge multiple batteries in parallel?
Yes, the device can charge two batteries in parallel, enabling a boosting effect for faster charging.
- What diagnostic features are available in the BQ25970YFFT?
The device includes diagnostic features such as Charge Safety Timer, Overvoltage Protection, Undervoltage Protection, Short-Circuit Protection, and Temperature Protection.
