Overview
The bq25070DQCR, produced by Texas Instruments, is a highly integrated LiFePO4 linear battery charger designed for space-limited portable applications. This IC operates from either a USB port or an AC adapter and is capable of charging a single-cell LiFePO4 battery with up to 1A of charge current. It features a 30V input voltage range with input over-voltage protections, supporting low-cost unregulated adapters. The bq25070DQCR incorporates a unique charging algorithm for LiFePO4 cells, eliminating the constant voltage mode control typically used in Li-Ion battery charge cycles, which significantly reduces charge time.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Voltage Range | –0.3 to 30 | V |
| Input Current (Continuous) | 1.2 | A |
| Output Current (Continuous) - BAT | 1.2 | A |
| Output Current (Continuous) - LDO | 100 | mA |
| Output Sink Current - CHG | 5 | mA |
| Junction Temperature Range | –40 to 150 | °C |
| Storage Temperature Range | –65 to 150 | °C |
| LDO Output Voltage | 4.7 to 5.1 | V |
| Charge Current Regulation Accuracy | 7% | |
| Input Over-Voltage Protection (VOVP) | 10.5 | V |
| Battery Overcharge Voltage (VBAT(OVCH)) | 3.7 | V |
| Battery Float Charge Voltage (VBAT(FLOAT)) | 3.5 | V |
Key Features
- Programmable Charge Current: Up to 1A using the CTRL input.
- Integrated LDO: 4.9V ±10% 50mA low dropout linear regulator for external circuitry.
- Thermal Regulation and Protection: Internal control loop monitors IC junction temperature and reduces charge current if temperature threshold is exceeded.
- Soft-Start Feature: Reduces inrush current during startup.
- Input Over-Voltage Protection (OVP): Disables charging and LDO output if input voltage exceeds 10.5V.
- Under-Voltage Lockout (UVLO): Device remains in power down mode until input voltage rises above the UVLO threshold.
- External NTC Monitoring: Monitors battery temperature using an NTC thermistor to prevent over-temperature conditions.
- Charge Status Indicator (CHG): Indicates charge cycles and faults through an open-drain output.
- SINGLE INPUT INTERFACE (CTRL): Enables/disables the device, selects input current limit, and controls other functions.
Applications
- Smart Phones: Ideal for charging LiFePO4 batteries in smartphones.
- Mobile Phones: Suitable for mobile phone battery charging applications.
- Portable Media Players: Used in portable media players that require efficient battery charging.
- Low Power Handheld Devices: Applicable to various low power handheld devices requiring compact and efficient battery charging solutions.
Q & A
- What is the maximum charge current of the bq25070DQCR?
The maximum charge current is up to 1A.
- What type of battery does the bq25070DQCR charge?
The bq25070DQCR charges single-cell LiFePO4 batteries.
- What is the input voltage range of the bq25070DQCR?
The input voltage range is from –0.3V to 30V.
- Does the bq25070DQCR have integrated over-voltage protection?
- How does the bq25070DQCR regulate temperature?
The IC has a thermal regulation loop that monitors the die temperature and reduces the charging current if the temperature exceeds a certain threshold.
- What is the purpose of the CTRL input in the bq25070DQCR?
The CTRL input is used to enable/disable the device, select the input current limit, and control other functions such as extending the TS operation range and disabling VIN-DPM mode.
- Does the bq25070DQCR have a built-in LDO regulator?
- How does the bq25070DQCR indicate charge status?
The charge status is indicated through an open-drain CHG output that signals when the battery is fully charged or if there are any faults.
- What is the purpose of the NTC monitoring function in the bq25070DQCR?
The NTC monitoring function monitors the battery temperature using an NTC thermistor to prevent over-temperature conditions and suspend charging if necessary.
- What are the typical applications of the bq25070DQCR?
Typical applications include smart phones, mobile phones, portable media players, and low power handheld devices.
