Overview
The BQ2000SN-B5TR, produced by Texas Instruments, is a programmable, monolithic IC designed for the fast-charge management of nickel cadmium (NiCd), nickel metal-hydride (NiMH), or lithium-ion (Li-Ion) battery packs. This IC is versatile and can be used in single- or multi-chemistry applications, ensuring safe and efficient charging processes. It detects the battery chemistry and applies the optimal charging and termination algorithms to prevent undercharged or overcharged conditions.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 4.0 | 5.0 | 6.0 | V |
| Supply Current (ICC) | - | 0.5 | 1 | mA |
| Sleep Current (ICCS) | - | - | 5 | µA |
| Output High Voltage (VOH) | VCC - 0.6 | - | - | V |
| Output Low Voltage (VOL) | - | - | 0.2 | V |
| High-Impedance Leakage Current (IOZ) | - | - | 5 | µA |
| Sink Current (Isnk) | - | - | 20 | mA |
| Charge Timer Resistor (RMTO) | 2 | - | 250 | kΩ |
| Charge Timer Capacitor (CMTO) | 0.001 | - | 1.0 | µF |
| Maximum Cell Voltage (VMCV) | - | - | 2 | V |
| High-Temperature Cutoff Voltage (VTCO) | 0.225 * VCC | - | - | V |
Key Features
- Safe management of fast charge for NiCd, NiMH, or Li-Ion battery packs.
- High-frequency switching controller for efficient and simple charger design.
- Pre-charge qualification for detecting shorted, damaged, or overheated cells.
- Fast-charge termination by peak voltage (PVD) for nickel chemistries, minimum current for Li-Ion chemistries, maximum temperature, and maximum charge time.
- Selectable top-off mode for achieving maximum capacity in NiMH batteries.
- Programmable trickle-charge mode for reviving deeply discharged batteries and for post-charge maintenance.
- Built-in battery removal and insertion detection.
- Sleep mode for low power consumption.
- Integrated high-speed comparator for high-efficiency battery charger circuits.
Applications
- Multi-chemistry charger.
- Nickel charger.
- High-power, multi-cell charger.
Q & A
- What types of batteries does the BQ2000 support?
The BQ2000 supports nickel cadmium (NiCd), nickel metal-hydride (NiMH), and lithium-ion (Li-Ion) batteries.
- How does the BQ2000 terminate fast charge for different battery chemistries?
The BQ2000 uses peak voltage detection (PVD) for NiCd and NiMH, minimum current for Li-Ion, maximum temperature, and maximum charge time to terminate fast charge.
- What is the purpose of the pre-charge qualification feature?
The pre-charge qualification feature detects shorted, damaged, or overheated cells before initiating the fast charge process.
- How does the BQ2000 manage battery temperature during charging?
The BQ2000 uses an external temperature-sensing circuit with a negative temperature-coefficient thermistor to monitor and control the battery temperature, ensuring safe charging conditions.
- What is the function of the trickle-charge mode?
The trickle-charge mode is used to revive deeply discharged batteries and for post-charge maintenance to keep the battery in a healthy state.
- How does the BQ2000 detect battery removal and insertion?
The BQ2000 has built-in detection for battery removal and insertion, which helps in managing the charging process accordingly.
- What is the purpose of the sleep mode in the BQ2000?
The sleep mode reduces power consumption when the device is not actively charging, enhancing overall efficiency.
- How does the BQ2000 control the charging current?
The BQ2000 controls the charging current through a hysteretic control loop, regulating it based on the voltage drop across an external sense-resistor connected in series with the battery pack.
- What is the significance of the high-speed comparator in the BQ2000?
The high-speed comparator allows the BQ2000 to be the basis for a complete, high-efficiency battery charger circuit for both nickel-based and lithium-based chemistries.
- What are the typical operating conditions for the BQ2000?
The BQ2000 operates within a supply voltage range of 4.0V to 6.0V and an operating temperature range of -20°C to 70°C.
