Overview
The BQ2002SNTR, produced by Texas Instruments, is a low-cost CMOS battery-charge controller designed for reliable fast charging of nickel-cadmium (NiCd) and nickel-metal hydride (NiMH) batteries. This IC integrates fast charge, optional top-off, and pulsed-trickle control in a single package, making it suitable for both stand-alone and system-integrated charger applications. The BQ2002SNTR ensures safe and efficient charging by monitoring battery voltage and temperature, and it can be configured to terminate fast charge based on various criteria such as peak voltage detection, negative delta voltage, maximum voltage, maximum temperature, and maximum time.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit | Notes |
|---|---|---|---|---|---|
| VCC (Supply Voltage) | 4.0 | 5.0 | 6.0 | V | |
| VBAT (Battery Input Voltage) | 0 | VCC | V | ||
| VTS (Thermistor Input Voltage) | 0.5 * VCC | VCC | V | VTS ≤ VTCO inhibits/terminates fast charge and top-off | |
| VMCV (Maximum Cell Voltage) | 2 ± 5% | V | VBAT ≥ VMCV inhibits/terminates fast charge and top-off | ||
| -∆V (BAT Input Change for -∆V Detection) | -12 ± 3 mV | mV | |||
| PVD (BAT Input Change for PVD Detection) | -2.5 ± 2.5 mV | mV | |||
| TOPR (Operating Ambient Temperature) | 0 | 70 | °C | Commercial | |
| TSTG (Storage Temperature) | -40 | 85 | °C | ||
| TSOLDER (Soldering Temperature) | 260 | °C | 10 sec max. | ||
| ICC (Supply Current) | 250 µA | µA | Outputs unloaded, VCC = 5.1V | ||
| ISB (Standby Current) | 1 µA | µA | VCC = 5.1V, VBAT = VPD |
Key Features
- Fast charge of nickel-cadmium (NiCd) and nickel-metal hydride (NiMH) batteries
- Direct LED output displays charge status
- Fast-charge termination by peak voltage detection (PVD), negative delta voltage (-∆V), maximum voltage, maximum temperature, and maximum time
- Internal band-gap voltage reference
- Optional top-off charge and pulsed-trickle charge rates
- Selectable pulse trickle charge rates
- Low-power mode to reduce system power consumption
- 8-pin 300-mil DIP or 150-mil SOIC package options
- Charge inhibit feature using the INH pin
- Battery voltage and temperature monitoring
Applications
The BQ2002SNTR is suitable for a variety of battery charging applications, including:
- Portable electronic devices such as cordless phones, power tools, and handheld games
- Automotive systems requiring NiCd or NiMH battery charging
- Industrial equipment and appliances that use rechargeable batteries
- Consumer electronics with rechargeable battery packs
Q & A
- What types of batteries does the BQ2002SNTR support?
The BQ2002SNTR supports both nickel-cadmium (NiCd) and nickel-metal hydride (NiMH) batteries.
- How does the BQ2002SNTR terminate fast charging?
Fast charging is terminated by peak voltage detection (PVD), negative delta voltage (-∆V), maximum voltage, maximum temperature, and maximum time.
- What is the purpose of the INH pin on the BQ2002SNTR?
The INH pin is used to inhibit fast charging. When the INH pin is high, it suspends the fast charge in progress, and when it returns low, the IC resumes operation from the point where it was suspended.
- How does the BQ2002SNTR monitor battery temperature?
The BQ2002SNTR monitors battery temperature using an external thermistor connected to the TS pin. The temperature sense voltage input at TS is developed using a resistor-thermistor network between VCC and VSS.
- What are the package options for the BQ2002SNTR?
The BQ2002SNTR is available in 8-pin 300-mil DIP and 150-mil SOIC packages.
- What is the low-power mode of the BQ2002SNTR?
The BQ2002SNTR enters a low-power state when VBAT is driven above the power-down threshold (VPD), reducing the operating current to less than 1µA.
- How does the BQ2002SNTR indicate charging status?
The charging status is indicated by an LED output, which is driven to the high-Z state for all conditions other than fast charge.
- What are the recommended operating conditions for VCC?
The recommended supply voltage (VCC) is between 4.0V and 6.0V, with a typical value of 5.0V.
- What is the maximum storage temperature for the BQ2002SNTR?
The maximum storage temperature is 85°C.
- Is the BQ2002SNTR RoHS compliant?
