The bq2018 is a low-cost charge/discharge counter that works with an intelligent host controller to provide charge and discharge information for rechargeable batteries. It has various features, including internal offset calibration for improved accuracy, NVRAM registers for capacity monitoring, and a single-wire serial interface. It can operate in different modes and has an internal timebase, making it suitable for battery pack integration.
The bq2018 is a multifunction charge/discharge counter peripheral designed to work with an intelligent host controller to provide state-of-charge information for rechargeable batteries. It measures the voltage drop across a low-value series sense resistor between the negative terminal of the battery and the battery pack ground contact. The device features 1024 bits of NVRAM configured as 128x8 and includes an internal temperature sensor for self-discharge estimation.
Packaged in an 8-pin TSSOP or SOIC, the bq2018 is small enough to fit in the crevice between two A-size cells or within the width of a prismatic cell. It operates from a single-wire serial interface and offers dual operating modes: Operating mode with current less than 80uA and Sleep mode with current less than 10uA. A REG output is available for low-cost microregulation.
| Resolution | less than 12.5uV |
|---|---|
| NVRAM Size | 1024 bits (128x8) |
| Operating Current | less than 80uA |
| Sleep Current | less than 10uA |
| Package Options | 8-pin TSSOP or SOIC |
| Supply Voltage (Regulated) | 3.7V nominal |
| Supply Voltage (Unregulated) | 2.8V to 5.5V |
| Charge Count Rate | 12.5uV per hour |
| Discharge Count Rate | 12.5uV per hour |
| Self-Discharge Count Rate | 1 count per hour at 25C |
The bq2018 is a low-cost charge/discharge counter peripheral packaged in an 8-pin TSSOP or SOIC that works with an intelligent host controller.
It measures the voltage drop across a low-value series sense resistor between the negative terminal of the battery and the battery pack ground contact.
The RBI input operates from an external power storage source to provide register nonvolatility when the battery is shorted or charge is insufficient.
The operating current is less than 80uA, and the sleep mode current is less than 10uA.