| IP개요 |
This IP presents a real-time state-of-charge (SoC) indicator for stackable litium-ion (Li-ion) batteries. Based on the equivalent circuit model (ECM) of Li-ion batteries, the proposed indication method estimates the internal resistance (RIN) by detecting battery voltage variations caused by parallel sensing resistor (RS). Compared to conventional SoC indicators that employ series RS and power-hungry high-precision ADCs, the proposed indicator operates with low-power, high precision by utilizing parallel RS along with the battery RIN estimation (BRE) algorithm. The proposed indicator estimates the RIN of a battery, ranging from 7 mΩ to 320 mΩ, based on the voltage range of each 4-stacked Li-ion battery, from 2.5 V to 4.3 V. The proposed indicator achieves a maximum estimation error rate of 2 %. The proposed converter is implemented in TSMC 180 nm BCD process, with a chip area of 3x2.5 mm2. |
