The AD8452 combines a precision analogue front-end controller and switch mode power supply (SMPS), pulse-width modulator (PWM) driver into a single IC for high volume battery testing and formation manufacturing. A precision instrumentation amplifier (in-amp) measures the battery charge/discharge current to better than ±0.1% accuracy, while an equally accurate difference amplifier measures the battery voltage. Internal laser trimmed resistor networks establish the in-amp and difference amplifier gains (66 V/V and 0.4 V/V, respectively), and stabilize the AD8452 performance across the rated operating temperature range.
The part is intended for use in battery formation and testing, high efficiency battery test systems with recycle capability, and in battery conditioning (charging and discharging) systems.
Compared to conventional technology, the AD8452 provides 50% more channels in the same amount of space, adding capacity and increasing battery production throughput. The AD8452 uses switching technology that recycles the energy from the battery while discharging, and delivers 10 times more accuracy than conventional switching solutions. The higher accuracy allows for more uniform cells within battery packs and contributes to longer living batteries in applications such as electric vehicles. It also enhances the safety of manufacturing processes by providing better detection and monitoring to help prevent over and undercharging which can lead to battery failures. The AD8452 delivers bill of material (BoM) cost savings of up to 50% for charging/discharging boards and potential system cost savings of approximately 20%. System simulating demonstration boards will be available and can enable lower R&D engineering cost and shorter time to market for test equipment manufacturers.
Desired battery cycling current and voltage levels are established by applying precise control voltages to the ISET and VSET inputs. Actual charge and discharge current levels are sensed (usually by a high power, highly accurate shunt resistor) whose value is carefully selected according to system parameters. Switching between constant current (CC) and constant voltage (CV) loop integration is instantaneous, automatic, and completely transparent to