SLVSIR8 June 2026 TPS61383-Q1
PRODUCTION DATA
During SOH mode, the TPS61383-Q1 fully turns on the isolation MOSFET Q3 and regulate the gate voltage of the low-side MOSFET Q2 with LO pin. In this way, low side MOSFET operates in saturation area and discharge the backup battery by constant current. TI recommends 500mA discharge current to achieve best accuracy. By sensing the battery open voltage, voltage with discharge current and discharge current, the battery internal resistance Rbat is given by:
where:
According to the recommendation from battery manufacturer, TI recommends to discharge battery with 200mA Idischg for 500ms and then read Vdischg.