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[FAQ] BQ24040 and BQ2404X family TS pin configuration of NTC and TTDM mode

The TS pin has multiple ways that it can be configured. What is the best way to connect it and how?

Hello This also applies to BQ21040, BQ24050 and BQ24090 family of devices. The TS pin options and configurations, the best arrangement will depend on the system requirements. Below is a summary of the modes and configurations. Normal battery Charge -- Connected to NTC thermistor in battery pack to monitor battery temp. 50uA current source will develop a voltage that is monitored by internal voltage comparators. Charge is suspended above 1230mV and below 178mV. If NTC is not used a 10k resistor will enable normal operation. Shutdown – Pull TS pin low to will disable charge. Termination and Timer Disable Mode (TTDM) – Float or drive high to enter TTDM. This mode is similar to a power supply mode. After charge is complete the voltage will remain applied to battery. TTDM Disable – Connect a 237k resistor to ground to disable the TTDM mode. Intended for battery pack removed and TTDM mode in not needed. In this condition charge is suspended and no voltage present. The typical configuration is to connect an NTC / 10k resistor to TS. If the battery pack is removable then TTDM mode to power the device is an option. For additional information see section 8.4.8 and 8.4.9 in data sheet.