Low Power Battery Backup IC with Integrated Boost Converter

The TPS65510 offers a suitable solution for power switch to select the main battery or the backup battery.

This device automatically selects the power path. It depends on the voltage level of the VOBT pin. When the main battery is removed, the power path of the VOUT pin is automatically changed from the output of 3.3-V low droppout (LDO) voltage regulator to the backup battery.

The backup battery is charged from the power path of the VRO pin (output of 3.3-V LDO) via an external diode and resistor. The input of the LDO voltage regulator comes from the internal boost converter.

The 1.2-V output LDO and 1.8-V output LDO voltage regulators have a enable pin, VCTRL. If these outputs are not necessary, VCTRL should be connected to AGND to save power consumption. The self-power consumption is less than 3 µA (maximum) using the backup battery.

This device has two indicators. One is CS, which monitors the voltage level of the VBAT pin and VOBT pin. The other is XRESET, which monitors voltage level of the VOUT pin. These indicators should be connected to CPU/DSP to reset them.

This device reduces the total solution area and extends the lifetime of the backup battery.