Dear Sirs,
We have some problem with power save mode of TPS63070 in our device. Our device has been in production for several months, and a few days ago we notice a problem, because our customer wants to change a standard power supply (so far it was 12V) to 15V. We assumed that the input voltage range is from 9V to 16V (16V is the maximum input voltage of TPS63070), output voltage of TPS63070 is set to 3.3V. Current consumption isn't constant. When radio module transmits data it is about 130mA, otherwise a few mA, so the average current consumption is about 15-20mA (depends on input voltage). When exetrnal supply fails, the device is supply from internal backup battery (LiFePO4 3.2V). The TPS63070 has enough wide input voltage range. It works fine only to 13.5-14V of power supply. Above 13.5V-14V power save mode doesn't work. Once TPS63070 switches to PWM mode, it remains in PWM mode forever. So the averange current consumption increased from 15-20mA (at 9-13.5V of input voltage) to more than 50mA (at input voltage >13.5V) and is not accepted.
I appreciate any suggestion why it works so strange.