Can the TPS43060 be used as an asynchronous boost circuit with a diode in place of the high-side FET? This is to disconnect the SW pin and boost circuit from the switching node thus avoiding the output voltage limitations. I did not see any warnings about this and the simplified schematics imply the boost circuit is a self-contained module that does not feed to other parts of the chip.
I ran three tests:
- The switch node fed back to the SW pin and boost capacitor through a 10kΩ resistor. This produced a low-pass version of the switch node on the SW pin with no ringing, overshoot, etc.
- The switch node fed back to the SW pin and boost capacitor through a 10kΩ/10kΩ divide-by-two voltage divider, so the 50 volt output was a filtered 25 volts on the SW pin.
- The link between the switch node and the SW pin and boost capacitor was disconnected entirely, and the SW pin was tied to ground through a 10kΩ resistor.
The diode got about 10C hotter than the FET did. Everything seemed to work fine, and the voltage waveform on the switch node looked the same.
