The LT5176 buck boost converter outputs a short 90-91 volt spike at at the output in the 2nd second after startup, applying power to Vin.
More details at Why does this buck boost with dual MOSFETs fails output at certain input voltages at light load? (board is populated with single MOSFETs: 4 pieces)
- 100 kHz LMG95 (Zes-Zimmer precision power meter)
- Input resistance: 1MOhm, 20pF
- 50 cm cable
- clip probe tip
- this overvoltage spike happens at all input voltages (33-55V)
- this overvoltage spike happens at different loads (1ma, 10ma, 100ma, 1000ma)
- also happens unloaded
Is it normal to measure such a voltage spike at the output? In case this is expected behaviour, why? Which design/IC would not suffer from a short overvoltage spike on startup?