Boost converter for high-voltage bias rails
Switching at 700 kHz, the part uses an external diode (no synchronous rectifier) — the inductor and catch diode see the full output voltage, so choose a diode with at least 100 V reverse rating and a Schottky if efficiency matters above 80 %.
Output voltage range and input limits
Minimum input is 2.5 V, maximum 5.5 V — the part runs from a single Li-ion cell, a 3.3 V rail, or a regulated 5 V bus. The output is adjustable via a resistor divider from a 20 V floor to an 85 V ceiling. That 85 V maximum means the switching node rings to roughly the same voltage — layout needs a tight power loop from the inductor through the diode to the output capacitor, with the exposed pad (16-WQFN, 3x3 mm) soldered to a copper plane for thermal relief.