I use MP2617 for our design - telematics dongle. Please help me on below questions.
1. Vin = 5V (from 5V - 3A DC/DC power). Vin_lim is set at 4.65V, is it ok ?
2. I am not clear about input voltage limit function.
- With Vin = 5V, if Vin_lim is set > 5V - what happen ?
- With Vin = 5V, if Vin_lim is set < 5V - what happen ?
3. In datasheet, "When the voltage on VLIM pin hits the reference voltage of 1.52V, the output of the input voltage limit error amplifier will drop in to control the operation duty. In this mode, the input voltage will be clamped according to the value set by the resistor divider"
- What mode is in normal condition, VLIM pin > 1.52V or VLIM < 1.52 V ?
- Input voltage will be clamped - you mean Vin will be clamped ?
4. In our current design, Vin = 5V, Vin_lim = 4.65 V, Vsys = 4V, L = 1.2uH, Cout = 22u.
- Big ripple in Vsys (attached waveform), without battery inserted.
- Vin = 5V , adjust VILIM pin voltage > 1.52V.
- Vin = 5V, adjust VILIM pin voltage < 1.52V.