Hello guys,
i am currently trying to get an LTC4020 based battery charger board to work. Its the first prototype so maybe there are some mistakes in the current design.
I did not connect a battery in my test setup.
The problem is, that the LTC4020 only outputs a voltage of around 1.8V while no NTC is connected! The voltage on the NTC-Pin is around 2V in this case.
Connecting a 10k NTC results in the same behavior -> Output voltage of the converter is still only ~1.8V. Voltage on the NTC node is around 0,53V with connected 10k NTC.
Shorting the NTC pin to ground immediately increases the output voltage to the desired voltage set by the VFBmax resistor divider and all seems to work fine...
There is really nothing attached to the NTC-Pin on the board! There is just a single trace going to a connector.
What could be the reason for that?
If i understand the datasheet correctly on NTC faults the battery FET should get disconnected and the voltage on the output should raise up to the converter safety limit set by the resistor divider on VFBmax? But why i need to short the NTC node to GND in order to start the converter?
Kind Regards
Danie
