Category: Hardware
Product Number: LT3097
On our board we have a LT3097 (U42) that drives some analog filters and other low power downstream devices.
See the attached schematic excerpt.
We see that the +ve output is not correct whenever the -ve output is enabled (at ENN_UVN).
We have tried temporarily removing L26 and L27 (output ferrites) and powering downstream circuits from an external supply.
This works perfectly, with the downstream drawing around 40-60 mA from each of the external +5 and -4.5 rails.
We also tried shorting the current limit resistors R150 and R154 but this does not improve the situation.
In addition, removing the ferrites and connecting OUTP to OUTN with a 80 ohm load resistor.
Please - we need some further ideas for debugging this problem.
Thanks
David