sinara-hw / Waver_FMC

Four channel DC-coupled, 10Vpp capable, 1.5GS/s AWG FMC
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NCV8187AMLEADJTC LDO wrong ADJ voltage. #5

Open tprzywoz opened 1 year ago

tprzywoz commented 1 year ago

NCV8187AMLEADJTC (IC4, IC5, IC6) has ADJ = 1.2 V, not 0.8 V. Currently real outputs are 1.5 V (P1V2D and P1V2A) and 3.5 V (P3V3A) (all outputs limited by dropout) which is about Absolute Maximum Ratings of DAC for 1.2 V power inputs. Fun fact: DAC still works and produces an output signal.

For already manufactured modules, the solution is to short ADJ with OUT for 1.2 V and change value of R37 to 2.7 kOhm for 3.3 V. In new revision we should change part number of LDO to NCV8187AMTWADJTAG (ADJ = 0.8 V)