DC2132A Power Supply problems

[FotatoPotato]

Hi all,

So I just finished building my own version of the Analog Devices DC2132A bench power supply. All I really changed was the physical layout of the board to fit my needs, otherwise, there have been no changes to the schematic but I'm experiencing some issues.

While both the voltage and current control work I am only able to go up to about 2.8v on the output of the linear regulators and the output of the DC-DC buck converter maxes out at 4.12v with a 31v input. I have looked around the schematic and probed the board to see if I could find anything that is wrong but I just can't seem to find anything wrong. I'll link both the reference schematic and my re-creation in Altium so that you guys can take a look and see if you can find something. If you guys have any questions on the design please let me know and if you find any faults, please let me know.

Thanks! 

[perieanuo]

[edited]
hi,
I don't get how you implemented dcdc with LTC3632(in his datasheet you input voltage to Vin pin, referenced to Gnd pin 8 and you 'take out' voltage after inductor connected on SW pin, also referenced to pin 8 ).
In your shhematic you apply between Vin and some floating virtual GND and you output between that virtual gnd and the load GND.you made an -5V for some purpose?
I don't see inductive load protection, Q1 may be the first to hit the bucket
Let's come to the point, purpose of D5 is doing what?
The tell us what voltage you have on LT3081/SET and Vout, when R31 is 0 with Ilim at max or disconnected and no load. 
regards

[perieanuo]

hi, on second verification, I think D5 has no place there, remove it an tell the result.

[FotatoPotato]

Hey perieanuo,

Thanks for the reply! Unfortunately, I can't simply remove U5, It's needed to set the voltage on the v-limit potentiometer and it directly determined the output, however now I'm thinking that the problem lies in U5 and maybe it isn't supplying the correct voltage....

I'll check and see if there is something wrong.

Thanks!