My ADS Doesn't Have +12V Output

[Leo_W]

Hi, 

My Analog Discovery studio has -12V, 3.3V, 5V output. But no +12V ouput. I unpacked the ADS cover to find the +12V without schematic because I can't find the schematic on the official website. I want to find the power tree circuit. So I can figure out which ic gives the +12V output from the 15V input. Is it possible to let me know the part power tree circuit of +12V or let me know how to repair it?

[JColvin]

Hi @Leo_W,

I have moved your question to a more appropriate section of the Forum where the engineer most familiar with the Analog Discovery Studio will be able to see and respond to your question.

Thanks,
JColvin

[attila]

Hi @Leo_W

I don't have too much experience with the ADS, I only have a prototype of this.

The driver and protection circuit is the following and it is next to the 15V socket.

@malexander Are you aware of any issues with the +12V rail ?

[Leo_W]

On 6/25/2020 at 3:40 PM, attila said:

Hi @Leo_W

I don't have too much experience with the ADS, I only have a prototype of this.

The driver and protection circuit is the following and it is next to the 15V socket.

@malexander Are you aware of any issues with the +12V rail ?

Thanks for this circuit. I measure every pin of the IC10, there is no output for the USR_VCC12V0 and I find that the EN pin is 1.5V, which should be 5V. This pin should be the energize for IC10 to work. However, I don't know where is the PGVCC 5V comes from.

 

[attila]

Hi @Leo_W

The PGVCC5V0 is fine, it should be about 1.6V ( >1.3V )
Probably the IC10 is damaged.

[malexander]

PGVCC5V0 is created using a resistor divider off the VCC5V0 supply output. The divider creates a voltage of ~1.598 (assumes ideal resistors and infinite input impedance on all loads), which is plenty high to exceed the enable threshold of the ADP7118 (1.3V max). If you are measuring anything between 1.5V and 1.6V then there's nothing wrong with the PGVCC5V0 net. If USR_VCC12V0 is measuring 0V then IC10 must be damaged or there must be a short circuit downstream of that device. The VCC12V0 output is tested as part of the manufacturing test so the unit should have failed testing if that supply wasn't functioning prior to the unit being shipped.