Can anyone help me find the ADC section on this board?

[Rakalon]

Hi Guys,

I'm trying to locate the ADC section on this board. Would anyone know?

Thank you

 

[Diver300]

The ADC is IC34 in your last photo.
https://pdf1.alldatasheet.com/datasheet-pdf/view/206770/AKM/AK5357.html
You only need to Google the part numbers to find what each function does.

The microphone signals come down the ribbon cable to CN5. They are amplified by the two JRC2100 ICs, which are op-amps. Then the signal goes to IC34. I am fairly sure that there is a big processor on the underside of the board in the area with lots of holes between R20 and C48. That processor will read the signal digitally from IC34.

 

[Rakalon]

Here is the underside of the board.

I can't find the ADC. I'm a total noob to electronics and just a little lost. Could you help locate the actual part number on the boards? Sorry, I know I'm asking a lot

 

[Diver300]

The IC in the circle is the ADC. The part number is AKM5357 and that is what I googled to get the data sheet link that I posted.

 

[Ian Rogers]

Diver300 That would be IC38 Looks like an audio IC...

 

[Diver300]

Diver300 That would be IC38 Looks like an audio IC...

I can't what IC38 is from the numbers on it. I agree that it looks like an audio IC, but I think that it is the power amplifier that drives the headphone socket via the two electrolytic capacitors.

The OP wanted to find the ADC, not the output amplifier.

 

[Ian Rogers]

Its an old 8570 audio codec ic… Cant get that footprint anymore .. The main processor is next to the usb connector is a USB ic. I cant see a "main" processor.

The OP wanted to find the ADC, not the output amplifier.

Quite correct.... I was just admiring your logic....

 

[Diver300]

Its an old 8570 audio codec ic… Cant get that footprint anymore .. The main processor is next to the usb connector is a USB ic. I cant see a "main" processor.

I think that whatever is in the metal can in post #3 is the processor, but I'm not sure.

 

[Jony130]

It looks like the IC38 is this one WM8750

Cirrus Logic Redirect

 

[Diver300]

It looks like the IC38 is this one WM8750

Cirrus Logic Redirect

I would agree that's the one.

It actually contains an ADCs, as well as a DACs, so I'm not sure why the design needs the AKM5357 ADC as well. However, there are lots of possible reasons why separate ICs could be needed.

 

[Rakalon]

Diver300 and Jony130 you two are brilliant! Thank you. This board is part of the Zoom H4n, an audio recorder

Here's another board from it.

 

[Diver300]

I realised it was an audio recorder, as I recognised the microphone arrangement.

Have we answered your questions?

 

[Rakalon]

Yes definitely Diver300

Thanks for helping me

 

[rjenkinsgb]

It actually contains an ADCs, as well as a DACs, so I'm not sure why the design needs the AKM5357 ADC as well. However, there are lots of possible reasons why separate ICs could be needed.

Two channels for the built-in mics (probably IC34 as it's very close to the preamps) and two more for the XLR mic inputs?