Does anyone know the external OP can be remove or not if customer only attached earphone as output loading?
I saw EVM schematics that there are dual channel OPs connected with Vout R/L and Vin R/L and customer want to skip them for cost reduce.
Thanks.
Hi, Peter,
Ni hao!!!
Unfortunately, in order to drive HP, you need some sort of op amp at the output. You can find this requirement in the tabular data of the d/s:
This shows the minimum output impedance the device can directly drive is 10 kohms.
I would suggest something like the TPA6138D2 which not only can drive HP without any output blocking caps, but it can also be configured as an LPF to reduce the out of band noise from the DAC.
-d2
