Insufficient decoupling on THS4541s and OPA857s
The datasheet includes some quite demanding decoupling requirements (pp. 33, 49). Specifically, they mention:
- Bulk (2.2u - 6.8u) capacitors near the device
- <0.1″ from the 100n capacitors to the pads
They also mention using X2Y caps but that would be overkill, we only use a fraction of the component's range. I do think, however, that it would be relevant in the frequencies that we operate on to:
- Add the bulk capacitor nearby
- Make both decoupling caps 100n, as the datasheet recommends (currently one is 10n)
- Change the 0603 size to 0402 for somewhat better inductance and easier placement
- Mount them on the component's side