There are several critical signals which require specific care during board design:
- Analog inputs and clock signals:
- Traces should be as short as possible and vias should be avoided
where possible to minimize impedance discontinuities.
- Traces should be routed using loosely coupled 100Ω differential
traces.
- Differential trace lengths should be matched as close as possible
to minimize phase imbalance and HD2 degradation.
- Digital output interface:
- Traces should be routed using tightly coupled 100Ω differential
traces.
- Make sure the LVDS lanes are routed as far as
possible from the analog inputs to minimize
coupling.
- Voltage reference:
- The decoupling capacitors should be placed as close to the device
pins as possible and connected between VREF and REFGND – avoid using vias by having
the capacitors on the same layer as the device.
- Power and ground connections:
- Provide low resistance connection paths to all power and ground
pins.
- Avoid narrow and isolated paths which increase the connection
resistance.
- Add GND layers between power and signal layers in the PCB stack
up.