Why Serial Links Are Needed
Board-level interfaces like MIPI CSI-2 reach only ~30cm, while camera-to-domain-controller wiring commonly exceeds 5 meters, even 15. A serializer/deserializer pair (SerDes) packs MIPI signals into high-speed differential serial streams, carrying video, control and power over one coaxial cable across the distance.
Core Parameter Comparison
| Dimension | GMSL2 (ADI/Maxim) | FPD-Link III (TI) |
|---|---|---|
| Forward rate | 6Gbps | 4.16Gbps (953/954) |
| Cable | 50Ω coax / STP | 50Ω coax / STP |
| Distance | 15m class @6Gbps | 10m class @4.16Gbps |
| Reverse channel | 187.5Mbps control channel | I2C/UART passthrough |
| PoC | Supported | Supported |
| Typical devices | MAX9295A/9296A | DS90UB953/954 |
| Platform ecosystem | NXP, NVIDIA, etc. | TI TDA4, some Qualcomm |
How to Choose
Follow the domain-controller platform — the most practical decision path:
- Whichever deserializer the SoC's reference design uses, the camera side gets the matching serializer
- For 8MP+ high-bandwidth long-distance scenarios, GMSL2's 6Gbps headroom is larger
- Teams with existing TI platform production and debugging experience migrate to FPD-Link at the lowest cost
- For fleet-level operations such as online diagnostics and link-status reporting, GMSL2's link diagnostics are more complete
Engineering Notes
- PoC filter network: supply ripple couples into the video band; the cutoff-frequency design of both ends' filters is the key to stability
- Connector impedance continuity: cable-connector-PCB impedance discontinuities are the main source of bit errors — TDR verification is recommended
- EMC: when serial-link harmonics fall in FM/DAB bands, focused remediation is needed; plan routing and shielding early
TSIMSAFE provides modules and reference designs for both GMSL2 and FPD-Link III — see the GMSL2 High-Speed Serial Link Solution.
#GMSL2#FPD-Link#串行传输#技术分享
