5# Technical Documentation: DS90UR907QSQENOPB Serializer
Manufacturer : NSC (National Semiconductor)
## 1. Application Scenarios
### Typical Use Cases
The DS90UR907QSQENOPB is a 21-bit to 10-bit FPD-Link III serializer designed for high-speed video data transmission in automotive and industrial applications. Typical use cases include:
- Automotive Camera Systems : Primary application in surround-view and backup camera systems
- Driver Assistance Systems : Integration with ADAS (Advanced Driver Assistance Systems) for forward-facing and side-view cameras
- High-Resolution Displays : Support for video resolutions up to 1080p at 60Hz
- Long-Distance Video Transmission : Capable of transmitting video data over 15 meters using standard coaxial cable
### Industry Applications
- Automotive Industry : Camera modules for parking assistance, blind spot detection, and collision avoidance systems
- Industrial Vision Systems : Machine vision cameras requiring robust data transmission
- Medical Imaging : Endoscopic and diagnostic imaging equipment
- Surveillance Systems : High-resolution CCTV and security camera systems
### Practical Advantages and Limitations
Advantages:
- EMI Performance : Utilizes FPD-Link III technology with embedded clock for reduced EMI
- Power Efficiency : Low power consumption (typically 75mW) suitable for battery-operated systems
- Robustness : Built-in DC-balanced encoding for improved signal integrity
- Cable Reduction : Single coaxial cable carries video, control, and power (when using PoC)
- Temperature Range : Operates from -40°C to +105°C for automotive applications
Limitations:
- Fixed Configuration : Limited to specific pixel clock frequencies (25MHz to 85MHz)
- Complexity : Requires matching deserializer (DS90UR908) for complete system
- Cost Consideration : Higher per-channel cost compared to parallel interfaces
- Cable Requirements : Requires controlled impedance cables for optimal performance
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Improper Power Sequencing
- Issue : Damage from incorrect power-up sequence between serializer and deserializer
- Solution : Implement proper power management with controlled ramp rates and sequencing
Pitfall 2: Signal Integrity Problems
- Issue : Excessive jitter or signal degradation in long cable runs
- Solution : Use controlled impedance cables (100Ω differential) and proper termination
Pitfall 3: EMI Compliance Failures
- Issue : Radiated emissions exceeding automotive standards
- Solution : Implement proper shielding and follow recommended PCB layout guidelines
### Compatibility Issues
Component Compatibility:
- Required Pairing : Must be used with compatible deserializer DS90UR908
- Camera Sensors : Compatible with common automotive image sensors (OV10640, AR0144, etc.)
- Power-over-Coax : Requires compatible PoC circuitry for single-cable implementations
Interface Compatibility:
- Input Interface : 21-bit parallel RGB with control signals
- Output Interface : Single LVDS serial stream with embedded clock
- Control Channel : I²C backward channel for bidirectional communication
### PCB Layout Recommendations
Power Supply Layout:
- Use separate power planes for analog (3.3V) and digital (1.8V) supplies
- Implement proper decoupling: 10μF bulk capacitor + 0.1μF ceramic capacitor per power pin
- Place decoupling capacitors within 2mm of power pins
Signal Routing:
- LVDS Output : Route as 100Ω differential pair with length matching (±5mil)
- Parallel Inputs : Keep trace lengths short and matched for data lines
- Clock Signals : Isolate pixel clock from sensitive analog circuits
