+3.3V Programmable LVDS Transmitter 24-Bit Flat Panel Display (FPD) Link-65 MHz [Life-time buy]# DS90C383AMTD Technical Documentation
*Manufacturer: National Semiconductor (NS)*
## 1. Application Scenarios
### Typical Use Cases
The DS90C383AMTD is a high-speed LVDS (Low-Voltage Differential Signaling) serializer designed for converting 21 bits of CMOS/TTL data into three LVDS data streams. Typical applications include:
- Flat Panel Display Interfaces : Primary application in LCD/OLED display systems for transmitting RGB data, control signals, and clock information
- Digital Video Transmission : High-speed serialization of video data streams in consumer electronics and professional video equipment
- Embedded Display Systems : Integration into industrial HMI panels, medical displays, and automotive infotainment systems
- Camera and Sensor Interfaces : High-bandwidth data transmission from imaging sensors to processing units
### Industry Applications
- Consumer Electronics : High-definition televisions, digital signage, gaming consoles
- Automotive : Center stack displays, digital instrument clusters, rear-seat entertainment
- Medical Imaging : High-resolution medical monitors and diagnostic display systems
- Industrial Automation : Machine vision systems, control panel interfaces, process monitoring displays
- Avionics : Cockpit displays and in-flight entertainment systems
### Practical Advantages and Limitations
Advantages:
- High Noise Immunity : LVDS differential signaling provides excellent common-mode noise rejection
- Low EMI : Reduced electromagnetic interference compared to parallel CMOS interfaces
- Power Efficiency : Low power consumption (typically 75mW at 3.3V supply)
- High Speed : Supports pixel clock rates up to 85MHz, enabling high-resolution displays
- Cable Reduction : Significant reduction in cable count and connector size compared to parallel interfaces
Limitations:
- Complex Termination : Requires precise termination resistors (100Ω differential) for signal integrity
- PCB Layout Sensitivity : Demands careful board design to maintain signal integrity
- Limited Cable Length : Practical cable lengths typically limited to 5-10 meters depending on data rate
- Power Sequencing : Requires proper power-up/down sequencing to prevent latch-up
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Improper Termination
- Issue : Missing or incorrect termination resistors causing signal reflections
- Solution : Place 100Ω differential termination resistors as close as possible to receiver inputs
Pitfall 2: Power Supply Noise
- Issue : Inadequate power supply decoupling leading to signal integrity problems
- Solution : Implement proper decoupling with 0.1μF ceramic capacitors placed near power pins
Pitfall 3: Grounding Issues
- Issue : Poor ground return paths causing common-mode noise
- Solution : Use solid ground planes and ensure proper grounding for both transmitter and receiver
Pitfall 4: Clock Skew
- Issue : Clock-to-data skew affecting synchronization
- Solution : Maintain matched trace lengths for clock and data pairs
### Compatibility Issues
Input Compatibility:
- Compatible with 3.3V CMOS/TTL logic levels
- Requires proper level shifting for 5V systems
- Inputs are not 5V tolerant
Output Compatibility:
- LVDS outputs compatible with DS90C384 and similar LVDS deserializers
- Requires LVDS-compliant receivers; not compatible with RS-485 or other differential standards
Power Supply Considerations:
- Single 3.3V supply operation
- Not compatible with 5V or lower voltage systems without level translation
### PCB Layout Recommendations
Differential Pair Routing:
- Maintain consistent differential impedance (typically 100Ω)
- Keep differential pairs closely coupled with minimal spacing variations
- Route differential pairs on the same layer whenever possible
Length Matching:
- Match trace lengths within differential pairs (±10 mil
