Hangzhou Ruimeng Tech MS3814

MS3814 is a TMDS equalizer/driver IC designed to compensate for losses in FR-4 and cable paths to DVI/HDMI connectors. It provides outputs that fully meet DVI/HDMI TMDS requirements. The device can also be used in DVI/HDMI cable applications to extend transmission distance and improve jitter margin on the connector receiver-side cable channel. The on-chip TMDS driver operates either in the standard DVI/HDMI current mode — with no back-termination resistors on the differential outputs — or in a mode with 50% higher output current, where a 200Ω resistor is placed across the differential outputs to achieve 10dB return loss. Conventional DVI/HDMI output drivers suffer from reflections between the connector and the high-impedance DVI/HDMI output. The selectable output current (controlled by the LEVEL pin) enables a back-termination option (e.g., a 200Ω resistor across the differential outputs), which effectively reduces reflections while minimizing output common-mode shift.

The MS3814 operates from a single supply and features 4 identical channels. Clock and data channels can be freely assigned to provide flexible routing to DVI/HDMI connectors. Data rate: 250Mbps to 1650Mbps.

• Equalizes FR-4 PCB microstrip line and high-frequency cable losses: compensates up to 15dB cable loss at 825MHz
• At 1650Mbps, jitter margin <0.25UI PP for channel loss of 0~15dB@825MHz
• Input 50Ω (each side to VCC) ±10%
• Output driver compatible with DVI/HDMI 1.3
• Output amplitude: differential 1050mV PP
• ENABLE pin selects normal operation or power-down mode
• LEVEL pin selects output current level to accommodate back-termination resistor connected or not connected

• Projector DVI/HDMI interface input
• DVI-D/HDMI cable extender modules and active cable assemblies
• LCD display devices