Overview
The TMDS261B, produced by Texas Instruments, is a two-port digital video interface (DVI) or high-definition multimedia interface (HDMI) switch. This device allows up to two DVI or HDMI ports to be switched to a single display terminal, supporting resolutions up to 1080p with 16-bit color depth. It is designed for signaling rates up to 3 Gbps and complies with the HDMI 1.3a specification. The TMDS261B features an adaptive equalizer to compensate for intersymbol interference (ISI) loss in HDMI/DVI cables, making it suitable for various high-definition display applications.
Key Specifications
| Parameter | Min | Nom | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 3 | 3.3 | 3.6 | V |
| Operating Temperature (TA) | 0 | - | 70 | °C |
| TMDS Data Rate | - | - | 3 | Gbps |
| TMDS Differential Output Voltage (VID(pp)) | 0.15 | - | 1.56 | V |
| TMDS Input Rise and Fall Time (tIN_Rise_Fall) | 75 | - | - | ps |
| Termination Resistance (RT) | 45 | 50 | 55 | Ω |
| I2C Data Rate (dR(I2C)) | - | - | 100 | Kbps |
| Package Type | - | - | 64-pin TQFP | - |
| Junction Temperature (TJ) | 0 | - | 125 | °C |
Key Features
- 2:1 Sink-side Switch: Supports switching between two DVI or HDMI ports to a single display terminal.
- Adaptive Equalization: Automatically compensates for intersymbol interference (ISI) loss in HDMI/DVI cables up to 20 dB at 3 Gbps.
- TMDS Input Clock-Detect Circuit: Provides automatic power-management by disconnecting terminations and placing TMDS outputs in a high-impedance state if no valid TMDS clock is detected.
- DDC Repeater Function: Buffers the DDC I2C interface for each input port, isolating source-side capacitance from the sink side.
- Low-Power Mode: Consumes less than 2 mW in low-power mode, with all inputs and outputs disabled except for internal I2C logic and the LP pin.
- Local I2C or GPIO Configurable: Allows configuration via either a local I2C interface or GPIO interface.
- Enhanced ESD Protection: Human Body Model (HBM) ESD protection up to 10 kV on all input TMDS, DDC I2C, and HPD pins.
- 3.3-Volt Power Supply: Operates from a single 3.3-V supply voltage.
- Robust TMDS Receive Stage: Can work with non-compliant input common-mode HDMI signals.
Applications
- High-Definition Digital TV: Supports high-definition resolutions and signaling rates.
- LCD, Plasma, and DLP Displays: Compatible with various display technologies.
- Consumer Electronics: Ideal for use in consumer electronics requiring high-definition video switching.
Q & A
- What is the primary function of the TMDS261B?
The TMDS261B is a two-port digital video interface (DVI) or high-definition multimedia interface (HDMI) switch that allows switching between two DVI or HDMI ports to a single display terminal.
- What signaling rates does the TMDS261B support?
The TMDS261B supports signaling rates up to 3 Gbps.
- What is the purpose of the adaptive equalizer in the TMDS261B?
The adaptive equalizer compensates for intersymbol interference (ISI) loss in HDMI/DVI cables up to 20 dB at 3 Gbps.
- How does the TMDS261B manage power when no valid TMDS clock is detected?
The TMDS261B disconnects the terminations on the input TMDS data lines and places the TMDS outputs in a high-impedance state when no valid TMDS clock is detected.
- What is the DDC repeater function in the TMDS261B?
The DDC repeater function buffers the DDC I2C interface for each input port, isolating source-side capacitance from the sink side.
- How can the TMDS261B be configured?
The TMDS261B can be configured via either a local I2C interface or GPIO interface.
- What level of ESD protection does the TMDS261B offer?
The TMDS261B offers Human Body Model (HBM) ESD protection up to 10 kV on all input TMDS, DDC I2C, and HPD pins.
- What is the power supply requirement for the TMDS261B?
The TMDS261B operates from a single 3.3-V supply voltage.
- What are the typical applications of the TMDS261B?
The TMDS261B is typically used in high-definition digital TVs, LCD, plasma, and DLP displays, and other consumer electronics requiring high-definition video switching.
- What is the package type of the TMDS261B?
The TMDS261B is available in a 64-pin TQFP package.
