BUF20820AIDCPR

Video Amps And Modules Overview

The BUF20820AIDCPR is an obsolete Texas Instruments LCD gamma buffer featuring 18 programmable output channels and two dedicated VCOM adjustment channels. It utilizes a 10-bit resolution digital-to-analog converter architecture with rail-to-rail output capability. The device integrates on-chip One-Time Programmable (OTP) memory for voltage storage, eliminating external EEPROM requirements. It operates within a supply voltage range of 7V to 18V for analog circuits and 2.0V to 5.5V for digital logic. Communication occurs via a high-speed two-wire serial interface supporting clock frequencies up to 3.4MHz.

Video Amps And Modules Feature Summary

• Integrates 18-channel gamma correction buffers alongside two programmable VCOM channels for comprehensive TFT-LCD panel driving.
• Features on-chip OTP memory to store gamma voltages, removing the need for external non-volatile storage components.
• Supports industry-standard two-wire serial communication with a high-speed mode enabling clock rates up to 3.4MHz.
• Provides rail-to-rail output swing capabilities with low supply current consumption per channel.

Video Amps And Modules Applications

• TFT-LCD reference drivers requiring precise gamma voltage generation.
• Dynamic gamma control systems allowing real-time voltage adjustments without hardware changes.
• Direct replacement for traditional resistor-based gamma correction solutions in display panels.
• Applications requiring integrated VCOM buffer management alongside gamma outputs.

Video Amps And Modules Procurement Notes

This component is officially classified as obsolete by Texas Instruments. Verification of availability should focus on surplus distributors or secondary markets rather than direct manufacturer allocation. Designers must assess long-term supply risks and consider lifecycle status before finalizing procurement plans for production environments.

Video Amps And Modules Selection Notes

Select this device for applications requiring high channel counts for gamma correction combined with VCOM buffering in a single package. Ensure the design supports the specified 7V to 18V analog supply range and 2.0V to 5.5V digital supply. Verify that the HTSSOP-38 PowerPAD package fits the thermal and spatial constraints of the target PCB layout.

Video Amps And Modules Part Context

The BUF20820 belongs to Texas Instruments' specialized LCD driver family, designed specifically for flat-panel display technologies. It succeeds earlier discrete gamma generation methods by integrating multiple buffered outputs into a single CMOS IC. This integration simplifies board space usage and reduces component count compared to resistor ladder networks.

Video Amps And Modules Replacement Considerations

Official substitutes include the BUF20800, which offers 18 programmable channels and two VCOM channels, and the BUF12800, providing 12 programmable buffers with 10-bit resolution. Designers should evaluate pin compatibility and software interface requirements when transitioning to these alternative devices.

Video Amps And Modules FAQ

How does the BUF20820 handle power-up states for its outputs?

Upon power-up, the device automatically performs a reset. All outputs update to the values stored in the OTP memory if programmed; otherwise, they default to '0000'.

What is the function of the double-register structure in the BUF20820?

The double-register structure allows pre-loading of data into storage registers while maintaining current DAC output values. This enables rapid, simultaneous updating of all channels when the latch pin is activated or a software command is issued.

Can the BUF20820 operate in standard I2C modes?

Yes, the device is fully compatible with Standard mode (up to 100kHz) and Fast mode (up to 400kHz). It also supports a High-speed mode (up to 3.4MHz) which must be explicitly activated via a specific master code sequence.