Embedded antifuse NVM: A mission critical IP for display driver ICs

Edward Cheng, Kilopass Technology
EETimes (4/29/2011 4:08 PM EDT)

Antifuse NVM IPs have been used in display driver ICs (DDI) to store critical parameters for analog and image processing circuitry to calibrate out chip-to-chip variations and to meet different requirements of the system integrators.

Uniform display quality depends on the characteristics of panels and accuracy of driving voltage or current levels, and any tolerance must be compensated for. Antifuse NVMs are perfectly suited for the task of permanently recording the following:

• reference parameters for power management and analog circuits,
• calibration information for timing elements and analog-digital converters,
• brightness and color correction tables,
• initialization data for organic materials, as well as
• configuration selection for different features.

Once antifuse NVM programming has been performed in the final stage of system testing, the display module becomes a tuned unit, eliminating the need for additional software configurations. This allows an automated system assembly and ensures reduced production costs.

In addition to pervasive uses in trimming and yield enhancements, another popular use of antifuse NVM is for boot and firmware code storage. Traditionally, microprocessors for display and touch sensor controllers have to employ externally attached EEPROM chips or embedded flash blocks to store control code with the anticipation of frequent updates.

For some designs, however, as development matures, the number of expected code upgrades has decreased to around 5 to 10 times in the life span of the end product. High-density embedded antifuse NVM offering multi-time programmability is a cost-effective alternative to expensive flash-based counterparts.

To satisfy the industry demand for simplified system designs, future trends point to the consolidation of touch screen and display panels and their respective controller ICs. Embedded antifuse NVM plays an integral role in supporting on-chip storage of calibration data to better match the characteristics of individual panel and high-density software code for the touch screen controller.

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