Moving from CCFT- to LED-backlit LCD modules

Making the transition

Companies like Sharp are working to ease the transition by introducing upgrade LCD modules that are as close to a “drop-in replacement” for their CCFT-counterparts as possible.

Whenever Sharp is forced to discontinue a CCFT-backlit module and replace it with an LED-backlit one, extensive research is performed to properly map form, fit, and function issues between the discontinued module and its upgrade.

Often, the upgraded module will be slightly thinner and slightly lighter due to the LED strip requiring less space and less mechanical reinforcement. While most customers do not find this a drawback, designers should always be aware of these differences and how it may affect their particular design.

In all cases where there are differences in the upgraded module, these differences will be called out in Sharp's Product Change Notice document.

These items are also reviewed for compatibility:

• Electrical - the connectors will typically be the same and have similar functionality, unless otherwise stated.

• Hardware-based display functions - such as Display Invert and Display Reverse are typically supported, using the same combinations of pin voltages.

• Driver availability - many third-party driver manufacturers have built replacement backlight drivers for LED-based modules to be 'drop-in' replacements for existing CCFT inverter units; these units are made to utilize the same power supplies with minimal modifications to the existing design.

• Built-in LED drivers - Sharp is building many modules (many as upgrades) with built-in LED backlight drivers, so designers need not consider the expense of replacing a CCFT inverter with a standalone back- light driver. Sharp’s upgrade modules come with a built-in advantage in backlight drivers that are designed to be compatible with common CCFT driver supply voltages, backlight ON/OFF signals, and PWM dimming signals.