There has been a push for a small LCD display module as more and more products have become portable and battery powered. There are four types of LCD technologies that continue to reduce in size and power consumption.
Small Segment LCD:
Size: 20.8 x 21.3 mm
Segment LCDs are used on gas pumps, scales and clocks. They can display numbers, some letters and custom Icons. In the past few years, the cost to customize a segment display has dropped in price. Custom segments allow the customer to choose the exact size they need and the numbers and icons they want.
It is possible to build these in a small size. The challenge is that the smaller the segment LCD, the higher the MOQ (Minimum Order Quantity).
Static displays can be built with or without a LCD backlight and the backlight can be turned ON and OFF independently from the LCD.
Small Character LCD:
Size: 45.0 x 20.0 mm
It is possible to custom build a character LCD, but in most cases, a standard, off-the-shelf character LCD will work. The smallest character LCD is eight characters by one row (8x1). However, if you compare the LCD dimensions we have a 16x2 which is actually smaller than our 8x1. The module size of this 16x2 character LCDi s 45.0 x 20.0 mm.
Character LCDs can display any letter, number and punctuation mark.
They can be built with or without a LED backlight that can turned on and off independently of the LCD to save power (battery life).
Small Graphic LCD:
Monochrome graphic displays have reduced in size in the last few years. They use rows and columns of dots to create images and through software can display letters, numbers, punctuation marks and images.
Monochrome means that they have one color letter/character and a different color background. Common color configurations include blue/white, black/white, and yellow/green.
Graphic displays can be built with or without a LED backlight to make them readable at night.
Small color TFT display:
Size: 34.0 x 47.0 mm
TFTs (Thin Film Transistor) are very popular since they can display all the information that a monochrome graphic can, but in over 64,000 unique colors.
The cost to customize a TFT is very expensive ($100K+) and the MOQs are very high. So, if the standard sizes can work for you, this could be a very good solution to add value to your product.
If you need multi color displays, it is best to work your design around the current standard sizes of the TFT displays.
Keep in mind, the backlight must be on for the TFT to be readable which will cause a power drain.
Power for small LCD display module
With the development of low-power processors, most small LCDs can now run on 3.3V with very little current draw.
Note: When adding a LED backlight, the backlight alone may require almost 10x the power required for the LCD alone.
To maximize the battery life of a small LCD display module, only use the backlight for short periods of time. If you are using a TFT, have the entire display shut off or dim after a few seconds.
So, what is the story about OLEDs. (organic light-emitting diode ). They are very thin, provide sharp, bright colors, use very little power and can operate to very low temperatures. But at this time, we are not recommending OLEDs for many new designs since their lead-time has been increasing due to their popularity.
Have a great new idea, but not sure what LCD to choose? Make a cup of coffee (or Tea) and give us a call at 480-503-4295