Choosing Low-Cost, Low-Power LCD's For Handheld Products
Let’s face it. We don’t like being tied down. I’m not talking about being married or having to sign a three-year contract for a health gym. I’m talking about our lifestyle becoming increasingly more mobile.
Phones are cordless, remote controls are cordless, you can even start your car with a cordless product.
We are the cordless generation.
This is true for people living in America and in Bolivia. It’s true for a five-year old watching a cartoon on his father’s tablet at the grocery store and it’s true for a senior checking their blood pressure with a small, single battery powered digital meter.
None of us want to be tied down - a good thing. This desire for freedom is fueling the need for more products to lose the cord and morph to mobile, handheld product.
The primary goal for new product development is no longer how small something can be made, or how cheap (although that is important). The new primary goal is to develop handheld products that extend the life of the battery. Sure, last year’s model lasted seven hours before needing a charge, so this year we are pushing for eight or nine hours. What is your competitor going to offer?
The quest for designers is to choose a LCD technology with the smallest hunger for electrons. So, let’s target the one component with the most unquenchable thirst for power: The LCD display.
Two excellent display products meeting this criteria are: Segment and Character LCDs. Both are:
Tend not to be obsoleted
Even with sexy, bright, colorful display technologies like TFTs and OLEDs, Segments and Characters are still the preferred choice for many new handheld products.
Segment LCD Displays:
Segment LCDs, aka glass only, are custom modules. For one low tooling cost, the display is built to the size you want. MOQs (Minimum Order Quantities) start around 1K units per build, but prices are so low, it allows you to purchase several thousand with very little investment. This is a great benefit for new product development where cost containment is critical.
A LED backlight can be added, but try to minimize its use since these portable flashlights draw ten times more power than the LCD alone.
They are the perfect match for ‘AA’ battery powered products since they can be driven at 3.3V.
Character LCD Displays
Character LCDs, aka alphanumeric, can operate 3.3V with as little as 1 mA current. Another great match for battery power products.
They are standard, stock items which means you can buy one or one thousand and your purchasing department will not be stuck with very long, ugly lead-times or a discontinued display.
Character displays have the standard option of adding a LED backlight for nighttime operation. Just be aware that they can drain anywhere from 15mA to 50mA depending on the size of the glass and brightness. A little PWM (Pulse Width Modulation) can work wonders for improving the appearance of your product.
If your backlight will be on all the time, choose a transmissive polarizer to achieve a brighter backlight without any additional current drain. Design engineers prefer character modules since they contain a built-in controller/driver with an eight-bit interface. You can even get away with a four-bit option if you are running short on I/Os.
Choosing the correct character LCD is simple, here is all you need to know:
Step 1. Choose the number of characters you need.
Choices are: 8x1, 8x2, 16x1, 16x2, 20x2, 20x4 and 40x4
Step 2. Choose the overall size of the LCD.
Step 3. Choose a voltage: 5V (good for low temperatures) and 3.3V (good for batteries)
Step 4. Need a Backlight? If so, what color?
Step 5. Press the ‘buy it now’ button and wait for delivery. Maybe use this time to make a cup of coffee.
Prototype LCDs in stock:
All our character LCDs are in stock in Arizona, but we don’t offer gift wrapping for Christmas or birthdays. Sorry.
These two low-power LCD options are not as sexy (can I use that word here?) as a IPS, 1K Nit TFT, that lets you watch YouTube or check Facebook to see if your neighbor bought a gas or electric lawn mower. But, they do an excellent (bang-up) job at displaying letters and numbers and punctuation marks. If that is all you need, select one of these low-cost technologies and spend the rest of the money on one of those K-cup coffee makers
FocusLCDs.com LCDs made simple ®