HJ1602A Lcd Display for mini pulse 3

[satdaveuk]

Hi
Constructing the mini pulse 3 which is almost finished, its designed to use 5v lcd display.
I want to use a HJ1602AA display for less pwr consumption, runs on 3v 1-1.5ma.
it needs to be max 3.3v.
What is the best way of cutting 5v to 3v without drawing extra current, Would just a preset do?.
Im going to use backlight switched.

Thanks in advance

[Skippy]

A low-power linear regulator is the most obvious choice, and 3V or 3V3 should be an easily available voltage. LP2950-series springs to mind, if you can manage SMD, there's plenty of them.

[Comp]

Or, even simpler, just put 3 basic silicon diodes in series, 0.6 volt drop across each, gives you 5V minus 1.8V diode drop, 3.2V.

Cheap, easy, and next to no power loss.

Cheers, Fred

[6666]

If you only need 100ma maximum, you can use the smaller LM317L.
or search for Shunt Regulator

[Skippy]

Rather inefficient for 1.5 mA output, though - the LP2950 series will have a ground current of 100 microAmps ath these low output currents. Better still would be Torex XC6206 series, I've used these before, very impressive, full CMOS, they take less than 1 microAmp quiescent, but SMD package only.

[satdaveuk]

Thanks for the feed back Skippys idea is a good one but dont really want to mess with smd on this project, 6666 your idea would work but over the top and would loose alot of current im trying to save by using this low voltage lcd. Comp your 3 diode in4007 should do the trick just worried if a diode goes s/c then up goes the voltage and bumps the lcd out.
Would it be ok to do the 3 diode together with a 3.5 zener to deck just incase, or am i worrying about nothing and should just go ahead with the 3.

Regards

[Comp]

Thanks for the feed back Skippys idea is a good one but dont really want to mess with smd on this project, 6666 your idea would work but over the top and would loose alot of current im trying to save by using this low voltage lcd. Comp your 3 diode in4007 should do the trick just worried if a diode goes s/c then up goes the voltage and bumps the lcd out.
Would it be ok to do the 3 diode together with a 3.5 zener to deck just incase, or am i worrying about nothing and should just go ahead with the 3.

Regards

Nah, go for it!!!At the current levels drawn, I reckon there is more chance of you winning the Lottery, than one of them going s/c!!! Its a little trick I use now & then when I want to loose a volt or two,... and its never let me down!!!!! I have some Cmos, 3.3V max oscillator modules running at 106 Megs, and I did the same with them, they run at about 25ma if I remember correctly, (I was building my own wireless headphones!!!) and they run fine like this.......(& I'm only using IN1418's, I think.......)

Cheers, Fred

[satdaveuk]

Ok thanks for the advise will do.
Soon as the project is up and running, will do some posts on it.

All the best