Newhaven Display Forum

Newhaven Products => Character LCDs => Topic started by: Eashwar on July 05, 2019, 02:32:25 AM

Title: NHD-0216K3Z-FL-GBW-V3 : Backlight
Post by: Eashwar on July 05, 2019, 02:32:25 AM
Dear Sir/Madam,

I am using LCD character display P/N - NHD-0216K3Z-FL-GBW-V3. Few details are missing from the datasheet,
1. Is VLCD (contrast) 4.3V for backlight supply?
2. Where to connect backlight supply, connection for backlight are not mentioned in pinout table.
3. I am using SPI communication, I want to know Input high and low current (IIH and IIL).
4. I want to know the split current for LCD and Backlight.

Since it is battery operated application, it is important to know parameter mentioned in point 3 & 4.
Kindly provide the info ASAP.
Title: Re: NHD-0216K3Z-FL-GBW-V3 : Backlight
Post by: Alee_S on July 08, 2019, 12:08:50 PM
Hi Eashwar,

1) The VLCD is for the contrast voltage necessary for the LCD glass. This can be adjusted from your software as necessary.
2) The backlight and display power are tied together, and a 5V supply on the VDD pin will supply power to both the display and backlight. 
3) We don't spec our logic current values, as these parameters are voltage driven. So long as your voltage is above / below its rated levels, the display will register high and low as expected.
4) As mentioned before, the LCD power and backlight are tied together, and the display is spec'd to draw about 10-25 mA (18mA typical).

Display Datasheet: http://www.newhavendisplay.com/specs/NHD-0216K3Z-FL-GBW-V3.pdf (http://www.newhavendisplay.com/specs/NHD-0216K3Z-FL-GBW-V3.pdf)

Hope this helps!
Title: Re: NHD-0216K3Z-FL-GBW-V3 : Backlight
Post by: Eashwar on July 13, 2019, 09:54:45 AM
Dear Alee,

Thank you for your reply. Sorry for delay response did not mail notification, had to check through website.
Regarding point no. 2 and with reference to image you have attached in your previous reply,

VLCD (backlight) - 4.0V (min.) 4.3V (typ.) 4.6V(Max.)
VDD  - - 4.5V (min.) 5V (typ.) 5.5V(Max.)

It is confusing, since VLCD and VDD voltage does not match. I have designed two separate supply for VDD - 5V and VLCD - 4.3V.
Kindly confirm your reply once again, as you have told use same supply for both VLCD and VDD.

What is purpose of 'A' and 'K' (image attached) pin provided behind the display PCB.
Title: Re: NHD-0216K3Z-FL-GBW-V3 : Backlight
Post by: Alee_S on July 16, 2019, 02:14:48 PM
Hi Eashwar,

Plese note there is a difference between The VLCD and backlight voltage, as the VLCD is the voltage value needed for the LCD glass itself for optimal contrast, while the backlight power is driven by VDD, since the display power and backlight are generated from a single source for this display. VLCD is software configurable in this case.

A and K are pins responsible for the LED power, which can be powered from the VDD pin and is software configurable from the transistor and accompanying circuitry on the PCB.