We have a CFAH1602C-YYH-JP display hooked up in a tachometer circuit for a diesel engine and we can't get a good grip on how to hook up the backlight. Some posts on this forum have given me a start but I would like to be sure of what I'm doing so I don't burn something.
The Specification Data Sheets refer to pins 15,16,A & K when referring to the backlight. On the "Contour Drawing & Block Diagram" sheet on the contour dwg. there are 4 pins shown on the right side of the display. The top one is called "A" and the bottom on "K". Are these the A and K pins that service the backlight?
For the sake of my questions, I'll assume I'm right on that point at least.
On that same sheet toward the bottom they give 2 small block diagrams on the hookup of the backlight. Looking at the top one called "Drive from A, K" it appears all we need to do is pick up the 5V off the line that feeds pin 2 (VDD) and run a wire to the "A" pin on the opposite side with the right resistor to give us 4.2v to 4.6v on pin "A". Then run a wire from the "K" terminal to the ground side of the display, pin 1 (VSS). Am I right here.
The second method uses pin 15 for the 5V and 16 for ground. What puzzles me is the show 2 resistors. Anyone know why 2. Does the 4.2v to 4.6v spec. still apply in this method? Below this second diagram they have the following...
(Will never get Vee output from pin 15)
Duuhh....what is that telling me? Is it something I should consider in choosing a method to hookup the backlight?
Would one method be better than the other. We have bench tested the tach and it works like a champ but I hate to have to drive down the road at night with a mini Mag light stuck in my mouth to be able to read the tach.
Thanks for any help..
The Specification Data Sheets refer to pins 15,16,A & K when referring to the backlight. On the "Contour Drawing & Block Diagram" sheet on the contour dwg. there are 4 pins shown on the right side of the display. The top one is called "A" and the bottom on "K". Are these the A and K pins that service the backlight?
For the sake of my questions, I'll assume I'm right on that point at least.
On that same sheet toward the bottom they give 2 small block diagrams on the hookup of the backlight. Looking at the top one called "Drive from A, K" it appears all we need to do is pick up the 5V off the line that feeds pin 2 (VDD) and run a wire to the "A" pin on the opposite side with the right resistor to give us 4.2v to 4.6v on pin "A". Then run a wire from the "K" terminal to the ground side of the display, pin 1 (VSS). Am I right here.
The second method uses pin 15 for the 5V and 16 for ground. What puzzles me is the show 2 resistors. Anyone know why 2. Does the 4.2v to 4.6v spec. still apply in this method? Below this second diagram they have the following...
(Will never get Vee output from pin 15)
Duuhh....what is that telling me? Is it something I should consider in choosing a method to hookup the backlight?
Would one method be better than the other. We have bench tested the tach and it works like a champ but I hate to have to drive down the road at night with a mini Mag light stuck in my mouth to be able to read the tach.
Thanks for any help..
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