SuperSVGA
Well-known member
You still have it? On mine it looks like the 1.2V reference varies based on battery voltage, which definitely should not happen. I replaced it which gave it a small boost, but it's still not stable.I ran into a backlit portable that had this same regulation problem. Never did figure that one out when all the traces were good.
Right now I'm looking at op-amp output A which I haven't traced out but I'm guessing is a negative feedback setup. My guess there's a voltage or current issue somewhere there that's causing the zener reference to drop when the battery voltage is lower.