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I'm building a circuit using the HDMI/DVI decoder TFP401A. I'm only running it in single pixel mode so I only need to worry about 24 output lines, instead of 48. My goal is to take the 24 lines and turn them into 3 output lines (one for red, green and blue respectively). Originally, in my schematic, I had used an ATMEGA162-16AU but I realised I'd need at least 3 analog outputs, which I believe it doesn't have. But that got me thinking that actually I was just using an MCU as a DAC, which seemed kind of pointless.
I've been digging into DACs and I really can't find anything that suits my need. A lot of what I found requires either a negative voltage, a voltage reference higher than Vcc or both. I've only got access to 5V and 3.3V so I can't really use a negative voltage, or Vref that is double the Vcc. This already narrows down the selections quite a lot. There were a couple that I found, including the PCF8591 and AD7524JRZ. These do have stock (though little) in the JLCPCB part library, however, they are fairly pricy, where 3 of them would set me back at minimum 15 pounds. The other DACs I found do not have any stock in JLCPB, and if they don't have stock there, I find there often isn't stock elsewhere either. If there is, it's always much, much more expensive (for example, the AD558 which is only $5.6 on JLCPCB [out of stock], but £25 on Mouser, per chip).
My other solution is to just go back to using an MCU. Most likely I'd use Atmel's ATMega series since they're pretty easy to program, and chances are there'll be a chip that has enough pins, both analog and digital (like the ATmega2560), but stock would still be an issue I would guess.
I have thought about just a basic resistor network based DAC, but often with solutions like that, they come with big downsides (noise not being one here - I'm not too worried if it's a little noisy).
Should I use a R-2R DAC? Is there any other recommended DACs? Is an MCU a better choice? Any help would be appreciated!
I've been digging into DACs and I really can't find anything that suits my need. A lot of what I found requires either a negative voltage, a voltage reference higher than Vcc or both. I've only got access to 5V and 3.3V so I can't really use a negative voltage, or Vref that is double the Vcc. This already narrows down the selections quite a lot. There were a couple that I found, including the PCF8591 and AD7524JRZ. These do have stock (though little) in the JLCPCB part library, however, they are fairly pricy, where 3 of them would set me back at minimum 15 pounds. The other DACs I found do not have any stock in JLCPB, and if they don't have stock there, I find there often isn't stock elsewhere either. If there is, it's always much, much more expensive (for example, the AD558 which is only $5.6 on JLCPCB [out of stock], but £25 on Mouser, per chip).
My other solution is to just go back to using an MCU. Most likely I'd use Atmel's ATMega series since they're pretty easy to program, and chances are there'll be a chip that has enough pins, both analog and digital (like the ATmega2560), but stock would still be an issue I would guess.
I have thought about just a basic resistor network based DAC, but often with solutions like that, they come with big downsides (noise not being one here - I'm not too worried if it's a little noisy).
Should I use a R-2R DAC? Is there any other recommended DACs? Is an MCU a better choice? Any help would be appreciated!
