Hello,
I wanted to select some parts for use with my FPGA (not really experienced in the market, only digital audio) and was looking at the R2R resistors/ R2R DAC chips. Since I got the headroom internaly to do 32 bits and various interpolations and oversamplings, I was looking at non oversampled and non amplified chips sporting R2R ladders. So I can keep the option open to chain two chips together for instance to make 32 bits. Seeing the resistors will set me back about 100 Euros excluding the driver circuit.. I was wondering if anyone knows of some parts that I have to look into?I know I can just drop the lower 8bits, and all that. Which is definately true, so 3x8 is also great. In general chuffed about these parts to look into.
All the best!
I wanted to select some parts for use with my FPGA (not really experienced in the market, only digital audio) and was looking at the R2R resistors/ R2R DAC chips. Since I got the headroom internaly to do 32 bits and various interpolations and oversamplings, I was looking at non oversampled and non amplified chips sporting R2R ladders. So I can keep the option open to chain two chips together for instance to make 32 bits. Seeing the resistors will set me back about 100 Euros excluding the driver circuit.. I was wondering if anyone knows of some parts that I have to look into?I know I can just drop the lower 8bits, and all that. Which is definately true, so 3x8 is also great. In general chuffed about these parts to look into.
All the best!
Just an FYI, but you can't just glue two N bit ladders together to get a 2N bit ladder. The problem is that the resistors in the ladder have to be as accurate as 1 part in 2^(N+1) where N is the number of bits in the _entire_ ladder. For example, to make an 8 bit ladder, the resistors should be accurate to 1 part in 512, or 0.2%, but to make a 16 bit ladder, the resistors need to be accurate to 1 part in 131072. So, with a good 8 bit ladder, it has nowhere near the accuracy needed for use as the 8 most significant bits of a 16 bit ladder.
True that, I was actually hinting at it. Seeing it is for a musical instrument I think theoretical accuracy is overrated, since they all fall within multiples of themselves.
Also you can sort of just can chain them toghether,
Not to be ignoring the boundaries of physics but I'd like to find brands/vendors of R2R ladders. I can't seem to stumble upon the parts I see passing by, like the 8 bit sort of caterpillar looking through hole types. Or "preferably unpumped" PCM63 alike IC's? Also I noticed the Vishay resistors, but maybe similar through hole/SMD resistors at a nice pricepoint..
Just for finding the right parts for the job, and the breadboard..
Also you can sort of just can chain them toghether,
Not to be ignoring the boundaries of physics but I'd like to find brands/vendors of R2R ladders. I can't seem to stumble upon the parts I see passing by, like the 8 bit sort of caterpillar looking through hole types. Or "preferably unpumped" PCM63 alike IC's? Also I noticed the Vishay resistors, but maybe similar through hole/SMD resistors at a nice pricepoint..
Just for finding the right parts for the job, and the breadboard..
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