jackjay ,I supose if you need to source current continously then the 23016 is the way to go. I have never relied on IC's to source current greater than a couple of mill's continously because of the high RDS ON of most P channel fet's. The PCA8575 16 bit and the PCF8574 8 bit i/o expanders DO source 25 mill's but only for a breif period of time to compensate for any loading on the pin. Therefore I usually select a component for it's ability to sink current rather than source it. If you look at the number of drivers IC's that sink current opposed to the number that source it's something like 10 to 1... I have never had a heat related problem in any of my designs in the last 30 years... I guess I'm just OLD SCHOOL....

Dave Purola,
N8NTA