name:         PCF8591
function:     8-bit A/D and D/A converter
package:      DIP16,16
manufacturer: Philips

     +--()--+
ain0 | 1  16| Vdd
ain1 | 2  15| aout
ain2 | 3  14| Vref
ain3 | 4  13| agnd
  a0 | 5  12| ext
  a1 | 6  11| osc
  a2 | 7  10| scl
 Vss | 8   9| sda
     +------+


This pinout came from the Chipdir:
http://www.chipdir.org/