The ZN449E is an 8 bit a/d. Therefore, its resolution is equal to the Vfs/256, where Vfs is the maximum full scale input. The Vfs value can be adjusted to any value above 2.5 V by the use of external resistors. For example, if you set Vfs to 10V, then the resolution would be 10/256 = .0390625 V. The output values go like this:
~ Vin Code
~ 0 00000000
~ .0390625 00000001 (1 LSB worth of voltage)
~ .078125 00000010 (2 LSBs worth of voltage)
~ .
~ .
~ 5.0 10000000 (1/2 full scale)
~ .
~ .
~ 9.84375 11111110 (Full Scale minus 2 LSBs worth of voltage)
~ 9.9609375 11111111 (Full Scale minus 1 LSB worth of voltage)
.
The ZN449E can be set up (using external resistors) as a bipolar converter that can convert negative and positive voltages.
You can get a data sheet at h**p://products.zarlink.com/assets/zn448.pdf. The data sheet gives more detail on setting up the full scale voltage, setting up for bipolar operation, etc. Note that this product is obsolete.