A current compensation circuit for use with a current mirror circuit is
disclosed. The current mirror circuit has a current path defined by a
first programmable current mirror stage driving a first fanout current
mirror stage. The first programmable current mirror stage includes at
least one transistor with a channel length exhibiting a first channel
length modulation factor .lamda.1. The first fanout current mirror stage
connects to a supply voltage source. The current compensation circuit
comprises a supply voltage current mirror coupled to the supply voltage
source and has a current output coupled to the current path. The
compensation circuit further includes a second programmable current
mirror coupled in series to the supply voltage current mirror and
including at least one transistor with a channel length exhibiting a
channel length modulation factor .lamda.2. The second channel length
modulation factor .lamda.2 is larger than the first channel length
modulation factor .lamda.1. As a result, the first programmable current
mirror and the second programmable current mirror cooperate to maintain a
bias current through the first fanout current mirror stage substantially
independent of changes in the supply voltage.