The voltage source and current source circuits including an amplifier, a
first current mirror circuit, a first PMOS transistor, a second current
mirror circuit and a NMOS transistor are provided. The amplifier has a
positive input terminal and a negative input terminal coupled to the
source terminal of the NMOS transistor. The first current mirror circuit
is coupled to a reference current and duplicates the reference current to
the source terminal of the first PMOS transistor. The first PMOS
transistor has a drain terminal, a gate terminal and a source terminal.
The drain terminal of the NMOS transistor is coupled to the third current
terminal, and the gate terminal of the NMOS transistor is coupled to the
source terminal of the first PMOS transistor. The second current mirror
circuit duplicates the current from the third current terminal.