A temperature-sensitive current source includes a first MOS transistor
having a source coupled to a first voltage; a second MOS transistor
having a source coupled to the first voltage, and a gate coupled to a
gate of the first MOS transistor, such that a current output at a drain
of the second MOS transistor mirrors a current passing across the first
MOS transistor; and a resistor coupled between the source and a drain of
the first MOS transistor in parallel, such that the current passing
across the first MOS transistor is substantially larger than a current
passing through the resistor, wherein the first and second MOS
transistors operate in a saturation mode, such that the output current at
the drain of the second MOS transistor is responsive to a change of
temperature.