Patent ID: 7808308

Claim:
A voltage generating apparatus, comprising: a first N-type transistor, comprising a gate, a first drain/source, and a second drain/source, the first drain/source being coupled to a first voltage, the second drain/source generating a first output voltage, and the gate being coupled to a second voltage; an enhancement metal oxide semiconductor field effect transistor (MOSFET), comprising a gate, a first drain/source, and a second drain/source, the first drain/source being coupled to the second drain/source of the first N-type transistor, and the second drain/source and the gate being coupled to the second voltage, wherein the first N-type transistor is a depletion MOSFET; and M second N-type transistors, connected in series in a path of coupling the first drain/source of the first N-type transistor to the first voltage, each of the second N-type transistors comprising a gate, a first drain/source, and a second drain/source, wherein M is a positive integer; wherein the first drain/source of the 1st second N-type transistor is coupled to the first voltage, the second drain/source of the Mth second N-type transistor is coupled to the first drain/source of the first N-type transistor, and the gate of the Mth second N-type transistor is coupled to the second drain/source of the first N-type transistor, and furthermore, the second drain/source of the ith second N-type transistor is coupled to the first drain/source of the i+1th second N-type transistor, the gate of the ith second N-type transistor is coupled to the second drain/source of the i+1th second N-type transistor, 1≦i<M, and i is an integer.