Patent ID: 6498405
Filing Date: 2002-12-24
Classification: G05F

Abstract:
A supply reference voltage circuit, comprising:a supply voltage node; a supply reference voltage node; a blocking diode coupled between the supply voltage node and the supply reference voltage node; an output node; and a circuit coupled to the output node, the supply voltage node and the supply reference voltage node and operable to prevent current flow through an output device coupled to the output node in response to sensing a low voltage level at the supply voltage node and a non-zero voltage at the output node, the circuit further operable to connect the supply reference voltage node to the supply voltage node in response to the voltage at the output node being a threshold voltage above the voltage at the supply voltage node, and the circuit further operable to connect the supply reference voltage node to the supply voltage node and bypass the blocking diode in response to sensing a high voltage level at the supply voltage node.