Patent ID: 7057446
Filing Date: 2006-06-06
Classification: G05F

Abstract:
1. A reference voltage generating circuit, comprising: a distributing unit which generates via an output terminal a reference voltage, which has a lower voltage level than that of an external power supply voltage and varies according to an operating mode, in response to the external power supply voltage; a clamping control unit connected between the output terminal and a ground voltage, the clamping control unit for clamping a voltage level of the reference voltage at a constant level in response to a control voltage having a voltage level which is lower than that of the reference voltage; and a control unit connected to the distributing unit for increasing or decreasing a voltage level of the reference voltage in response to first and second operating mode signals by controlling the operating mode of the distributing unit, wherein: in a low operating frequency range, the first and second operating mode signals are at a first level; in a high operating frequency range, the first and second operating mode signals are at a second level; and in an intermediate frequency range, one of the first and second operating mode signals is at the first level and the other is at the second level.