Patents Represented by Attorney Davis Wrright Tremaine LLP
  • Patent number: 7903014
    Abstract: A circuit and corresponding method are presented for generating an analog voltage from a digital input value is presented. An digital to analog conversion circuit, which is connected between a node and ground, receives an N-bit digital input value and generate from it a corresponding analog voltage. The node receives an input voltage provided by an op-amp connected to receive a reference voltage. The circuit also includes a variable resistance connected between the first node and ground in parallel with the digital to analog conversion circuit. The variable resistance is also connected to receive one or more of the digital input value and the value of the variable resistance is dependent upon the digital input values such that the combined current drawn from the first node by the variable resistance and the digital to analog conversion circuit is essentially constant during operation.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: March 8, 2011
    Assignee: SanDisk Corporation
    Inventor: Feng Pan