×

Digital to analog signal converter

  • US 4,931,795 A
  • Filed: 08/09/1989
  • Issued: 06/05/1990
  • Est. Priority Date: 08/09/1989
  • Status: Expired due to Term
First Claim
Patent Images

1. A D to A converter stage comprising:

  • a current mirror including an input transistor and an output transistor connected to a supply voltage, the input transistor also being connected to a reference current source and the output transistor being connected to an output for the current mirror;

    a current adjusting transistor in parallel with each of the input and output transistors for adjusting the output current of the current mirror as a function of the operating states of the current adjusting transistors;

    digital signal activated switch means for selectively controlling operation of each current adjusting transistor; and

    circuit means for regulating drain voltages on the input and output transistors whereby the values of currents flowing in the input and output transistors and hence the value of the output current is a direct function of the relative geometric sizes of the input, output and current adjusting transistors.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×