Digital to analog conversion apparatus

• US 3,281,832 A
• Filed: 09/23/1964
• Issued: 10/25/1966
• Est. Priority Date: 09/23/1964
• Status: Expired due to Term

• Current Assignee: Robert J. Schwartz
• Original Assignee: Robert J. Schwartz
• Inventors: Schwartz, Robert J.
• Application Number:
  US04/398,576
• Time in Patent Office: 762 Days
• US Class Current: 341/153
• CPC Class Codes: H03M 1/00 Analogue/digital conversion; Digital/analogue conversion conversion of analogue values to or from differential modulation H03M3/00
• CPC Class Codes: H03M 1/48 Servo-type converters

Claims

1. APPARATUS FOR CONVERTING DIGITAL DATA INTO ANALOG FORM COMPRISING, A PLURALITY OF RESISTORS HAVING RESPECTIVE VALUES RELATED IN ACCORDANCE WITH THE WEIGHTS OF THE INDIVIDUAL BITS OF THE DIGITAL WORD TO BE APPLIED THERETO, AN OUTPUT IMPEDANCE ELEMENT, RESPECTIVE SWITCH MEANS SELECTIVELY COUPLING ONE END OF EACH OF SAID RESISTORS TO ONE TERMINAL OF SAID OUTPUT IMPEDANCE ELEMENT, THE OTHER TERMINAL THEREOF BEING CONNECTED TO A SOURCE OF REFERENCE POTENTIAL, A VARIABLE POTENTIAL SOURCE COUPLED IN COMMON TO THE OTHER ENDS OF SAID RESISTORS, AND MEANS COUPLED BETWEEN SAID OUTPUT IMPEDANCE ELEMENT AND SAID VARIABLE POTTENTIAL SOURCE TO ADJUST SAID SOURCE IN RESPONSE TO A CHANGE IN POTENTIAL ACROSS SAID OUTPUT IMPEDANCE ELEMENT TO MAINTAIN A CONSTANT POTENTIAL ACROSS SAID RESISTORS.