| US 7,482,961 B1 | ||
| Digital feedthrough cancellation | ||
| Dan Baker, Medina, Ohio (US); and Michael D. Rayman, Akron, Ohio (US) | ||
| Assigned to Keithley Instruments, Inc., Cleveland, Ohio (US) | ||
| Filed on Jun. 08, 2007, as Appl. No. 11/760,047. | ||
| Int. Cl. H03M 1/66 (2006.01) | ||
| U.S. Cl. 341—144 [341/145] | 3 Claims |
| 1. A method for operating a DAC to minimize digital feedthrough, said DAC having a clock input and a data input, said method
comprising:
inputting a clock signal to said DAC clock input, said clock signal having a periodic series of trigger events, wherein input
data must be present for a time window between a setup time before a trigger event and a hold time after said trigger event;
generating an input data stream, said input data stream having data that is present for said time window;
altering said input data stream into a cancellation data stream wherein said data presence is maintained but pseudo-data outside
of said time window is added; and
applying said cancellation data stream to said DAC data input resulting in an analog signal output.
|