US Patent 7321328 Single bit DAC with tristate driver

A method for producing an analog output from a digital input is described. A digital pulse train is received having an average value which is proportional to a digital conversion value. The digital pulse train is driven at a periodic interval to produce a modulated tristate-gate output. The modulated tristate-gate output is averaged to produce an analog output. Optionally, the pulse train is also driven at an additional periodic interval having a duty cycle of more, or less, than less than 50%. The pulse train may also be driven steadily.