| 摘要 |
An analog voltage is used to directly alter the timebase of a pulse-width converter, thereby modifying a digitally-generated system output with an analog source. The input to the amplifier is coupled to a first counter (101) clocked by a voltage-controlled oscillator (VCO) (113), and second counter (104) driven by a fixed clock (114). The output of the first counter is ultimately delivered to a load device following appropriate filtering (107 and 111). The non-inverting input of a differential amplifier (112) is coupled to the load device, and the inverting input is coupled to the output of the second counter (104). The output of the differential amplifier forms the control voltage input to the VCO, which increases output frequency in response to increasing input voltage. An increase in frequency at the output of the VCO ultimately reduces the load voltage, thereby linearizing an otherwise digital amplifier with an analog signal. |
