Báo Cáo Function generator controlled by pc

ABSTRACT
​

In electronic experiments, one needs an instrument that can generate various signal waveforms
(called waveform generator or signal generator or function generator). On the market, there are many
such instruments with a price range from medium to very high, depending on their specifications.
However, almost all of them cannot be controlled from PC, which is required by our laboratory
automation program. This project concentrates on designing and building a function generator
controlled by PC. Data concerning the signal such as waveform, frequency, amplitude, are output from
the PC and latched in the outer circuit. Afterwards, the PC is free to perform other tasks, and only
updates the data when necessary. We present two different designs having different characteristics.
One uses external static RAM (SRAM) and a Digital-to-Analog Converter (DAC) to generate the
waveforms. This method can produce arbitrary waveforms at low frequencies. The other uses the
waveform generator IC MAX038 (from Maxim) as the core of the system. We add some
complementary circuits to enable the control from PC. This latter design can attain output frequency
up to 20 MHz but cannot give arbitrary waveforms.