OK Folks,
After a rather long absense, I thought I update what I've been doing. The attached info produces a nice sine / square /triangle generator based on the AD9834 chip.
Function Generator Specs:
1 Hz to 1MHz in steps. (56 steps to be exact)
4 separate outputs:
- main output +3dBV (1.4VRMS), 100 ohms, about 0.025% dist sine wav
- lo dist 1kHz. +3dBV, 1000 ohms, about 0.008% dist
- Inverse RIAA output, 26dB below main output@1kHz, 50 ohms
- 5V P-P constant level square wave for trigger purposes
3 different sweeps available
- Fast 1Hz to 1MHz
- Slow 1Hz to 1MHz
- Slow 20Hz to 20kHz
Indicators: 48 LEDs indicate frequency(43) and function(5)
Push button / functions
- Up, Down (fixed frequencies)
- GOTO 1kHz
- GOTO 20Hz
- GOTO 20kHz
- toggle: sine/triangle/square
- toggle: fixed/sweep1/sweep2/sweep3
Powered from 4 AA batteries, current consumption about 20mA.
Output Level adjustment
- variable +3 to -10dBV
- stepped 0, -10, -20, -30, -40, -50, -60 dB
Active Devices (sorry, no tubes)
- 1 Analog Devices AD9834
- 1 Microchip PIC processor 16F59
- 2 KM4270 dual 10MHz op amps
- 1 KM4120 75MHz op amp
Size: About the size of a hand held Fluke 83 DMM
I have attached picture of the thing next to a Fluke 83 for comparison.
I have also attached .GIF schematics and a ZIP file containing:
- PDF schematic pages
- the picture
- PIC source code
- PIC object code (programming file)
This is a cute little unit, but reasonably intricate to build, but not too expensive.
Since it's software controlled, different / additional functions are certainly possible.
Steve
A Function Generator Project - not for the feint of heart
Moderator: sbench
A Function Generator Project - not for the feint of heart
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