Square-Law Amplifier

July 2020
StatusBuilt
Circuit familyHegglun square-law / HEXFET
Photographs26 full-size gallery images
Downloads5 local design and reference files

Project Notes

An adaptation of Ian Hegglun's square-law design using an op-amp input and vertical MOSFET outputs. The archive follows simulation, PCB and hardware work, compensation experiments, cooling and analyzer tests.

diyAudio discussion

Photo Gallery

20200718 121408 HDR
1. 20200718 121408 HDR 		20200718 121540 HDR
2. 20200718 121540 HDR 		20200718 121819 HDR
3. 20200718 121819 HDR 		20200719 114704
4. 20200719 114704
20200719 114709
5. 20200719 114709 		20200722 095955 HDR
6. 20200722 095955 HDR 		20200725 163144 HDR
7. 20200725 163144 HDR 		20200726 093150
8. 20200726 093150
bias testing22
9. bias testing22 		fft 35v
10. fft 35v 		hegglun hexfets.42v.ccs
11. hegglun hexfets.42v.ccs 		hg pcb1
12. hg pcb1
sim 1khz thd
13. sim 1khz thd 		square law1
14. square law1 		20200725 122210 HDR
15. 20200725 122210 HDR 		20200725 122135 HDR
16. 20200725 122135 HDR
20200725 122130 HDR
17. 20200725 122130 HDR 		20200725 122128 HDR
18. 20200725 122128 HDR 		20200725 122117 HDR
19. 20200725 122117 HDR 		20200725 122116 HDR
20. 20200725 122116 HDR
20200725 122103 HDR
21. 20200725 122103 HDR 		20200725 122100 HDR
22. 20200725 122100 HDR 		20200725 122056 HDR
23. 20200725 122056 HDR 		20200725 122054 HDR
24. 20200725 122054 HDR
20200726 091654
25. 20200726 091654 		20200726 091635
26. 20200726 091635 		   

Design Files and Documents

Documents and notes

FileSize
doc\EW-WW_Hegglun_Square-Law-Rules-revised_Sep-1995.pdf 695 KB
doc\EW-WW-CI_Hegglun_Fast-Power-Amplifier-for-audio_Mar-1995.pdf 122 KB
doc\positive-feedback.com-The Square and Exponential Laws.pdf 934 KB
readme.txt 2 KB

LTspice simulations

FileSize
hegglun_hexfets.42v.ccs.asc 12 KB
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