A tribute to analogue design
master, Bob Widlar
The Fairchild μA723 voltage regulator is not at first sight a particularly exciting integrated circuit. Designed by the legendary Bob Widlar and released in 1967, it should have followed the majority of its contemporaries and faded from supplier catalogues and parts lists during the 1970s as it was superseded by more capable devices. Instead it has persisted, and five decades later it can still be found in the product lists of several semiconductor companies.
This project is a tribute to the chip's dessigner and its legacy.
Assembly and usage
The project includes the following components
- x1 μA723, TI UA723CDR
- x1 NPN BJT TO-220, Fairchild BD239BTU
- x5 470Ω resistor 250mW, Multicomp MCF 0.25W 470
- x5 4.3KΩ resistor 500mW, RS PRO739-8809
- x5 1.5KΩ resistor 500mW, RS PRO739-8767
- x3 10KΩ resistor 250mW, Multicomp MCF 0.25W 10K
- x1 10Ω resistor 600mW, Multicomp MCMF006FF100JA50
- x1 3Ω resistor 600mW, Vishay MBB02070C3008FCT00
- x1 10KΩ trimmer, Bourns 3306W-1-103
- x2 100pF ceramic capacitor, Suntan TS15001H101KSBSA0R
- x2 470pF ceramic capacitor, Suntan TS15001H471KSBPA0R
- x1 PCB
Jenny List has written a comprehensive guide to Widlar's μA723 in context of this project. Please follow her guide for the interesting things that this chip and board can achieve.
Widlar is an open source design, as is most of our work. You can find the design files for the hardware and packaging at our GitHub repository. You can edit the design files using our own PCB design open source software, PCBmodE.
This PCBs were manufactured by Eurocircuits.
Finally, community contributions for this project are on our community site.