Whether or not its buck, increase, or buck/increase, inside or exterior swap, milliamps or tens of amps, a literal cornucopia of programmable output switching regulator/converter chips are commercially out there. Whereas the required exterior Ls and Cs (after all) range wildly from topology to topology and chip to chip, (virtually) all use precisely the identical primary two-resistor community for output voltage programming proven in Determine 1. Its instance buck kind regulator was picked roughly arbitrarily, so please ignore the L and Cs and simply give attention to R1, R2, and (later) R3.
Determine 1 The (virtually) common regulator output programming community the place Vout = Vsense(R1/R2 + 1) = 0.8v*(11.5 + 1) = 10v.
Wow the engineering world together with your distinctive design: Design Concepts Submission Information
For causes identified solely to gurus of the mystic and marvelous monolithic realm, the precision Vsense suggestions node voltage varies from kind to kind over a roughly 3:1 vary from 0.50v to 1.5v. Really useful values for R1 range too.
The purpose is the topology doesn’t range. All (or at the least most) conform faithfully to Determine 1. This shocking uniformity turns into very helpful in case your software requires DAC management of the output voltage. See Determine 2 for the way this may be carried out with a constructive polarity DAC and only one added resistor: R3.
Determine 2 Regulator output programming with a DAC and the KISS1 community the place Vout = (Vc)*(R1/R2) = (2.5 to 0v) 4 = 0 to 10v.
Given cheap decisions for the DAC (e.g., 2.5v), numbers for R1 and Vsense from the regulator chip datasheet, and Vomax out of your software necessities, right here’s the KISS1 arithmetic:
- R2 = R1 Vcmax/Vomax
- R3 = R1/(Vomax/Vsense – R1/R2 – 1)
And, within the grand custom of the KISS1 precept, that’s it. Okay, okay. Besides perhaps for a few (minor?) caveats. For instance:
- Expression 2 above, and subsequently the mandatory worth for R3, should shake out constructive. I can’t consider a sensible case the place it wouldn’t, however there’s most likely some perverse permutation of parameters on the market the place it gained’t, and implementing unfavorable resistors isn’t notably easy.
- The relation between Vout and Vc is inverse. So, the digital model of Vc should be 1’s complemented (a completely KISS-bit of software program arithmetic to flip all of the bits, so 0s turn out to be 1s, and 1s turn out to be 0s) earlier than being written to the DAC register.
- Vin should be enough for the chosen chip to generate the chosen Vomax when Vc = 0. Duh.
So perhaps it’s probably not completely KISS1, simply principally.
1 Well-known KISS precept: Is a footnote actually essential?
Stephen Woodward’s relationship with EDN’s DI column goes again fairly a good distance. Over 100 submissions have been accepted since his first contribution again in 1974.
Associated Content material
- PWM energy DAC incorporates an LM317
- Parsing PWM (DAC) efficiency: Half 2—Rail-to-rail outputs
- Precision DC motor pace management through pot or DAC
- Designing with a DAC: Accept one of the best
googletag.cmd.push(perform() { googletag.show(‘div-gpt-ad-native’); });
–>
The submit Add one resistor to permit DAC management of switching regulator output appeared first on EDN.
👇Observe extra 👇
👉 bdphone.com
👉 ultractivation.com
👉 trainingreferral.com
👉 shaplafood.com
👉 bangladeshi.assist
👉 www.forexdhaka.com
👉 uncommunication.com
👉 ultra-sim.com
👉 forexdhaka.com
👉 ultrafxfund.com
👉 bdphoneonline.com
👉 dailyadvice.us
