Is there any modern MC34063 part? - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 20, 2018, 04:03:32 pm
content: Hi,I wanted to know if there are some newer parts with the Mhz working range, higher voltages and current or internal MOSFETS instead of BJT's. Do we have any option?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 20, 2018, 05:15:10 pm
content: Astonishingly, hysteretic controllers -- terrible as they are -- do still exist.Fortunately, there are zillions of better alternatives!https://imgur.com/a/M1S0DbITim

author: Benta
author_rank: Super Contributor
timestamp: November 20, 2018, 05:16:48 pm
content: NCP3063

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 21, 2018, 05:56:08 am
content: QuoteThanks, I know there are better ones, But I wanted to know if there are better ones that could be configured for, Buck,boost and inverting apps.QuoteThanks, But it's some how still the same as MC34063 a little bit higher frequency.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 21, 2018, 09:22:04 am
content: I mean, if you want modern bad controls, TPS40200 and LM5085 for example exist for some reason. Looks like they feign current... protection, at least, but that's nowhere near as good as actual currentcontrol.TPS40211 is much better, more akin to a UC3843, which is, you know, actually current controlled.It's not gonna be directly buck compatible, no. IMHO, it would be foolish to wish for such in a single low-pin IC (I'd dare use the '34063 as a cautionary example of why this is so). Need buck? Just tack on a bootstrap gate driver. Boom. Done.Regulators are also available in a spectrum of voltage ratings, currents, frequencies and topologies. You don'twanta universal controller or regulator -- indeed, the market has spoken, diversity carries the day here!Tim

author: David Hess
author_rank: Super Contributor
timestamp: November 21, 2018, 03:04:47 pm
content: Quote from: T3sl4co1l on November 20, 2018, 05:15:10 pmHysteretic controllers are not all bad; they do not require frequency compensation and this lack makes them very fast responding.QuoteThe same people who have problems getting the MC34063 (and 78S40) to work have problems applying any switching regulator to work.The LT3470 is a modern part. The CS51031/CS51033 is more comparable to the MC34063 but requires an external power transistor.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 21, 2018, 04:22:01 pm
content: Quote from: T3sl4co1l on November 21, 2018, 09:22:04 amI fail to see how LM5085 doesn't have an actual current control. It looks like they sense voltage drop in a shunt resistor, or Rds(on), and use a comparator on this to trig an off-time counter. For me, this is the very definition of an actual current control (or, to be more precise, one way to implement it), and this should guarantee the inductor current within a well defined band, and do it without subharmonic oscillation like peak current mode controllers; and do it without overshoot in all conditions, (compared to too slow average current mode controllers where the current signal controls the PWM block and may require compensation). What I'm missing here, what's the problem?

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 22, 2018, 11:55:35 am
content: QuoteThanks for the tips.