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https://www.dropbox.com/s/0h88ikjnbxcisl3/CUI_PXO_DC-DC.jpg?raw=1 https://www.mouser.com/ProductDetail/CUI-Inc/PXO7805-500-S?qs=Y0Uzf4wQF3l34%252B7eogTBxw%3D%3D This is the 5 volt out version but there are others. It can also convert plus to minus. I can't buy the parts for three times that price.

I have a 48 volt power supply and I want to drive a lot of relays and uPs and FPGAs and stuff, so I figured I'd knock it down to 12...

I have a 48 volt power supply and I want to drive a lot of relays and uPs and FPGAs and stuff, so I figured I'd knock it down to 12 volts first. We have LM2567HV-ADJ in stock, a 52 KHz Simple Switcher probably designed by druids during the last ice age. Figured I'd breadboard the reg just for fun. A boy gets tired of typing all day. https://www.dropbox.com/sh/ajtqs7c1nswfhey/AABi7r0gchlj...

I have +12 from a wart, and I need -1.2 and -5 to power some analog stuff and ECL. I can do...

I have +12 from a wart, and I need -1.2 and -5 to power some analog stuff and ECL. I can do this https://www.dropbox.com/s/3b0iff93k1k2ct6/TPS_Inv_1.JPG?raw=1 Problem is, I don't want to run Tina and there is no LT Spice model. It may go into burp mode at my modest load currents, so I could get a lot of output ripple. It might want some lead compensation too. I guess I should br...

As I design yet another little switcher, I notice it's getting more and more tempting to swap ye olde MOS FET for a shiny new...

As I design yet another little switcher, I notice it's getting more and more tempting to swap ye olde MOS FET for a shiny new GaN-speck. Electrically superior in almost every respect, the GaN FETs' drawbacks are thermal (not a problem in this case), and their tee-nine-sie .9x.9mm bare-chip packages. e.g. T.I. CSD19831Q3: 100V, Rds(on)=50mohm, Cin=350pF, Coss=70pF, Crss=13pF EPC EPC...

Before I got too far down the rabbit hole... sanity check time :-) tl;dr: I want to run servos off nonisolated 160 vdc background: I'm...

Before I got too far down the rabbit hole... sanity check time :-) tl;dr: I want to run servos off nonisolated 160 vdc background: I'm updating this: http://www.delorie.com/electronics/bldc/ So the old driver used an external motor power supply (I had a 80VDC linear but it's big and used hard to get parts) and a separate external 15V driver supply (closed box switcher). The servos I'...

TPS54302 is a wonderful little synchronous switcher chip. 3 amp switcher in SOT-23, under a dollar. It does radical spread-spectrum pwm but...

TPS54302 is a wonderful little synchronous switcher chip. 3 amp switcher in SOT-23, under a dollar. It does radical spread-spectrum pwm but the dc output is quiet. We're designing a small box that contains about 400 power relays. To reduce coil power, we'll run the relay coils at 12 volts and bump them up to 24 briefly when we change setups. One issue is whether the switcher can switch 2...

Hi LM2676S-ADJ lead-free are hard to get now. Has anyone tried substituting LM2670 series with success? I am looking at the datasheets trying...

Hi LM2676S-ADJ lead-free are hard to get now. Has anyone tried substituting LM2670 series with success? I am looking at the datasheets trying to find a trap. Not using sync. Need a direct substitute without any changes to surrounding passive parts if possible. Geoff

I used to love the LTM8078 dual switcher module. But it rings hard at around 400 MHz at every switch transition. This is called a...

I used to love the LTM8078 dual switcher module. But it rings hard at around 400 MHz at every switch transition. This is called a "Silent Switcher!" I breadboarded a 24-to-5 volt switcher with an ancient bipolar LM2576. It switches at 50 KHz. And at every switching edge, it rings at about 40 MHz. We tried all sorts of stuff on both switchers. Nothing so far has any effect on the ringing...

I really like the TPS5 family of tiny little switchers, but their Spice models are, to be kind, absurd garbage. The first switcher on our board...

I really like the TPS5 family of tiny little switchers, but their Spice models are, to be kind, absurd garbage. The first switcher on our board simulates input power of 12 volts * 9 tera-amps. We're well along on pcb layout of a new delay generator, but I really want more confidence that everything will work first pass. So in parallel we're prototyping the switchers. https://www.dropbox....

I would like to build an off-line switcher based on the TinySwitch4 family. It implies f=132kHz. Then, VOUT=15V@0.5A....

I would like to build an off-line switcher based on the TinySwitch4 family. It implies f=132kHz. Then, VOUT=15V@0.5A. V_IN_MIN=120V, V_IN_MAX=374V (85-265VAC). I typed these values into the Schmidt's calculator to get a rough estimate: http://schmidt-walter-schaltnetzteile.de/smps_e/spw_smps_e.html L_PRI=7.36mH. OK, so now use PI Expert Online, provided by the manufacturer: Automatic ...

https://www.dropbox.com/scl/fo/cx2tgk4xexj134kck54js/h?rlkey=qrp95nd26g5zy2bjqce1k5pfa&dl=0 Diodes Inc AP63300. This will switch +48 down to...

https://www.dropbox.com/scl/fo/cx2tgk4xexj134kck54js/h?rlkey=qrp95nd26g5zy2bjqce1k5pfa&dl=0 Diodes Inc AP63300. This will switch +48 down to 5/12/24 or whatever. I tested it because sometimes synchronous switchers make horrendous noise spikes, but this looks pretty good. The trick seems to be to tweak the doping so the substrate diode isn't an SRD.

I've got a 24V incoming supply, and a need for a number of supplies (+12, +5, -5, and +3.3). The +/- 5V supplies are for a bit of analog...

I've got a 24V incoming supply, and a need for a number of supplies (+12, +5, -5, and +3.3). The +/- 5V supplies are for a bit of analog circuitry on a largely digital board, so they have low current requirements. My plan for the +5V supply is to just hang a 78xx05 off the +12V. +12V and +3.3V are going to come from switchers off of +24V. Anyone have any suggestions for a clever way ...

So, I'm goofing off playing with small switchers. (Well, not exactly goofing off, but there are somewhat more pressing tasks waiting....) As...

So, I'm goofing off playing with small switchers. (Well, not exactly goofing off, but there are somewhat more pressing tasks waiting....) As I said in George's thread, "Opamp w/ Vsupply > 36V", I built a small half-bridge supply with positive and negative voltage doublers. I'm not that keen on it, because (a) it uses a fair number of parts for what it does, and (b) it has a nasty ins

TI has encrypted Pspice models for many of their parts, but I can't persuade LT Spice to run the switchers I want to use. Any thoughts...

TI has encrypted Pspice models for many of their parts, but I can't persuade LT Spice to run the switchers I want to use. Any thoughts on that? One of my guys says he can run their Cadence sim, but I'd prefer LT. Parts are TPS54302, TPS563300, TPS562208. I'd consider paying a consultant to get them to work in LT Spice. If sim is too much hassle, we'd solder.

We are using TPS54302 and TPS562208. I haven't been able to get their Pspice models to work in LT Spice. They throw goofy errors, or run...

We are using TPS54302 and TPS562208. I haven't been able to get their Pspice models to work in LT Spice. They throw goofy errors, or run but at fs speeds and make no useful progress. TI apparently has their own sim, Cadence maybe, that might run these parts. Does anyone know how to do that, run the TI models with the TI software? Or to get the Pspice models to run usefully in LT Spic...

The Tek power supply thread reminded me of these interesting old books, some of which are still an excellent...

The Tek power supply thread reminded me of these interesting old books, some of which are still an excellent read. https://www.davmar.org/concepts.html My fave is Bob Orwiler's Vertical Amplifiers Concepts, . (The Power Supply Circuits book is too old to be much use, though it does talk about switchers a bit.) Cheers

Diodes is lately a lot more than diodes. A similar case is Onsemi, a spinoff of Motorola that inherited the cheap gumdrop business but does a...

Diodes is lately a lot more than diodes. A similar case is Onsemi, a spinoff of Motorola that inherited the cheap gumdrop business but does a lot more now. Diodes has some dynamite new switchers, the AP66200 parts, that I'd like to use. Any experience with Diodes, as regards support and especially keeping parts in production? Any horror stories?

I have a sim that hangs up unless I use the alternate solver. Is there a directive I can put in my circuit to force that? Or is there only the...

I have a sim that hangs up unless I use the alternate solver. Is there a directive I can put in my circuit to force that? Or is there only the persistant setting in the tools/control panel menu? Good news: the latest update finally includes the LTM8078 switcher! I'm teaching it how to convert +24 into -5 and -2.5. -- John Larkin Highland Technology, Inc Science teache...

I'm simulating a flyback switcher and noticed that any K < 1 in the transformer radically slows down the sim, which is annoyingly...

I'm simulating a flyback switcher and noticed that any K < 1 in the transformer radically slows down the sim, which is annoyingly slow already... 90 seconds to sim 60 ms of startup and a little pulsed load blip. Maybe 6:1 slower with a little leakage inductance. So I only include leakage inductance to tweak the snubber. -- John Larkin Highland Technology, Inc picosecond

A problem encountered with medium-to-fast current-mode flyback switchers, when combining high-ratio multi-winding flyback inductors with...

A problem encountered with medium-to-fast current-mode flyback switchers, when combining high-ratio multi-winding flyback inductors with multipliers: When Q1 switches on, a large current surge flows as Cpump charges from Cmult1 via D2. At Q1, the surge magnitude is multiplied by the transformer ratio. On simulation, U1 senses this via Rs and cuts Q1 off instantly, crippling the switcher -- ...