On Sun, 11 Sep 2016 17:12:14 -0500, "Tim Williams"
<tiwill@seventransistorlabs.com> wrote:

>"John Larkin" <jjlarkin@highlandtechnology.com> wrote in message 
>news:8jfbtb1hfaceg4vl8psnv8i0i65ove62nv@4ax.com...
>> I just did a diff pair of BFQ18's driving a diff pair of BFQ149's
>> driving, well, more stuff. I was shocked that everything just
>> worked... no oscillations, no weirdness.
>
>Maybe you just couldn't 'hear' it. :^)
>
>On a related subject, I once built a complete type D flip-flop from CML. 
>Just to see how fast 2N3904s can possibly go.  There was too much inductance 
>and delay in the feedback loops though (which, being fairly small signals, 
>is analog feedback too, not hard saturated digital), and it oscillated.  Oh 
>well. ;)
>
>Tim

It just needed some ferrite beads!

Or base resistors, which do pretty much the same thing.


-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics

On Sun, 11 Sep 2016 16:46:51 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>On 09/11/2016 04:31 PM, John Larkin wrote:
>> On Sun, 11 Sep 2016 14:26:51 -0400, Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>
>>> On 09/10/2016 11:47 PM, Tim Williams wrote:
>>>> "Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
>>>> news:fe9caa14-dc46-cd6d-70c8-efafc06fadb1@electrooptical.net...
>>>>> Sometimes.  Power supplies are super slow compared with signal nodes,
>>>>> so you don't have to worry too much about the additional capacitance
>>>>> and length of trace (i.e. antenna) due to building up a discrete RLC
>>>>> network. If you're living in that world, great, but many of us aren't.
>>>>> For example, the Murata 0603 beads are super nice for stabilizing
>>>>> microwave transistors in baseband circuits, where they can do some
>>>>> amazing things.
>>>>
>>>> Yeah, but you go from "power supply" to "small signal" in one paragraph.
>>>> You know what I'm talking about, Phil, and I know you know better than
>>>> to equate them.
>>>>
>>>> The whole point, that I've apparently been a complete and utter failure
>>>> at communicating, over the last four posts, is that power supplies are
>>>> "large signal" and small signals aren't!
>>>
>>> Sure thing--I was agreeing with you about power supply filters, where
>>> you do have the luxury of slowness.
>>>
>>>
>>>> People can't even read, and this is a text-only forum... sigh.
>>>>
>>>>
>>>>> Beads are also useful insurance against board turns--you can replace
>>>>> an unneeded bead with a zero ohm jumper just by changing the BOM, and
>>>>> of course those are always useful for debugging since you can isolate
>>>>> circuit blocks by removing them. ;)
>>>>
>>>> Let's just put in extra tee and pi networks of DNPs and 0-ohms on every
>>>> trace ever.  You'll never have to rev the board again, hell, you can use
>>>> the same board for a hundred other designs just with assembly variants. ;)
>>>>
>>>> I try to avoid jumpers and terminators, if I can.  It clutters the
>>>> design, which causes real delays in layout, for customers who request
>>>> 100% nodal coverage.  Which is often.  They have their place, but not
>>>> every friggin' pin needs it.  Use them prudently, not pervasively.
>>>
>>> Sure.  I usually put a space for one in the base of every transistor
>>> whose f_T > 2 GHz, and add places for extra filter components at the
>>> power entry, even though I may not need them.
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>
>>
>> I just did a diff pair of BFQ18's driving a diff pair of BFQ149's
>> driving, well, more stuff. I was shocked that everything just
>> worked... no oscillations, no weirdness.
>
>Interesting.  Why cascade two pairs of 1-W-class transistors?

Level translation: start near ground, shift up, shift back down. 

>
>Cheers
>
>Phil Hobbs

I did the circuit with SOT23s, and it worked, but they got absurdly
hot. Too much voltage, too much current. SOT89 is a nice little
package.

https://dl.dropboxusercontent.com/u/53724080/Circuits/Fast_Stuff/Fast_Level_Shifter.JPG

This was too easy. Something's wrong.


-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

"John Larkin" <jjlarkin@highlandtechnology.com> wrote in message 
news:8jfbtb1hfaceg4vl8psnv8i0i65ove62nv@4ax.com...
> I just did a diff pair of BFQ18's driving a diff pair of BFQ149's
> driving, well, more stuff. I was shocked that everything just
> worked... no oscillations, no weirdness.

Maybe you just couldn't 'hear' it. :^)

On a related subject, I once built a complete type D flip-flop from CML. 
Just to see how fast 2N3904s can possibly go.  There was too much inductance 
and delay in the feedback loops though (which, being fairly small signals, 
is analog feedback too, not hard saturated digital), and it oscillated.  Oh 
well. ;)

Tim

-- 
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com

On 09/11/2016 04:31 PM, John Larkin wrote:
> On Sun, 11 Sep 2016 14:26:51 -0400, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> On 09/10/2016 11:47 PM, Tim Williams wrote:
>>> "Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
>>> news:fe9caa14-dc46-cd6d-70c8-efafc06fadb1@electrooptical.net...
>>>> Sometimes.  Power supplies are super slow compared with signal nodes,
>>>> so you don't have to worry too much about the additional capacitance
>>>> and length of trace (i.e. antenna) due to building up a discrete RLC
>>>> network. If you're living in that world, great, but many of us aren't.
>>>> For example, the Murata 0603 beads are super nice for stabilizing
>>>> microwave transistors in baseband circuits, where they can do some
>>>> amazing things.
>>>
>>> Yeah, but you go from "power supply" to "small signal" in one paragraph.
>>> You know what I'm talking about, Phil, and I know you know better than
>>> to equate them.
>>>
>>> The whole point, that I've apparently been a complete and utter failure
>>> at communicating, over the last four posts, is that power supplies are
>>> "large signal" and small signals aren't!
>>
>> Sure thing--I was agreeing with you about power supply filters, where
>> you do have the luxury of slowness.
>>
>>
>>> People can't even read, and this is a text-only forum... sigh.
>>>
>>>
>>>> Beads are also useful insurance against board turns--you can replace
>>>> an unneeded bead with a zero ohm jumper just by changing the BOM, and
>>>> of course those are always useful for debugging since you can isolate
>>>> circuit blocks by removing them. ;)
>>>
>>> Let's just put in extra tee and pi networks of DNPs and 0-ohms on every
>>> trace ever.  You'll never have to rev the board again, hell, you can use
>>> the same board for a hundred other designs just with assembly variants. ;)
>>>
>>> I try to avoid jumpers and terminators, if I can.  It clutters the
>>> design, which causes real delays in layout, for customers who request
>>> 100% nodal coverage.  Which is often.  They have their place, but not
>>> every friggin' pin needs it.  Use them prudently, not pervasively.
>>
>> Sure.  I usually put a space for one in the base of every transistor
>> whose f_T > 2 GHz, and add places for extra filter components at the
>> power entry, even though I may not need them.
>>
>> Cheers
>>
>> Phil Hobbs
>
>
> I just did a diff pair of BFQ18's driving a diff pair of BFQ149's
> driving, well, more stuff. I was shocked that everything just
> worked... no oscillations, no weirdness.

Interesting.  Why cascade two pairs of 1-W-class transistors?

Cheers

Phil Hobbs


-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

On Sun, 11 Sep 2016 14:26:51 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>On 09/10/2016 11:47 PM, Tim Williams wrote:
>> "Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
>> news:fe9caa14-dc46-cd6d-70c8-efafc06fadb1@electrooptical.net...
>>> Sometimes.  Power supplies are super slow compared with signal nodes,
>>> so you don't have to worry too much about the additional capacitance
>>> and length of trace (i.e. antenna) due to building up a discrete RLC
>>> network. If you're living in that world, great, but many of us aren't.
>>> For example, the Murata 0603 beads are super nice for stabilizing
>>> microwave transistors in baseband circuits, where they can do some
>>> amazing things.
>>
>> Yeah, but you go from "power supply" to "small signal" in one paragraph.
>> You know what I'm talking about, Phil, and I know you know better than
>> to equate them.
>>
>> The whole point, that I've apparently been a complete and utter failure
>> at communicating, over the last four posts, is that power supplies are
>> "large signal" and small signals aren't!
>
>Sure thing--I was agreeing with you about power supply filters, where 
>you do have the luxury of slowness.
>
>
>> People can't even read, and this is a text-only forum... sigh.
>>
>>
>>> Beads are also useful insurance against board turns--you can replace
>>> an unneeded bead with a zero ohm jumper just by changing the BOM, and
>>> of course those are always useful for debugging since you can isolate
>>> circuit blocks by removing them. ;)
>>
>> Let's just put in extra tee and pi networks of DNPs and 0-ohms on every
>> trace ever.  You'll never have to rev the board again, hell, you can use
>> the same board for a hundred other designs just with assembly variants. ;)
>>
>> I try to avoid jumpers and terminators, if I can.  It clutters the
>> design, which causes real delays in layout, for customers who request
>> 100% nodal coverage.  Which is often.  They have their place, but not
>> every friggin' pin needs it.  Use them prudently, not pervasively.
>
>Sure.  I usually put a space for one in the base of every transistor 
>whose f_T > 2 GHz, and add places for extra filter components at the 
>power entry, even though I may not need them.
>
>Cheers
>
>Phil Hobbs


I just did a diff pair of BFQ18's driving a diff pair of BFQ149's
driving, well, more stuff. I was shocked that everything just
worked... no oscillations, no weirdness.


-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

On 09/10/2016 11:47 PM, Tim Williams wrote:
> "Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
> news:fe9caa14-dc46-cd6d-70c8-efafc06fadb1@electrooptical.net...
>> Sometimes.  Power supplies are super slow compared with signal nodes,
>> so you don't have to worry too much about the additional capacitance
>> and length of trace (i.e. antenna) due to building up a discrete RLC
>> network. If you're living in that world, great, but many of us aren't.
>> For example, the Murata 0603 beads are super nice for stabilizing
>> microwave transistors in baseband circuits, where they can do some
>> amazing things.
>
> Yeah, but you go from "power supply" to "small signal" in one paragraph.
> You know what I'm talking about, Phil, and I know you know better than
> to equate them.
>
> The whole point, that I've apparently been a complete and utter failure
> at communicating, over the last four posts, is that power supplies are
> "large signal" and small signals aren't!

Sure thing--I was agreeing with you about power supply filters, where 
you do have the luxury of slowness.


> People can't even read, and this is a text-only forum... sigh.
>
>
>> Beads are also useful insurance against board turns--you can replace
>> an unneeded bead with a zero ohm jumper just by changing the BOM, and
>> of course those are always useful for debugging since you can isolate
>> circuit blocks by removing them. ;)
>
> Let's just put in extra tee and pi networks of DNPs and 0-ohms on every
> trace ever.  You'll never have to rev the board again, hell, you can use
> the same board for a hundred other designs just with assembly variants. ;)
>
> I try to avoid jumpers and terminators, if I can.  It clutters the
> design, which causes real delays in layout, for customers who request
> 100% nodal coverage.  Which is often.  They have their place, but not
> every friggin' pin needs it.  Use them prudently, not pervasively.

Sure.  I usually put a space for one in the base of every transistor 
whose f_T > 2 GHz, and add places for extra filter components at the 
power entry, even though I may not need them.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message 
news:fe9caa14-dc46-cd6d-70c8-efafc06fadb1@electrooptical.net...
> Sometimes.  Power supplies are super slow compared with signal nodes, so 
> you don't have to worry too much about the additional capacitance and 
> length of trace (i.e. antenna) due to building up a discrete RLC network. 
> If you're living in that world, great, but many of us aren't. For example, 
> the Murata 0603 beads are super nice for stabilizing microwave transistors 
> in baseband circuits, where they can do some amazing things.

Yeah, but you go from "power supply" to "small signal" in one paragraph. 
You know what I'm talking about, Phil, and I know you know better than to 
equate them.

The whole point, that I've apparently been a complete and utter failure at 
communicating, over the last four posts, is that power supplies are "large 
signal" and small signals aren't!

People can't even read, and this is a text-only forum... sigh.


> Beads are also useful insurance against board turns--you can replace an 
> unneeded bead with a zero ohm jumper just by changing the BOM, and of 
> course those are always useful for debugging since you can isolate circuit 
> blocks by removing them. ;)

Let's just put in extra tee and pi networks of DNPs and 0-ohms on every 
trace ever.  You'll never have to rev the board again, hell, you can use the 
same board for a hundred other designs just with assembly variants. ;)

I try to avoid jumpers and terminators, if I can.  It clutters the design, 
which causes real delays in layout, for customers who request 100% nodal 
coverage.  Which is often.  They have their place, but not every friggin' 
pin needs it.  Use them prudently, not pervasively.

Tim

-- 
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com

"John Larkin" <jjlarkin@highlandtechnology.com> wrote in message 
news:c649tbdk8tot755c202ioa441fccai26sd@4ax.com...
> Several of those parts hold up well at 1 amp, and even 3 amps.

Really?  I'd love to see the VNA plots.

Tim

-- 
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com

On 09/10/2016 06:20 PM, Tim Williams wrote:
>
> If you need a lossy inductor, you're /far, far better off/ constructing
> one yourself.

Sometimes.  Power supplies are super slow compared with signal nodes, so 
you don't have to worry too much about the additional capacitance and 
length of trace (i.e. antenna) due to building up a discrete RLC 
network.  If you're living in that world, great, but many of us aren't. 
For example, the Murata 0603 beads are super nice for stabilizing 
microwave transistors in baseband circuits, where they can do some 
amazing things.

Beads are also useful insurance against board turns--you can replace an 
unneeded bead with a zero ohm jumper just by changing the BOM, and of 
course those are always useful for debugging since you can isolate 
circuit blocks by removing them. ;)

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net