Re: Active bridge rectifier using cmos hex inverters, was Using zener diode to protect test circuit?

On Sun, 24 Apr 2005 07:53:28 -0700, Jim Thompson
<thegreatone@xxxxxxxxxxx> wrote:

>On 24 Apr 2005 04:21:05 -0700, Winfield Hill
><hill_a@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
>>Jim Thompson wrote...
>>>
>[snip]
>>>
>>> It works if you...
>>> Tie input of upper inverter to lower "IN"
>>> Tie input of lower inverter to upper "IN"
>>> Cute! I'll use it ;-)
>>
>> That's right, thanks! I messed-up when translating my first
>> drawing to the second one. Here's the corrected schematic.
>>
>>. _Vdd ----- + out
>>. / |
>>. IN ---+--O< |--,
>>. | \_| | Active bridge rectifier
>>. unknown \________|_ using cmos hex inverters
>>. polarity ________| |
>>. / _ |
>>. | / | |
>>. IN ---+--O< |----'
>>. \_|
>>. Vss ----- - out
>>
>> Again, someone must have invented this long ago. Sometime shortly
>> after the first cmos hex inverters came out in the mid 60s, or at
>> least soon after cmos became available in low-cost plastic packages
>> about 35 years ago... But now we can make it with a micro-miniature
>> ON Semi NL27WZ04 MiniGate? in a SC70-6 package, a 2.1 x 2.1mm dust
>> flake. See http://www.onsemi.com/site/content/0,,1241,00.html and
>> http://www.onsemi.com/pub/Collateral/NL27WZ04-D.PDF
>>
>> Using the FETs in a low-voltage cmos process allows us to use this
>> technique down to 1.5V or even less, although of course the FET's
>> on resistance goes up at low voltages. Has anyone seen an Ron vs
>> Vdd plot for these low-voltage logic families? ON Semi's NL17SV04
>> is claimed to work well at 0.9V supply, and deliver 50MHz at 1.2V.
>>
>> BTW, although the fabulous MiniGate logic sample kit is no longer
>> available free from ON Semi, it's offered by DigiKey for only $39.
>> Search on MINIGATEA-KIT. Break out those microscopes!
>
>I simulated it with basically a 74HCU04 structure (UNBUFFERED
>Inverter).
>
>That is a SINGLE inverter stage.
>
>I don't know quite what it will do with a 74HC04 (each 'inverter' is
>actually 3-stages long).
>
>I'll try that next.
>
> ...Jim Thompson

Interesting result is that the 74HC04 isn't as good as the simple
74HCU04 near zero, and has no better load capability since that is
limited by the rail voltage determining the gate voltage of the main
stage.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

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