On Tue, 23 Sep 2008 08:42:23 -0700, John Larkin
wrote:
On Tue, 23 Sep 2008 08:33:04 -0700, Jim Thompson
wrote:
On Tue, 23 Sep 2008 08:18:58 -0700, John Larkin
wrote:
On Tue, 23 Sep 2008 08:07:40 -0700, Jim Thompson
wrote:
I need to convert a _slow_ moving analog signal to "1" or "0",
depending on whether it is above or below the digital threshold
(CMOS).
Problem: If I go directly into a gate or D-input of a flop I can get
substantial overlap current rail-to-rail.
This is a very low current application.
Any suggestions?
...Jim Thompson
What's the technology... discrete or inside an IC?
Inside an IC, I'm designing it.
How low is "low current"
1uA
Speed/hysteresis requirements?
I have ~10us to make a decision, no hysteresis (yet).
What's the input signal level?
John
0V-to-3.3V CMOS levels, out of a _very_ slow comparator.
...Jim Thompson
How about a couple of common-base (or common-gate) stages. Input goes
to emitters; PNP base is maybe 1 volt below Vcc; NPN base is +1 from
ground, both base drives weak if it's bipolars, anything for fets.
Collectors/drains connected together are the output.
John
So its output is "0", "1", or FLOAT ?:-)
...Jim Thompson
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