Yann Guidon / YGDESIt's not exactly related to Ted Yapo's blog https://hackaday.io/project/162998-the-rise-and-fall-of-pulses/log/158851-a-toy-diode-sampler but it's close...
Inspired by Curious Marc's recent video:
I had to try a sim with Circuitjs and it works like a charm !
Why does it matter to me ?
Because I have struggled a LOT to make a DFF gate with bipolar transistors... I had found a version that looked promising for a latch but it became unstable when connected to other devices.
The insights of this pass gate could probably help solve this enigma at last.
Oh and I should get the polarities right....
And then, there is this gem : https://w140.com/tekwiki/images/9/97/Frye_s4_gate.pdf where the value is sampled at the falling edge, almost working as a DFF but with diodes.
Discussions
Become a Hackaday.io Member
Create an account to leave a comment. Already have an account? Log In.
You're overthinking this. To get a divide by two gate using a DFF, just use a 2 transistor bistable with steering diodes like in Figure 19 of https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_6 It needs 4 active parts, 2 transistors and 2 diodes (or 2 transistors used as diodes, generally the BC junction, perhaps ones that are not so good as transistors). Also 2 capacitors as it's capacitively coupled.
I used this bistable configuration in the bad old days to square up a very asymmetrical waveform from a Garner oscillator.
Are you sure? yes | no