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Forum Index : Microcontroller and PC projects : how do connect the ps/2 keyboard connector  to this 2N700

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tenij000
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Joined: 30/05/2025
Location: Netherlands
Posts: 31
Posted: 09:57am 17 Jul 2025
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dont now how this 2N700 is connected





3v3 connected to pin 3 ?

gp8 connected to pin 1 and 2

pin 3 connected clock
 
Mixtel90

Guru

Joined: 05/10/2019
Location: United Kingdom
Posts: 7889
Posted: 10:19am 17 Jul 2025
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How do you mean? That's a conventional level shifter circuit using a common N-channel mosfet.
GP8 - source - pin 1
3V3 - gate - pin 2
PS2 CLK - drain - pin 3

If you look at the mosfet from the top with the flat side towards you the pins are in 1-2-3 order left to right.

What you have labelled as pin 2 is wrong. On a mosfet symbol the source is indicated by both what you have labelled as pin 1 and the centre line with the arrow on it. The direction of the arrow shows weather it is N-channel )towards the gate) or P-channel (away from the gate).
Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs
 
javavi

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Joined: 01/10/2023
Location: Ukraine
Posts: 496
Posted: 10:27am 17 Jul 2025
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3v3  connected to pin 2 - GATE

GP8 connected to pin 1 - SOURCE

CLOCK connected to pin 3 - DRAIN
Edited 2025-07-17 20:32 by javavi
 
tenij000
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Joined: 30/05/2025
Location: Netherlands
Posts: 31
Posted: 10:40am 17 Jul 2025
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like this


 
stanleyella

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Joined: 25/06/2022
Location: United Kingdom
Posts: 2548
Posted: 07:34pm 18 Jul 2025
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https://nl.aliexpress.com/item/32890488553.html?
 
EDNEDN
Senior Member

Joined: 18/02/2023
Location: United States
Posts: 147
Posted: 10:18pm 18 Jul 2025
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  stanleyella said  https://nl.aliexpress.com/item/32890488553.html?


I have used these exact modules a number of times.   They work well, but they do delay the signal noticeably.   I had the clock not routed though the converter but the data was routed through the converter.  And I could not reliably latch the data.
 
phil99

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Joined: 11/02/2018
Location: Australia
Posts: 2626
Posted: 11:08pm 18 Jul 2025
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The 10kΩ pullups are a bit high for speed.
On the 3.3V side 1.8kΩ and 2.7kΩ on the 5V side would be better.

If that still isn't enough 680Ω and 1kΩ are as low as I would go.
 
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