Tranistor or FET recommendation

Jul 24, 2012 3 Replies

I have a movement detector producing 0V at idle and up to 0.4V-0.5V when th= ere is a movement. This output goes to another device whose logic level Hig= h Vih is > 1.3V and Low is


there is a movement. This output goes to another device whose logic level H= igh Vih is > 1.3V and Low is <0.4V. Any suitable transistor or FET wi= th very low leakage (few uA)current in both On and OFF states and in a smal= l package. Voltage available on board is 1.8V.

A transistor or FET is not appropriate for that application. You want a com= parator such as this :

formatting link
available from places like Mouser for $0.33. Use the Figure 5 in the data s= heet except change the 220K to 1.0M and the 100K with 120K. The 1.8V VCC pl= ugs in where they show 5V.

n there is a movement. This output goes to another device whose logic level= High Vih is > 1.3V and Low is <0.4V. Any suitable transistor or FET = with very low leakage (few uA)current in both On and OFF states and in a sm= all package. Voltage available on board is 1.8V.

omparator such as this :

formatting link

sheet except change the 220K to 1.0M and the 100K with 120K. The 1.8V VCC = plugs in where they show 5V.

That's perfect. Thanks.

doesn't need a special transistor:

+1.8 ---+---------+ | | | [1M] | | | +------- out [1M] C / | |/ +------| NPN eg: bc547 | |\ [1M] E \ | | 0V ---+--- | | in ---------------'
?? 100% natural --- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required