[SOLVED] cmos circuit for convection of oscillator waveform into pulse or square waveform

[Debasish_Halder]

How can I convert a oscillator waveform (0.4 v amplitude ,500hz)shown in the pictures into pulse or square waveform. kindly suggest me any cmos ckt that can be run in 0.4 V supply voltage for this conversion.

 

[memarian]

How can I convert a oscillator waveform (0.4 v amplitude ,500hz)shown in the pictures into pulse or square waveform. kindly suggest me any cmos ckt that can be run in 0.4 V supply voltage for this conversion.View attachment 117366View attachment 117367View attachment 117368View attachment 117369

Hi,

You can easily use a comparator Like LM293 , LM339, LM319, ... etc. These comparators have open collector output, just a pull-up resistor to your desired voltage like 15V, 5V or 3.3V.

You can compare the voltage with 0V (GND) or if you want you can use 2 comparators as a window detector (for Example +0.1 , -0.1V). Check their Datasheet for Many Interesting Circuits.

LM293 Datasheet
LM339 Datasheet
LM319 Datasheet

 

[hobbyckts]

Comparator circuit can provide a solution to you.

 

[Debasish_Halder]

but 0.4 v comparator ie. sub-threshold comparator will not give a perfect square wave from the above waves.

 

[Debasish_Halder]

Can I use cmos sub-threshold schmitt trigger with 0.4V supply? is that give a perfect square ?

 

[memarian]

Comparator circuit can provide a solution to you.

Hi,

It seems that i missed something :

your Power Supply voltage is 0.4V or Your input has 0.4V amplitude?

if your input voltage has 0.4V amplitude, there will no problem using comparators like LM319, ...etc

BUT if your power supply voltage is 0.4V , simply i don't know! it seems to me that this is some part of IC design and i think you should ask your question in IC Design Section.

 

[D.A.(Tony)Stewart]

Present sub-threshold CMOS inverter is guaranteed to work at 0.7Vmin

https://www.digikey.com/product-detail/en/74AXP1G14GNH/74AXP1G14GNH-ND/5169911

Trivial relaxation oscillator at 500 Hz might use 1M feedback and 470 pF cap from input to ground.

 

[Debasish_Halder]

Well thank u so much friends... I have done it. By the way my waveform is generated from a 0.4 V supply voltage oscillator circuit.