How to design a 1s period 10% duty cycle square wave OSC?

[leonken]

The period is 1 second, duty is 10%(100ms).
How to design such square wave osc and integrated on one chip?
Thank you

 

[btbass]

You could use a low pin count micro from Microchip and a clock crystal for the timebase.

 

[mami_hacky]

Re: How to design a 1s period 10% duty cycle square wave OSC

For this range low cost and simple analog pulse shapeing circuits are avilable!

 

[sunking]

Re: How to design a 1s period 10% duty cycle square wave OSC

osc and a counter.
Smitt trigger also can do it

 

[papyaki]

Re: How to design a 1s period 10% duty cycle square wave OSC

Hi,

This can easely be done with two old NE555. The first one as astable oscillator followed by a second in a monostable configuration. The first one determine the frequency and the second determine the duty cycle.

Datasheet : h**p://www.fairchildsemi.com/ds/NE/NE555.pdf

* = t