Hello! I want to design a circuit for smoke detection using A5303 smoke detector. I used the typical circuit in the datasheet but I have problem with it and it doesn't work as explained in the datasheet.Have anyone worked with this IC before?
this is the datasheet

 

Are you using an optical chamber and all the components as per datasheet?? What's not working?

 

Are you using an optical chamber and all the components as per datasheet?? What's not working?

Yes my circuit is exactly as per datasheet. But I have problem with oscillation frequency that as stated in the datasheet is determined by a capacitor and a resistor that are parallel to each other and are connected to the OSC CAP and Vcc as shown in the below (1500pF and 10MOhm) and is equal to 0.7*C*R. Sometime when I place a cap and res connected to this pin the circuit works and oscillation frequency is correct, but after a while the frequency becomes lower than before!! and this time when I measure the 10 MOhm resistor in the circuit by multi-meter It doesn't show true value and is very lower!! What can be the problem!!?!