jmvinay1
Newbie level 4
Hi everyone,
I had designed a cross coupled oscillator on PCB with dielectric constant 3.2 using transistor NE662M04 , johnsons(company) inductors and capcitors at 300Mhz and 2GHz(two different circuits). They worked completely fine on the day of fabrication with slight shift in frequency of oscillation. After a week i tested the same circuits, found both of them not working.
Peculiar behaviors are as follows(there were not seen on the day of fabrication),
1. Circuits current jumped suddenly from 0 to 130mA for the change of voltage from 0.73V to 0.74V. They were showing hysteresis behavior upon decreasing voltage.
2. Oscillation frequencies were same in both the circuit. And were not correlated to LC tank values.
What could be the possible reason for this behavior?Is it a heat related issue during soldering?
Thank you.
Vinay
I had designed a cross coupled oscillator on PCB with dielectric constant 3.2 using transistor NE662M04 , johnsons(company) inductors and capcitors at 300Mhz and 2GHz(two different circuits). They worked completely fine on the day of fabrication with slight shift in frequency of oscillation. After a week i tested the same circuits, found both of them not working.
Peculiar behaviors are as follows(there were not seen on the day of fabrication),
1. Circuits current jumped suddenly from 0 to 130mA for the change of voltage from 0.73V to 0.74V. They were showing hysteresis behavior upon decreasing voltage.
2. Oscillation frequencies were same in both the circuit. And were not correlated to LC tank values.
What could be the possible reason for this behavior?Is it a heat related issue during soldering?
Thank you.
Vinay