(1). Schematics: from below , you can see situation of application, AIB2 is input analog voltage :0-10V, VOLT_ADC is output voltage :0-1.81V.
(2). Different batch IC
|
Description 2 |
Name |
Part number |
Quantity |
Manufacturing date |
Status |
|
70CPE02358 |
NATIONAL SEMICONDUCTOR |
LMC660AIMX/NOPB |
2500 |
2013/1/4 |
Stock: 2384 |
|
70CPE02358 |
NATIONAL SEMICONDUCTOR |
LMC660AIMX/NOPB |
1550 |
2010/10/18 |
Used up |
|
70CPE02358 |
NATIONAL SEMICONDUCTOR |
LMC660AIMX/NOPB |
550 |
2010/12/30 |
Used up |
We used the batch(2010/10/18 and 2010/12/30), when input voltage(AIB2) is 4Vdc, the voltage output(VOLT_ADC) after Amp is stable(yellow is amp output). It is good!
When supplier changed to new batch(2013/1/4) which is used for the first time, when input voltage(AIB2) is also 4Vdc, the voltage output(VOLT_ADC) after amp is not stable(yellow), output voltage occurred oscillation ! Freq=1.4MHz, AM=160mV.
Why using the same IC which batch is only different, the output voltage occurred oscillation? Please give us some support about this issue as soon as possible! Thanks!
