I'm using ADAU1446 DSP.
We are performing temperature testing, but during high temp. testing the ADAU1446 dose not work as we expecting.
Temperture range in datasheet is -40 to +105 cel. degree, but the DSP fail is occurred from lower temp. than datasheet.
We monitoring DSP surface temperature. The DSP start to fail from -87 cel. degree surface temp.
The ambient temp is 71 cel. degree when the DSP fail is occurred.
The failure symptoms are as below :
1. The DSP boot-up in normal but start to show abnormal performance within 20 seconds.
2. Sometimes audio disgnal routing is normal but volume control is not normal.
3. Sometimes core run bit is normal (we can read 0xE228), but other functions not normal.
We using 1.5A regulator for DSP and 5 AD1938 CODECs. Probably, the regulator current capacity can make above problems?
Or, what we can investigate regarding above issues?