Hello TI !
Is there any information about how the input parameters of this part react to change of humidity level?
Maybe graph like this?
I have a problem with floating output with hum level near 80% and above. And i want to find out this is the problem with pcb tracing or with LMP7701 itself.
Best regards,
Ilia
Hi, Kai
Pcb is located inside Faraday cage. I used 2 layer stack FR4. There is no mask and silkscreen on board. Before LMP7701 we used ada4530 from analog and everything was fine without guard ring. I thought(maybe wrong) in terms of 2 layers FR4 pcb and humidity guard ring is not effective.
Ilia.
Ilya,
We perform (or qualify by similarity) Moisture Sensitivity Level tests (MSL) and Highly Accelarated Stress Test (HAST) on all of our products including LMP7701 but we do not test our parts for the change of specific parameters at different relative humidity levels - they just must pass the datasheet electrical min/max limits and package must have no sign of delamination.
Moisture sensitivity level relates to the packaging and handling precautions for some semiconductors. The MSL is an electronic standard for the time period in which a moisture sensitive device can be exposed to ambient room conditions (30 °C/85%RH at Level 1; 30 °C/60%RH at all other levels).
Moisture/reflow sensitivity classification for plastic[1] Integrated circuit (IC) SMDs, there are eight levels of moisture sensitivity. Components must be mounted and reflowed within the allowable period of time (floor life out of the bag).
Both packages of LMP7701 (SOIC and SOT-23) are classified as MSL 1
Below are the conditions for testing to Level 1 MSL.
CSAM
Level 1 indicates parts are Not Moisture Sensitive.
LMP7701 packages are also qualified under 130°C/85% RH HAST test
Ilya, Kai has a point that your circuit would not work the way it is shown because of its positve feedback (feedback must be negative). This is true unless there is another inversion in the signal path that you do not include on your schematic. If there is nothing else, you need to swap connections to pin 3 and 4 (see below) or DOUT will be stuck at one of the rails (at 5V or -5V).
