ADA4807-2 become very heat when it put-in a ±5v circuit,but AD8762 is normal。
Could you share your schematic? We can start with that so we can troubleshoot your circuit and see what causes the problem. How hot does your device get?
You can also approximate your junction temperature using the formula below:
where. TA is the ambient temp, Theta-JA is given in the datasheet and PD is power dissipation using the formula:
Isy x Vsy refers to the quiescent power dissipation.Iload x (Vsy - Vout) is the power dissipation at the output stage of the transistor.
Also, you have to multiply Pd depending on the number of channels you are using.If you have any clarifications, please let us know.
1. the device（ADA4807） will reach 100℃ after about 10 second.
2. The schematic as follow.
Thank you for your replay.
could you give me some advice base on the schematic. I can't find the reason,why does the ADA4807-2 generate heat? look forward to your reply. thank you.
Can you give what your input signal(voltage and frequency) is and what signal source it came from? Could you also check if the components on your board are all properly connected.
Thank You for your reply.
I don't give input signal, I just solder ADA4807 on the PCB, and I have try another ADA4807, but all of them generate heat .
when I use AD8671 or ADA4841, they are normal. they have same the define of Pin.
Hi,Do you mean that your input pins are floating? It is not recommended that the inputs are left floating, the input bias current will need a path to flow and floating the inputs will cause it to be on an undefined state. Try giving your inputs a defined source or tie it up to GND.Regards,Goz
Hi,Have you tried putting your inputs to GND? After that try to measure the output with a DMM if it gives the proper voltage. You should measure a near to zero voltage.Regards.
Thank you for your patient reply.
I have put the inputs to GND and measured the outputs, Vpp=360mmV, Vrms=2.66V. However, tADA4807-2 is still very hot.
Hi,I don't see any mistakes on your schematic, the configuration is a simple gain of 2.
Could you take a picture of the ADA4807 on PCB?Can you show how you measured your output voltages?I am suspecting that there maybe a short in your circuit.Regards,Goz
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