Tool/software:
Hello Team,
I am working on LM5156HQPWPRQ1 PWM controller IC. And I have seen that IC is malfunctioning.
when voltage is given externally at EN (pin 14), seeing voltage at BIAS (pin 1) pin. So, I want to understand is there any circuit connected b/w EN and BIAS pins internally. If yes, could you provide that circuit details or could you explain the reason for that voltage at BIAS pin.
Thank you,
Tejasri.
Hi Tejasri,
Yes, there is an internal ESD protection diode.
This is why there is the following abs. max. given in the datasheet:
Best egards
Moritz
Hello Moritz,
Thanks for the reply.
Need some more details on that. How that ESD diode is connected ? Like which way cathode and anode are connected ?
My scenario is giving 4.8V at EN pin and I am seeing 3.619 at EN pin (pin 14) and 2.858 at BIAS pin (pin 1) in the measurements.
Could you let me know ESD diode part number or forward voltage of that ?
Kindly help me in this.
Thank you,
Tejasri.
Hi Tejasri,
The diode is connected like this:
This diode has no partnumber, as it is implemented as a structure inside the silicon.
Unfortunately i cannot tell you more about this.
Please operate the device only in the specified area.
Best regards
Moritz
