KCC's Quizzes AQQ305 about a mutual exponentiation equation
1. Quote of the month: "A train station is where a train stops. A bus station is where a bus stops. I have a work station on my desk, so..." - unknown
2. Quiz AQQ305 about finding a mutual exponential equation
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September Monthly Blog Quiz! Read the blog, take the quiz, and you could win a gift card
Quiz: How Well Do You Know Adaptive Power Switching?
Is your I/O module overheating? The AD74416H's Adaptive Power Switching (APS) can cut heat dissipation by up to 40% — but how well do you really understand how it works?
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LTC3351
Recommended for New Designs
The LTC3351 is a backup power controller that charges and monitors a series stack of one to four supercapacitors. The LTC3351’s synchronous step-down...
Datasheet
LTC3351 on Analog.com
I am using the LTC3351 in my design with the charging voltage set to 19.5V.
I have observed that the CAPGD signal exhibits instability or bouncing when transitioning from Low to High.
Could you please advise on the possible causes of this behavior?
Hi NK304 ,
Could be a layout issue.
Instead of measuring the SCAP voltage (over supercap terminals?), measure the voltage at R44. Do you see any ripple there?
Could also try adding some positive feedback by placing a high ohmic resistor from CAPFB to CAPGD (not sure if works, may cause instability).
Cheers, heke
Dear heke,
Thank you very much for your advice.
Regarding the waveform at R44, I observed noise of approximately 300–400 mVp-p at 500 kHz. Additionally, the bounce on CAPGD occurred at around 250 kHz. Does this suggest that switching noise is affecting the circuit due to a layout issue, possibly related to the GND plane?
After adding a 470 kΩ resistor between CAPFB and CAPGD, the bounce was suppressed. Could you please explain what effect this resistor has in the circuit? Also, is 470 kΩ an appropriate resistance value for this purpose?
Best regards,
