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CSD18543Q3A: Rise Time compared to CSD18563Q5A

Part Number: CSD18543Q3A
Other Parts Discussed in Thread: CSD18563Q5A


the datasheet states a rise time  of 18ns at V_GS=10V and I_DS=12A for the CSD18543Q3A. This appears rather slow compared to the CSD18563Q5A with a rise time of 6.3ns at V_GS=10 and I_DS=18A.

Since the Gate Charge of the CSD18543 is smaller than the Gate Charge of the CSD18563 i would assume a shorter rise time.

Is the rise time of the 18543 really that high?



  • Hi Jan,
    Thanks for your question. The switching times in the FET datasheets are not always the best way to determine how fast the FET is going to switch in the actual application as they are highly dependent upon the test conditions and board used to do the testing. These two devices were released 3 years apart and most likely used a different test board when measuring the switching times. A better indicator is the RG x QG time constant from those parameters specified in the datasheet. I would agree that a lower gate charge device should switch faster than a device with higher QG. Please take a look at this blog for more information: