Are watts per MHz linear?

In looking at various 32-bit MCUs, I've seen watts per MHz mentioned. A linuxdevices.com news article talks about Powerpc 405: "Power usage is listed as 0.2mW/MHz".

So lets take the simple PIC. Can I clock it down and watch power usage go down linearly? If a chip is 10mA at 10MHz, will it be 10uA at 10kHz? I take it theres always a base current at DC. so the equation should be (K x MHz) + Base leak at DC.

Is this correct for a fixed temperature and pressure? Can I rely on this equation for extreme low power designs?

Reply to
Ghazan Haider
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I'd only rely on it if it's specified in the data sheet, NOT a press release. If it's quoted as a "typical" value, I'd give it an order of magnitude either way. Also, not all designs are amenable to very low clock speeds. Not familiar enough with the PPC to know if it's good down very close to a "DC clock."

--
Rich Webb   Norfolk, VA
Reply to
Rich Webb

Microchip is kind enough to provide us with the "Electrical characteristics" of their chip (usually at the end of a datasheet). I'm looking at a 18F2550 right now, and it's not linear in respect to Watt/Fosc.

Have a look at the datasheet for the device of your choice, it's all there. Good luck!

// Erik N=E4slund

Reply to
eKIK

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