8-bit MicrocontrollersのトピックRe: LC60: Stop3 mode supply current Typical vs Max

LC60: Stop3 mode supply current Typical vs Max

BasePointer — Sun, 23 Dec 2007 03:05:17 GMT

Hi,

MCU is MC9S08LC60. Stop3 mode supply current in A.6 Supply Current Characteristics in the datasheet indicated typically 660nA. But 20μA as maximum. This values are so different and I wonder maximum value depends on temperature or mcu in mass production in 25°C?

How should I interpret these values in datasheet:

May any LC60 at 25°C consume current 20μA in stop3 mode? If yes, I want to learn the ratio.

or it means, All LC60 at 85°C consume current 20μA in stop3 mode?

I mean what is typical, what is maximum for this parameter?

I have a battery powered application that is capable of working in -40°C/+85°C.

If the value is 660nA for all LC60 at 25°C and it may vary to 20μA over temperature, this is acceptable for our application.

If the value is 660nA for most LC60 but 20μA for fews at 25°C, this is not acceptable and We have to control this value at our mass production.

Regards,

BP.

Re: LC60: Stop3 mode supply current Typical vs Max

bigmac — Sun, 23 Dec 2007 09:31:41 GMT

Hello BP,

The specification of 20 uA max (as yet a preliminary, tentative value on my release of the data sheet) is applicable to a die temperature of 85C. In general, the current should rapidly increase as the temperature increases above 25C.

If you need to estimate what the maximum value might be at somewhat lower temperatures, perhaps you could look at the data sheets for other devices, where the stop mode current versus temperature plot is published. I might expect the ratio of currents at different temperatures to be similar for the LC60.

If you intend that the equipment should operate for prolonged periods at the temperature extremes, you will also need to take into account the effect on battery capacity at these extremes.

Regards,

Mac

Re: LC60: Stop3 mode supply current Typical vs Max

BasePointer — Mon, 24 Dec 2007 21:42:04 GMT

Hi Mac,

I wonder the maximum current value consumed by MCU in stop3 at 25°C. How much is it? Is It always 660nA for every LC60 produced? I need maximum value at 25°C.

For 85°C, I looked at GT60A Dataheet, its values are acceptable.

GT60A, Vdd=3V, STOP3 Current

~650nA at 25°C

~3.4μA at 70°C

~6.2μA at 85°C

If so, Why does the datasheet indicate this for LC60 as 20μA?

10x,

BP.

Re: LC60: Stop3 mode supply current Typical vs Max

bigmac — Thu, 27 Dec 2007 14:49:51 GMT

Hello,

My reading of the GB/GT data sheet (Rev 1.00) is somewhat different than the figures you have given. The maximum limit for STOP3 current (3V), within Table A.6, seems to be -

55C 4.3uA

70C 7.2uA

85C 17uA

If I were to hazard a guess for the LC60, I would say you should allow at least 5uA for the 25C maximum current for STOP3, with no peripherals enabled. If the actual figure is critical to your application, you will probably need to measure it for each instance.

Regards,

Mac

Re: LC60: Stop3 mode supply current Typical vs Max

Sam_1979 — Fri, 28 Dec 2007 16:04:09 GMT

Hi, BP

In the datasheet , you can find the notes under the supply current characteristics table, and note1 said that " Typical are measured at 25C. And also can find another chart on page 333, tpyical room temp sidd3 under the different voltage.

regards.