VIPER Technical Manual

Power and power management

 

 

Power estimate examples

Example 1: VIPER [Linux] asleep (microprocessor in sleep mode and every power saving option enabled)

In this case, the power consumed by the respective categories is:

•VIPER current (Linux default) = 334mA ±3mA.

•Power saving = 285mA (all power saving options enabled).

•External peripheral current = 0mA.

Therefore, the estimated VIPER current is:

334mA ±3mA - 285mA + 0mA = 49mA ±3mA (245mW ±15mW).

Example 2: VIPER [Linux] at 200MHz in performance mode + LCD with backlight on

In this case, the power consumed by the respective categories is:

•VIPER current while idle = 334mA ±3mA - 7mA = 327mA ±3mA. VIPER current while active = 334mA + 47mA ±20mA = 381mA ±20mA.

•Power saving = 0mA.

•External peripheral current = 650mA (LCD).

Therefore, the estimated VIPER current while idle (min) is:

327mA ±3mA + 650mA

=977mA, ±3mA (4885mW, ±15mW).

and the estimated VIPER current while active (max) is:

381mA ±20mA + 650mA

= 1031mA, ±20mA (5155mW, ±100mW).

© 2007 Eurotech Ltd Issue E

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