Current Drain Of Digital Electronics - Mallinckrodt NELLCOR NPB-4000 Service Manual

13.17 CURRENT DRAIN OF DIGITAL ELECTRONICS

Section 13: Microprocessor Computer and Control –Theory of Operation
The current drain has been determined by using the maximum numbers in the
data sheets of the devices. Typically, the devices operate significantly lower.
386EX
4M DRAM
4M FLASH
LCD CNTLR
256k SRAM
DUART
RS232 XCVR
256k FLASH
RTC
40MHz osc
Subtotal =
misc. logic
Grand Total =
Available Power =
130 mA
95 mA
30 mA
20 mA
50 mA x2 = 100 mA
3 mA
5 mA
15 mA
15 mA
9 mA
422 mA
78 mA
500 mA
3.3 volts x 500 mA = 1.65 W
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