POWER MANAGEMENT SECTION 14
Page 14-2 RPC-320
Currents are maximum and minimum as specified by the
manufacturer. Min-max current ranges "guaranteed" by
the device manufacturer have a tremendous range, often
by a factor of 10 or m ore. Current above is “typical” .
Some current consumption is difficult to determine.
Digital outputs, for example, will draw virtually no
current under no load conditions, but can supply 15 ma
to each output if required. Therefore, inputs and outputs
connected to the card will affect its current consumption.
Some chips, such as U9, will not draw much current
unless there is activity on the RS-485 port.
Board current consumption may be affected by the
setting of jumper W7. T his jumper determines if inputs
at J3 are pulled up or down. When set to pull up inputs,
each line forced low increases current consumption by
50 uA. If all inputs are tied to + 5V or ground,
removing jumper W7 may dr aw less current.
The application program IC in U6 may be changed to a
29C040. This 512K byte memory draws 200 uA less
current than a 32K byte one.
Any contr ol line from P2 to ground draws 500 uA due to
the 10K pull-ups. Lines at P6 are pulled to + 5V
through a 10K resistor. Each low line draws 500 uA.
The contrast adjustment (R18) can be removed or
adjusted for minimum cur rent.
Program Example
This example makes the RPC-320 go into its lowest
power mode.
10 ONITR 500
.
. other code
.
100 IDLE 2
200 GOTO 100
500 PRINT "In interrupt"
510 RETI
