Appendix A HOW TO MEASURE CURRENT CONSUMPTION
52
EPSON
S5U1C17801T1100 HARDWARE MANUAL
(SOFTWARE EVALUATION TOOL FOR S1C17801)
until being reset.
When this circuit is actually used for your circuit, a proper pull-down resistance value must be selected because the
value affects the current consumption of total system.
(When R
21
=
100
K
Ω
IR
21
=
33
μ
A approx., and when R
21
=
500
K
Ω
R
21
=
6
.
6
μ
A approx.)
If you do not use battery backup function, input RTCV
DD
to #STBY.
GPIO(P43)
RTC
OSC1
IVRAM
#STBY
R21
(10k )
S1C17801
Fig. A.
2
#STBY Related Circuit
A.
2
Measuring AV
DD
Current Consumption
Current consumed by the power supply for ADC (AV
DD
) can be measured by inserting an ammeter into JP
5
.
Note that sample software (software flow) for measuring the current consumption, the software referred in the
S
1
C
17801
Current Consumption Measurement Application Note does not control the AV
DD
line.
A.
3
Measuring RTCV
DD
Current Consumption
Current consumed by the power supply for IVRAM and RTC inside battery backup area (RTCV
DD
) can be
measured by inserting an ammeter into JP
2
.
When JP
2
is measured between
2
-
3
pins, the voltage becomes
3
.
3
V because RTCV
DD
is supplied from V
DD
generated by regulator. When JP
2
is measured between
1
-
2
pins, on the other hand, the voltage becomes
3
.
0
V
because RTCV
DD
is supplied from coin cell battery.
Note that sample software (software flow) for measuring the current consumption, the software referred in the
S
1
C
17801
Current Consumption Measurement Application Note causes approximately
3
to
4
μ
A current to flow in
the RTCV
DD
line.
Summary of Contents for S5U1C17801T1100
Page 4: ......
