rs5c62 RICOH Co.,Ltd., rs5c62 Datasheet - Page 40

• Manufacturer Part Number: rs5c62
• Description: Real-time Clock
• Manufacturer: RICOH Co.,Ltd.

36
RP/RF/RS5C62
Category
Answer 4: Because the oscillatory circuit is driven by a constant voltage of 2V relative to the VDD pin,
Answer 5: To reduce power consumption, the oscillatory circuit is driven by a constant voltage of about 2V
Question 4 : Why should you avoid connecting either end of the oscillatory capacitors C
VSS pin instead of the VDD pin?
Question 5 : Synchroscopic observation of the OSCOUT pin output shows that it has an oscillatory
waveform having a small amplitude or approximating to the VDD pin input. What is the cause of this
phenomenon?
either one end of the oscillatory capacitors C
out exception. When either one end of the oscillatory capacitors C
VSS pin instead of the VDD pin, the oscillatory circuit is still operational but subject directly to
fluctuations in the voltage of the system power supply. Under sharp fluctuations between 5V
and battery voltage in particular, the oscillatory circuit may be brought to a temporary stop.
Thus, it is not recommendable to connect either one end of the oscillatory capacitors C
C
relative to the VDD pin, so that the OSCOUT pin output has an oscillatory waveform shown in
the figure below. Its amplitude will vary slightly depending on the capacitance of the oscillatory
capacitor C
directly applied to adjustment of oscillation frequencies, which are shifted by use of a probe.
(For how to adjust oscillation frequencies, see “4. Adjustment of Oscillation Frequencies” in
“USAGE”.)
–10
ppm
–5
10
D
Sample Measurements of Variations in Oscillation Characteristics of ICs
5
0
to the VSS pin.
0
LOT1
V
V
D
DD
SS
. Note that the oscillatory waveform measurements on the OSCOUT pin cannot be
5
LOT2
Internal constant voltage output
10
Number of samples
LOT3
15
Questions and Answers
LOT4
V
C
Total of 54 ICs sampled from 6 lots for measurement
Average variation: 0ppm
Standard deviation: 0.630ppm
DD
G
20
: Approx. 10.5pF, C
: 5V at room temperature
G
LOT5
and C
Vp-p:Approx.
25
D
1.5 to 2.0V
must be connected to the VDD pin with-
LOT6
30
D
: Approx. 12.5pF
Approx.
G
2.0V
and C
D
is connected to the
G
and C
D
to the
G
and