
S1C63653 TECHNICAL MANUAL
EPSON
109
CHAPTER 5: SUMMARY OF NOTES
<R/f Converter>
● The power supply terminals for the analog system should be connected as shown below even if the
R/f converter is not used.
VDDA
→ VDD
VSSA
→ VSS
<Arrangement of Signal Lines>
● In order to prevent generation of electromagnetic induction noise caused by mutual inductance, do
not arrange a large current signal line near the circuits that are sensitive to noise such as the oscillation
unit and analog input unit.
● When a signal line is parallel with a high-speed line in long distance
or intersects a high-speed line, noise may generated by mutual
interference between the signals and it may cause a malfunction.
Do not arrange a high-speed signal line especially near circuits that
are sensitive to noise such as the oscillation unit and analog input unit.
<Output Terminals>
● When an output terminal is used to drive an external
component that consumes a large amount of current, the
operation of the external component affects the built-in
power supply circuit of this IC and the output voltage may
vary. When driving a bipolar transistor by a periodic signal
such as the BZ or timer output in particular, it may cause
variations in the voltage output from the LCD system
voltage circuit that affects the contrast of the LCD display.
To prevent this, separate the traces on the printed circuit
board. Put one between the power supply and the IC's VDD
and VSS terminals, and another between the power supply
and the external component that consumes the large
amount of current. Furthermore, use an external compo-
nent with as low a current consumption as possible.
<Precautions for Visible Radiation (when bare chip is mounted)>
● Visible radiation causes semiconductor devices to change the electrical characteristics. It may cause
this IC to malfunction. When developing products which use this IC, consider the following precau-
tions to prevent malfunctions caused by visible radiations.
(1) Design the product and implement the IC on the board so that it is shielded from visible radiation
in actual use.
(2) The inspection process of the product needs an environment that shields the IC from visible
radiation.
(3) As well as the face of the IC, shield the back and side too.
OSC4
OSC3
VSS
Large current signal line
High-speed signal line
Prohibited pattern example
VDD
VSS
Piezo
BZ
CP
Example: Buzzer output circuit
+