SIC63616-(Rev. 1.0) NO. P180
3240-0412
<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 inter-
ference 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.
OSC4
OSC3
V
SS
Large current signal line
High-speed signal line
Prohibited pattern example
<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 volt-
age 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 V
DD
and
V
SS
terminals, and another between the power supply and
the external component that consumes the large amount of
current. Furthermore, use an external component with as
low a current consumption as possible.
V
DD
V
SS
Piezo
BZ
C
P
Example: Buzzer output circuit
+
<Precautions for Visible Radiation (when bare chip is mounted)>
●
Visible radiation causes semiconductor devices to change electrical characteristics. It may cause the IC
to malfunction. When developing products, consider the following precautions to prevent malfunctions
caused by visible radiation.
(1) Design the product and bond the IC on the board so that it is shielded from visible radiation in ac-
tual use.
(2) The inspection process of the product needs an environment that shields the IC from visible radia-
tion.
(3) Shield not only the face of the IC but the back and side as well.
(4) After the shielded package has been opened, the IC chip should be bonded on the board within one
week. If the IC chip must be stored after the package has been opened, be sure to shield the IC from
visible radiation.
(5) If there is a possibility that heat stress exceeding the reflow soldering condition is applied to the IC
in the bonding process, perform enough evaluation of data stored in the nonvolatile memory before
the product is shipped.