rtc-4553ac Epson Electronics America, Inc., rtc-4553ac Datasheet - Page 26

• Manufacturer Part Number: rtc-4553ac
• Description: Real Time Clock Module
• Manufacturer: Epson Electronics America, Inc.

RTC – 4553AC
11. Application notes
11.1. Notes on handling
11.2. Notes on packaging
Fig. 1: Example GND Pattern
This module uses a C-MOS IC to realize low power consumption. Carefully note the following cautions when
handling.
(1) Static electricity
(2) Noise
(3) Voltage levels of input pins
(4) Handling of unused pins
(1) Soldering temperature conditions
(2) Mounting equipment
(3) Ultrasonic cleaning
(4) Mounting orientation
(5) Leakage between pins
RTC - 4553
While this module has built-in circuitry designed to protect it against electrostatic discharge, the chip could
still be damaged by a large discharge of static electricity. Containers used for packing and transport should
be constructed of conductive materials. In addition, only soldering irons, measurement circuits, and other
such devices which do not leak high voltage should be used with this module, which should also be
grounded when such devices are being used.
If a signal with excessive external noise is applied to the power supply or input pins, the device may
malfunction or "latch up." In order to ensure stable operation, connect a filter capacitor (preferably ceramic)
of greater that 0.1 F as close as possible to the power supply pins ( between V
placing any device that generates high level of electronic noise near this module.
area in a GND land.
When the input pins are at the mid-level, this will cause increased current consumption and a reduced
noise margin, and can impair the functioning of the device. Therefore, try as much as possible to apply the
voltage level close to V
Since the input impedance of the input pins is extremely high, operating the device with these pins in the
open circuit state can lead to unstable voltage level and malfunctions due to noise. Therefore, pull-up or
pull-down resistors should be provided for all unused input pins. ( except L1 L5 pins )
If the temperature within the package exceeds +260 C, the characteristics of the crystal oscillator will be
degraded and it may be damaged. Therefore, always check the mounting temperature before mounting this
device. Also, check again if the mounting conditions are later changed.
While this module can be used with general-purpose mounting equipment, the internal crystal oscillator
may be damaged in some circumstances, depending on the equipment and conditions. Therefore, be sure
to check this. In addition, if the mounting conditions are later changed, the same check should be
performed again.
Depending on the usage conditions, there is a possibility that the crystal oscillator will be damaged by
resonance during ultrasonic cleaning. Since the conditions under which ultrasonic cleaning is carried out
(the type of cleaner, power level, time, state of the inside of the cleaning vessel, etc.) vary widely, this
device is not warranted against damage during ultrasonic cleaning.
This device can be damaged if it is mounted in the wrong orientation. Always confirm the orientation of the
device before mounting.
Leakage between pins may occur if the power is turned on while the device has condensation or dirt on it.
Make sure the device is dry and clean before supplying power to it.
See Fig.2 for the soldering conditions of SMD products.
Do not connect signal lines to the shaded area in the figure shown in Fig.1 and, if possible, embed this
( SOP-14pin )
DD
or GND.
Fig. 2: Soldering Conditions of SMD Products
Air Reflow Profile
Temperature[ C ]
Page - 23
+240 C Max.
+235 C
+200 C
+150 C
90 s
30 s
5 C
10 C
30 s
10 s
DD
and GND ). Also, avoid
10 s
1 s
MQ - 342 - 01
Time[ s ]