Application Notes - Epson RX8804CE Applications Manual

Real time clock module
Hide thumbs Also See for RX8804CE:
Table of Contents

Advertisement

RX8804CE

10.Application Notes

1) Notes on handling
This module uses a CMOS IC to realize low power consumption. Carefully note the following cautions when handling.
(1) Static electricity
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.
(2) Noise
If a signal with excessive external noise is applied to the power supply or input pins, the device may malfunction or "latc h 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
and GND). Also, avoid placing any device that generates high level of electronic noise near this module.
DD
* Do not connect signal lines to the shaded area in the figure shown in Fig. 1 and, if possible, embed this area in a GND land.
(3) Voltage levels of input pins
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, please apply the voltage level close to V
(4) Handling of unused pins
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, please apply the voltage level close to V
But these pins must be the disposals that followed specification of pin exposition when it was specified N.C or open by pin exposition.
2) Notes on packaging
(1) Soldering heat resistance.
If the temperature within the package exceeds +260 C, the characteristics of the crystal oscillator will be degraded, and it may be
damaged. The reflow conditions within our reflow profile is recommended. Therefore, always check the mounting temperature and time
before mounting this device. Also, check again if the mounting conditions are later changed.
* See Fig. 2 profile for our evaluation of Soldering heat resistance for reference.
(2) Mounting equipment
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.
(3) Ultrasonic cleaning
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.
(4) Mounting orientation
This device can be damaged if it is mounted in the wrong orientation. Always confirm the orientation of the device before mounting.
(5) Leakage between pins
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.
Temperature [C]
300
; +260 C
TP
+255 C
250
; +217 C
TL
; +200 C
Ts Max.
200
; +150 C
Ts Min.
150
100
50
Time +25 C to Peak
0
60
120
180
Figure 35 Soldering Profile
OVER
Ramp-up rate
+3
C / s Max.
tL
60 s to 150 s
( +217 C over )
ts
60 s to 120 s
( +150 C to +200 C)
240
300
360
420
480
or GND.
DD
tp ; at least 30 s
Ramp-down rate
-6 C / s Max.
540
600
660
720
780
Time [ s ]
Page - 44
or GND.
DD
ETM59E-05

Advertisement

Table of Contents
loading

Table of Contents