Application Notes - Epson RA8804 CE Applications Manual

RA8804 CE

10. Application notes

1) Notes on handling
This module uses a C-MOS 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 "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 VDD and GNDs). Also, avoid placing any device that generates high level of electronic noise near
this module.
* 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.
(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 VDD or GND.
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.
Therefore, please apply the voltage level close to VDD or GND.
Fig. 1: Reference profile for our evaluation of Soldering heat resistance.
Temperature[C]
300
;+260C 
TP

+255C
250
TL
;+217C
Tsmax
;+200C
200
Tsmin ;+150C
150
100
50
Time +25CtoPeak
0 60 120
Page - 42
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)
180 240 300 360 420 480
tp;at least 30s
Ramp-down rate
-6 °C/s Max.
540 600 660 720 780
Time[s]
ETM60E-02