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Notes for CMOS Devices
1. Precaution against ESD for semiconductors
Strong electric field, when exposed to a MOS device, can cause
destruction of the gate oxide and ultimately degrade the device operation.
Steps must be taken to stop generation of static electricity as much as
possible, and quickly dissipate it once, when it has occurred.
Environmental control must be adequate. When it is dry, humidifier should
be used. It is recommended to avoid using insulators that easily build static
electricity. Semiconductor devices must be stored and transported in an
anti-static container, static shielding bag or conductive material. All test
and measurement tools including work bench and floor should be
grounded. The operator should be grounded using wrist strap.
Semiconductor devices must not be touched with bare hands. Similar
precautions need to be taken for PW boards with semiconductor devices
on it.
2. Handling of unused input pins for CMOS
No connection for CMOS device inputs can be cause of malfunction. If no
connection is provided to the input pins, it is possible that an internal input
level may be generated due to noise, etc., hence causing malfunction.
CMOS devices behave differently than Bipolar or NMOS devices. Input
levels of CMOS devices must be fixed high or low by using a pull-up or pull-
down circuitry. Each unused pin should be connected to VDD or GND with
a resistor, if it is considered to have a possibility of being an output pin. All
handling related to the unused pins must be judged device by device and
related specifications governing the devices.
3. Status before initialization of MOS devices
Power-on does not necessarily define initial status of MOS device.
Production process of MOS does not define the initial operation status of
the device. Immediately after the power source is turned ON, the devices
with reset function have not yet been initialized. Hence, power-on does not
guarantee out-pin levels, I/O settings or contents of registers. Device is not
initialized until the reset signal is received. Reset operation must be
executed immediately after power-on for devices having reset function.
User's Manual U18743EE1V2UM00
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