64
µ
PD754202, 754202(A)
NOTES FOR CMOS DEVICES
1
PRECAUTION AGAINST ESD FOR SEMICONDUCTORS
Note: 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 includ-
ing 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
Note: 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
device 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 V
DD
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
Note: 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 immedi-
ately after power-on for devices having reset function.
Содержание Mu754202
Страница 63: ...63 µPD754202 754202 A MEMO ...