35

µPD75P218

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

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

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 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

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 immediately after power-on for devices having

reset function.