19

µPD6222

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 MOS DEVICES

Note: No connection for MOS 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. MOS

device behaves differently than Bipolar device. Input levels of MOS device

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 specifica-

tions governing the devices.

3

STATUS BEFORE INITIALIZATION OF MOS DEVICES

Note: Power-on does not necessarily define initial status of MOS device. Produc-

tion 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.