UPD75402ACT datasheet(46/48 Pages) NEC

46 / 48 page

µPD75402A(A)

Cautions on CMOS Devices

Countermeasures against static electricity for all MOSs

Caution

When handling MOS devices, take care so that they are not electrostatically charged.

Strong static electricity may cause dielectric breakdown in gates. When transporting

or storing MOS devices, use conductive trays, magazine cases, shock absorbers, or

metal cases that NEC uses for packaging and shipping. Be sure to ground MOS

devices during assembling. Do not allow MOS devices to stand on plastic plates or

do not touch pins.

Also handle boards on which MOS devices are mounted in the same way.

CMOS-specific handling of unused input pins

Caution

Hold CMOS devices at a fixed input level.

Unlike bipolar or NMOS devices, if a CMOS device is operated with no input, an

intermediate-level input may be caused by noise. This allows current to flow in the

CMOS device, resulting in a malfunction. Use a pull-up or pull-down resistor to hold

a fixed input level. Since unused pins may function as output pins at unexpected

times, each unused pin should be separately connected to the VDD or GND pin

through a resistor.

If handling of unused pins is documented, follow the instructions in the document.

Statuses of all MOS devices at initialization

Caution

The initial status of a MOS device is unpredictable when power is turned on.

Since characteristics of a MOS device are determined by the amount of ions im-

planted in molecules, the initial status cannot be determined in the manufacture

process. NEC has no responsibility for the output statuses of pins, input and output

settings, and the contents of registers at power on. However, NEC assures operation

after reset and items for mode setting if they are defined.

When you turn on a device having a reset function, be sure to reset the device first.

UPD75402ACT 데이터시트(PDF) 46 Page - NEC