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
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 immediately after power-on for devices
having reset function.
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3
FIP, IEBus, Inter Equipment Bus, and EEPROM are trademarks of NEC Corporation.
MS-DOS, Windows, and Windows NT are either trademarks or registered trademarks of Microsoft Corporation
in the United States and/or other countries.
PC/AT is a trademark of International Business Machines Corporation.
SPARCstation is a trademark of SPARC International, Inc.
Solaris and SunOS are trademarks of Sun Microsystems, Inc.
HP9000 Series 700 and HP-UX are trademarks of Hewlett-Packard Company.
NEWS and NEWS-OS are trademarks of Sony Corporation.
Ethernet is a trademark of Xerox Corporation.
OSF/Motif is a trademark of Open Software Foundation, Inc.
TRON is an abbreviation of The Realtime Operating system Nucleus.
ITRON is an abbreviation of Industrial TRON.
4
Preliminary User’s Manual U13987EJ1V0UM00
The export of these products from Japan is regulated by the Japanese government. The export of some or all of these
products may be prohibited without governmental license. To export or re-export some or all of these products from a
country other than Japan may also be prohibited without a license from that country. Please call an NEC sales
representative.
License not needed:
µ
PD78F4938
The customer must judge the need for license:
µ
PD784935, 784936, 784937, 784938
The application circuits and their parameters are for reference only and are not intended for use in actual design-ins.
•
The information contained in this document is being issued in advance of the production cycle for the
device. The parameters for the device may change before final production or NEC Corporation, at its own
discretion, may withdraw the device prior to its production.
•
Not all devices/types available in every country. Please check with local NEC representative for availability
and additional information.
•
No part of this document may be copied or reproduced in any form or by any means without the prior written
consent of NEC Corporation. NEC Corporation assumes no responsibility for any errors which may appear in
this document.
•
NEC Corporation does not assume any liability for infringement of patents, copyrights or other intellectual property
rights of third parties by or arising from use of a device described herein or any other liability arising from use
of such device. No license, either express, implied or otherwise, is granted under any patents, copyrights or other
intellectual property rights of NEC Corporation or others.
•
Descriptions of circuits, software, and other related information in this document are provided for illustrative
purposes in semiconductor product operation and application examples. The incorporation of these circuits,
software, and information in the design of the customer's equipment shall be done under the full responsibility
of the customer. NEC Corporation assumes no responsibility for any losses incurred by the customer or third
parties arising from the use of these circuits, software, and information.
•
While NEC Corporation has been making continuous effort to enhance the reliability of its semiconductor devices,
the possibility of defects cannot be eliminated entirely. To minimize risks of damage or injury to persons or
property arising from a defect in an NEC semiconductor device, customers must incorporate sufficient safety
measures in its design, such as redundancy, fire-containment, and anti-failure features.
•
NEC devices are classified into the following three quality grades:
"Standard", "Special", and "Specific". The Specific quality grade applies only to devices developed based on a
customer designated "quality assurance program" for a specific application. The recommended applications of
a device depend on its quality grade, as indicated below. Customers must check the quality grade of each device
before using it in a particular application.
Standard: Computers, office equipment, communications equipment, test and measurement equipment,
audio and visual equipment, home electronic appliances, machine tools, personal electronic
equipment and industrial robots
Special: Transportation equipment (automobiles, trains, ships, etc.), traffic control systems, anti-disaster
systems, anti-crime systems, safety equipment and medical equipment (not specifically designed
for life support)
Specific: Aircraft, aerospace equipment, submersible repeaters, nuclear reactor control systems, life
support systems or medical equipment for life support, etc.
The quality grade of NEC devices is "Standard" unless otherwise specified in NEC's Data Sheets or Data Books.
If customers intend to use NEC devices for applications other than those specified for Standard quality grade,
they should contact an NEC sales representative in advance.
M5D 98. 12
Preliminary User’s Manual U13987EJ1V0UM00
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