Renesas V850E2 Manuel d'utilisateur télécharger pdf (Page 6)

R01DS0139ED0100

Data Sheet

Notes for CMOS Devices

(1) Precaution against ESD for semiconductors

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 text 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

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 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

specifications governing the devices.

(3) Status before initialization of MOS devices

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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Renesas V850E2 Manuel d'utilisateur Page 6