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G
Power pins
• When the device is provided with multiple V
potential are internally connected to them to prevent malfunctions such as latch-up. However, be sure to
connect all of the potentially equal pins to the power supply and ground outside the device to reduce
unwanted radiation, prevent the strobe signal from malfunctioning due to a rise of ground level, and to
follow the standards of total output current.
• The power pins should be connected to V
impedance from the current supply source.
• It is best to connect an approximately 0.1µF capacitor between V
the pins of the MB90895 series device.
G
Crystal oscillator circuit
• Noise near the X0 and X1 pins may cause MB90895 series to malfunction. When designing a PC board
using the device, place the X0 and X1 pins, the crystal (or ceramic) oscillator, and the bypass capacitor
leading to the ground as close to one another as possible and prevent the wiring patterns for the X0 and
X1 pins from crossing.
• For stable operation, the PC board is recommended to have the artwork with the X0 and X1 pins
enclosed by a ground line.
G
Procedure of A/D converter/analog input power-on
• Always apply power to the A/D converter power and the analog input (AN0 to AN7 pins) after or
concurrently with the digital power (V
• Always turn off the A/D converter power and the analog input before or concurrently with the digital
power-down.
• Note that AVR should not exceed AV
simultaneously turned on or off with no problem.)
G
Handling pins when not using A/D converter
When not using the A/D converter, the pins should be connected so that AV
V
.
SS
G
Precautions at power on
To prevent a malfunction of the internal step-down circuit, the voltage rise time at power-on should be
50µs or more (between 0.2 V and 2.7 V).
G
Stabilization of supply voltage
A sudden change in the supply voltage may cause the device to malfunction even within the specified V
supply voltage operating range. Therefore, the V
For stabilization reference, the supply voltage should be controlled so that V
peak values) at commercial frequencies (50 to 60 Hz) fall below 10% of the standard V
and the transient regulation does not exceed 0.1 V/ms.
pins and V
CC
SS
and V
of MB90895 series device at the lowest possible
CC
SS
)-on.
CC
at turn on or off. (The analog power and digital power can be
CC
supply voltage should be stabilized.
CC
CHAPTER 2 HANDLING DEVICES
pins, the pins designed to have equal
and V
as a bypass capacitor near
CC
SS
= AVR = V
CC
CC
ripple variations (peak-to-
CC
supply voltage
CC
and AV
=
SS
CC
17
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