
MB90580C Series
20
It is recommended to provide a bypass capacitor of around 0.1
μ
F between V
CC
and V
SS
pin near the device.
6.
Crystal Oscillator Circuit
Noises around X0 or X1 pins may be possible causes of abnormal operations. Make sure to provide bypass
capacitors via shortest distance from X0, X1 pins, crystal oscillator (or ceramic resonator) and ground lines, and
make sure, to the utmost effort, that lines of oscillation circuit not cross the lines of other circuits.
It is highly recommended to provide a printed circuit board art work surrounding X0 and X1 pins with an grand
area for stabilizing the operation.
Turning-on Sequence of Power Supply to A/D Converter and Analog Inputs
7.
Make sure to turn on the A/D converter power supply (AV
CC
, AV
SS
, AVRH, AVRL) and analog inputs (AN0 to
AN7) after turning-on the digital power supply (V
CC
).
Turn-off the digital power after turning off the A/D converter supply and analog inputs. In this case, make sure
that the voltage of AVRH dose not exceed AV
CC
(turning on/off the analog and digital power supplies simulta-
neously is acceptable).
Connection of Unused Pins of A/D Converter
8.
Connect unused pin of A/D converter to AV
CC
= V
CC
, AV
SS
= AVRH = AVRL = V
SS
.
Connection of Unused Pins of D/A Converter
9.
Connect unused pin of D/A converter to DVRH = V
SS
, DV
SS
= V
SS
.
10. N.C. Pin
The N.C. (internally connected) pin must be opened for use.
11. Notes on Energization
To prevent the internal regulator circuit from malfunctioning, set the voltage rise time during energization at 50
μ
s or more (0.2 V to 2.7 V).
12. Use of the sub-clock
Use the one clock system parts when the sub-clock is not used. Connected the oscillator under 32 kHz to the
both terminals XA0 and X1A for the two clocks system parts. Pull-down the terminal X0A and leave the terminal
X0A open for the one clock system parts.
V
CC
V
SS
V
CC
V
CC
V
CC
V
CC
V
SS
V
SS
V
SS
V
SS
MB90580C
Series