MB90570A/570C Series
DS07-13701-9E
17
It is recommended to provide a bypass capacitor of around 0.1
F between VCC and VSS 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 do 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.
Please ask the crystal maker to evaluate the oscillational characteristics of the crystal and this device.
7.
Turning-on Sequence of Power Supply to A/D Converter and Analog Inputs
Make sure to turn on the A/D converter power supply, D/A converter power supply (AVCC, AVRH, AVRL,
DVCC,DVSS) and analog inputs (AN0 to AN7) after turning-on the digital power supply (VCC).
Turn-off the digital power after turning off the A/D converter supply and analog inputs. In this case, make sure
that the voltage does not exceed AVRH or AVCC (turning on/off the analog and digital power supplies simulta-
neously is acceptable).
8.
Connection of Unused Pins of A/D Converter
Connect unused pins of A/D converter to AVCC = VCC, AVSS = AVRH = DVCC = VSS.
9.
N.C. Pins
The N.C. (internally connected) pins must be opened for use.
10. Notes on Energization
To prevent the internal regulator circuit from malfunctioning, set the voltage rise time during energization at 50
or more
s (0.2 V to 2.7 V).
11. Indeterminate outputs from ports 0 and 1
The outputs from ports 0 and 1 become indeterminate during oscillation setting time of step-down circuit (during
a power-on reset) after the power is turned on. (MB90573, MB90V570A)
VCC
VSS
Using power supply pins
MB90570A/570C
series