MB9B500B Datasheet, PDF (51/113 Pages) SPANSION – This document states the current technical specifications regarding

DataSheet
 HANDLING DEVICES
 Power supply pins
In products with multiple VCC and VSS pins, respective pins at the same potential are interconnected
within the device in order to prevent malfunctions such as latch-up. However, all of these pins should be
connected externally to the power supply or ground lines in order to reduce electromagnetic emission levels,
to prevent abnormal operation of strobe signals caused by the rise in the ground level, and to conform to the
total output current rating.
Moreover, connect the current supply source with each Power supply pin and GND pin of this device at low
impedance. It is also advisable that a ceramic capacitor of approximately 0.1 µF be connected as a bypass
capacitor between each Power supply pin and GND pin, between AVCC pin and AVSS pin near this device.
 Stabilizing power supply voltage
A malfunction may occur when the power supply voltage fluctuates rapidly even though the fluctuation is
within the recommended operating conditions of the VCC power supply voltage. As a rule, with voltage
stabilization, suppress the voltage fluctuation so that the fluctuation in VCC ripple (peak-to-peak value) at
the commercial frequency (50 Hz/60 Hz) does not exceed 10% of the VCC value in the recommended
operating conditions, and the transient fluctuation rate does not exceed 0.1 V/μs when there is a momentary
fluctuation on switching the power supply.
 Crystal oscillator circuit
Noise near the X0/X1 and X0A/X1A pins may cause the device to malfunction. Design the printed circuit
board so that X0/X1, X0A/X1A pins, the crystal oscillator (or ceramic oscillator), and the bypass capacitor
to ground are located as close to the device as possible.
It is strongly recommended that the PC board artwork be designed such that the X0/X1 and X0A/X1A pins
are surrounded by ground plane as this is expected to produce stable operation.
Evaluate oscillation of your using crystal oscillator by your mount board.
 Using an external clock
When using an external clock, the clock signal should be input to the X0,X0A pin only and the X1,X1A pin
should be kept open.
・Example of Using an External Clock
Device
X0(X0A)
Open
X1(X1A)
 Handling when using Multi function serial pin as I²C pin
If it is using multi function serial pin as I²C pins, P-ch transistor of digital output is always disable.
However, I²C pins need to keep the electrical characteristic like other pins and not to connect to external I²C
bus system with power OFF.
48
MB9B500B-DS706-00021-3v0-E, December 15, 2014