Fujitsu MB90M405 Hardware Manual page 18

(7) Power pins
When two or more Vcc pins and Vss pins are provided, pins are designed to be at the same electric
potential are internally connected to the device to prevent malfunctions such as latch-up. However, always
connect all same electric potential pins to power and ground outside the device to prevent decrease of
extraneous and radiation the malfunction of the strobe signal due to a ground level rise, and follow the
standards on total output current, etc. Also, consider to connecting the pins to Vcc and Vss of this device at
the lowest possible impedance from the current supply source (It is recommended to connect a bypass
capacitor of about 0.1 µF of the device between Vcc and Vss).
(8) Application sequence for power analog inputs for A/D converter
Apply the digital power (Vcc) first, and then apply the power (AVcc) and analog inputs (AN0 to AN15) for the
A/D converter. Disconnect the power and analog inputs for the A/D converter first, and then disconnect the
digital power (Vcc).
Also, do not allow the input voltage to exceed AVcc even when using a pin shared with an analog input as
an input port (Simultaneous application and disconnection of analog power and digital power is allowed).
(9) Output of high-voltage withstand output pin (circuit type C or D)
When the high-voltage withstand output pin (circuit type is C or D) is used as an ordinary output port, the
port outputs the VKK pin voltage pull-down value at the L level output. In this case, the VKK pin level
voltage is applied to the external circuit, so it is recommended to add a diode clamp circuit as shown in the
figure below.
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MB90M405 F MC-16LX FAMILY HARDWARE MANUAL
Diode clamp circuit
Pout
R
KK
V
KK
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