7480 Datasheet, PDF (54/98 Pages) Bi technologies – 7/8 Diameter 5-Turn Wirewound Precision Potentiometer

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MITSUBISHI MICROCOMPUTERS
7480/7481 GROUP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
Table 9. Recommended operating conditions (cont.)
Symbol
Parameter
Standard values
Unit
Min.
Typ.
Max.
f(CNTR)
Timer input frequency CNTR0 (P40),
CNTR1 (P41) (Note 3)
f(XIN) = 4 MHz
f(XIN) = 8 MHz
1
MHz
2
f(SCLK)
Serial I/O clock input
frequency SCLK (P16)
(Note 3)
Clock synchronous
serial I/O mode
UART mode
f(XIN) = 4 MHz
f(XIN) = 8 MHz
f(XIN) = 4 MHz
f(XIN) = 8 MHz
250
kHz
500
1
MHz
2
f(XIN)
Clock input oscillation frequency (Note 3)
VCC = 2.7 to 4.5 V
VCC = 4.5 to 5.5 V
2.2VCC – 2
MHz
8
Notes 1 : –40 to 85 °C for extended operating temperature range version.
2 : The average output currents IOH(avg) and IOL(avg) are the average values during 100 ms.
3 : The clock input oscillation frequency is at 50 % duty ratio.
4 : When applying a voltage through a resistor as shown in the figure 54, VI > VCC may be accepted if the current is 1 mA or less.
VI
I
Port P4
Fig. 54 Note on use of port P4
Notes on Clamp Diode (7480 Group)
(1) Total input current
The current of port P4 through the clamp diode can be drawn
up to 1.0 mA per port. When a current that cannot be con-
sumed by microcomputer is sent to the clamp diode, this may
raise the power source pin voltage of the microcomputer.
The system power circuit must be designed so that the power
source voltage of the microcomputer may be stabilized within
standard values.
(2) Maximum input voltage
If the input voltage of a signal connected to port P4 is beyond
VCC + 0.3 V, the input waveform should have a delay exceed-
ing 2 µs/V from the moment that this waveform goes over the
voltage.
For using a CR circuit for delay, calculate a proper delay value
by the following expression:
dt ₌
dv
t
0.6 ! VIN
≥ 2 ! 10^–6 (s/V)
where VIN = Maximum input voltage amplitude margin and
t = C ! R.
The clamp diode of the 7480/7481 group is designed for a level
shift of DC signal unlike ordinary switching diodes. Do not apply
sudden stress, such as rush current, directly to the diode.
Notes on Countermeasures for Noise and
Latch-up (7480 Group)
(1) Connect a bypass capacitor (0.1µF) across the VCC pin and
the VSS pin with the shortest possible wiring, using a relatively
thick wire.
(2) Connect a bypass capacitor (0.01 µF) across the VREF pin and
the VSS pin with the shortest possible wiring, using a relatively
thick wire.
(3) In the oscillation circuit, connect across the XIN and XOUT pins
with the shortest possible wiring. Connect the GND and VSS
pins of the oscillation circuit with the shortest possible wiring,
using a relatively thick wire.
(4) In the case of the P33/VPP pin of the built-in programmable
ROM version, connect an approximately 5 kΩ resistor to the
P33/VPP pin the shortest possible in series.
53