FEDL9203-01
1
Semiconductor
ML9203-xx
PIN DESCRIPTION
Pin
1 to 15,
81 to 100
16 to 50
53 to 60,
71 to 78
Symbol
SEGA1 to A35
SEGB1 to B35
COM1 to 16
O
Type
O
Connects to
VFD tube
anode
electrode
VFD tube
grid
electrode
VFD tube
anode
electrode
Power
supply
Micro-
controller
Micro-
controller
Micro-
controller
Description
VFD tube anode electrode drive output.
Directly connected to fluorescent display tube and a pull-
down resistor is not necessary. I
OH
> –5 mA
VFD tube grid electrode drive output.
Directly connected to fluorescent display tube and a pull-
down resistor is not necessary. I
OH
> –50 mA
VFD tube anode electrode drive output.
Directly connected to fluorescent display tube and a pull-
down resistor is not necessary. I
OH
> –20 mA
V
DD
-L-GND are power supplies for internal logic.
V
DISP
-D-GND are power supplies for driving fluorescent
tubes. Apply V
DISP
after V
DD
is applied.
Use the same power supply for L-GND and D-GND.
Serial data input (positive logic).
Input from LSB.
Shift clock input.
Serial data is shifted on the rising edge of
CP.
Chip select input.
Serial data transfer is disabled when
CS
pin is “H” level.
Reset input.
“Low” initializes all the functions.
Initial status is as follows.
• Address of each RAM .............. address “00”H
• Data of each RAM .................... Content is undefined
• Display digit .............................. 16 digits
• Brightness adjustment.............. 0/1024
• All lights ON or OFF ................. OFF mode
Pins for self-oscillation.
(Do not apply external clocks to these pins.)
Connect these pins to the crystal and capacitors or to the
ceramic resonator and capacitors.
The target oscillation frequency is 4.0 MHz.
(Note that the device includes the feed back resistor of
1 MΩ.)
See Application Circuit.
52, 79
69
62
51, 80
61, 70
68
67
66
ADA, ADB
V
DD
L-GND
V
DISP
D-GND
DA
CP
CS
O
—
l
l
l
65
RESET
l
Micro-
controller
63
OSC0
l
Crystal or
ceramic
resonator
64
OSC1
O
4/32
OKI [ OKI ELECTRONIC COMPONETS ]
