¡ 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 Connects to
VFD tube
anode
electrode
VFD tube
grid
electrode
VFD tube
anode
electrode
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 "00"H
• Address of each RAM
Content is undefined
• Data of each RAM
16 digits
• Display digit
0/1024
• Brightness adjusment
OFF mode
• All lights ON or OFF
For a circuit when R and C are connected externally,
see Application Circuit.
Pins for oscillation.
Connect crystal and capacitors or ceralock resonator and
capacitors. (Use a built-in feedback resistor.)
Set the target oscillation frequency to 4 MHz.
For an external circuit, see APPLICATION CIRCUIT.
O
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
—
Power
supply
I
I
I
Micro-
controller
Micro-
controller
Micro-
controller
65
RESET
I
Micro-
controller
or
C, R
63
64
OSC0
OSC1
I
O
Crystal or
ceralock
resonator
5/30
OKI [ OKI ELECTRONIC COMPONETS ]
