FEDL9209-01
OKI Semiconductor
ML9209-xx
PIN DESCRIPTION
Pin
28–38,
40–44
Symbol
SEG1–16
Type
O
Connects to
VFD tube
anode
electrode
VFD tube
1–16
COM1–16
O
grid
electrode
26, 27
18, 25
20
17,39
AD1–2
O
VFD tube
anode
electrode
Description
VFD tube anode electrode drive output.
Directly connected to the VFD tube and no pull-down resistor
is required. I
OH
> –6 mA
VFD tube grid electrode drive output.
Directly connected to the VFD tube and no pull-down resistor
is required. I
OH
> –30 mA
VFD tube anode electrode drive output.
Directly connected to the VFD tube and no pull-down resistor
is required. I
OH
> –15 mA
The voltage supply between V
DD
and GND is for the power
supply for the internal logic.
The voltage supply between V
DD
and V
FL
is for the power
supply for driving the VFD tube.
Apply power to V
DD
first, then to V
FL
.
24
23
22
DA
CP
CS
I
I
I
Microcontroller
Microcontroller
Microcontroller
Serial data input pin (positive logic).
Data is input from the LSB.
Shift clock input pin.
Serial data is shifted in on a rising edge of
CP.
Chip select input pin.
Serial data transfer is disabled when
CS
pin is “H” level.
Reset input.
Setting this pin to “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............. 0/16
• All display lights ON or OFF .... OFF mode
• All outputs............................... Low level
Pin for RC oscillation.
Resistors and capacitors are connected externally and
constants vary depending on the V
DD
voltage used.
The target oscillation frequency is 2MHz.
19
OSC0
I/O
C
1
, R
1
OSC0
V
DD
GND
—
V
FL
Power supply
21
RESET
l
Microcontroller
(RC oscillator circuit)
C
1
R
1
*Refer to the Application
Circuit.
4/29
OKI [ OKI ELECTRONIC COMPONETS ]
