OKI Semiconductor
ML9226
GENERAL DESCRIPTION
FEDL9226-01
Issue Date: Dec. 11, 2002
32-Bit Duplex/Triplex VFD Controller/Driver with Digital Dimming, ADC and Keyscan
The ML9226 is a full CMOS controller/driver for Duplex or Triplex vacuum fluorescent display tube. It conststs
of 32-segment driver outputs and 3-grid pre-driver outputs, so that it can drive directly up to 96-segment VFD.
ML9226 features a digital dimming function, a 8-ch ADC, a 5
×
5 keyscan circuit and an encoder type switch
interface.
ML9226 provides an interface with a microcontroller only by four signal lines: DATA I/O, CLOCK, CS.
FEATURES
•
Supply voltage (V
DISP
)
•
Duplex/Triplex selectable
•
Applicable VFD tube
•
•
•
•
•
•
•
•
•
: 8 to 18.5V (Built-in 5V regulator for logic)
: 2 Grids
×
32 Anodes VFD tube
: 3 Grids
×
32 Anodes VFD tube
32-segment driver outputs
: I
OH
= –5 mA at V
OH
= V
DISP
– 0.8 V (SEG1 to 22)
I
OH
= –10 mA at V
OH
= V
DISP
– 0.8 V (SEG23 to 32)
I
OL
= 500 uA at V
OL
= 2.0 V (SEG1 to 32)
3-grid pre-driver outputs
: I
OH
= – 5.0 mA at V
OH
= V
DISP
– 0.8V
I
OL
= 10 mA at V
OL
= 2.0V
Built-in digital dimming circuit (10-bit resolution)
Built-in 8-ch A/D converter
Built-in 5
×
5 keyscan circuit
3 interface circuits for an encoder type rotary switch
Built-in oscillation circuit (external R and C)
Built-in Power-On-Reset circuit
Package:
80-pin plastic QFP (QFP80-P-1420-0.80-BK) ( ML9226GA)
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FEDL9226-01
OKI Semiconductor
ML9226
PIN DESCRIPTIONS
Pin
1, 64
10
33
30
41
50 to 63,
65 to 67,
69 to 71,
73, 74
75, 76,
78 to 80,
2 to 6
7, 8, 9
36
GRID1
to
3
CS
O
I
SEG23 to 32
O
Symbol
V
DISP
D-GND
L-GND
V
CC
V
REG
Type
—
—
—
O
O
Power supply pins.
Pin1 and pin64 should be connected externally.
D-GND is ground pin for the VFD driver circuit. L-GND is ground pin for
the logic circuit. Pins 10 and 33 should be connected externally.
5 V output pin for internal logic portion and external logic circuit.
Reference voltage (5 V) output pin for A/D converter.
Segment (anode) signal output pins for a VFD tube.
SEG1 to 22
O
These pins can be directly connected to the VFD tube. External circuit is
not required. I
OH
≤
–5 mA
Segment (anode) signal output pins for a VFD tube.
These pins can be directly connected to the VFD tube. External circuit is
not required. I
OH
≤
–10 mA
Inverted Grid signal output pins.
For pre-driver, the external circuit is requiend. I
OL
≤
10 mA
Chip Select input pin.
Data input/output operation is valid when this pin is set at a High level.
Serial clock input pin.
35
CLOCK
I
Data is input and/or output through the DATA I/O pin at the rising edge of
the serial clock.
Serial data input/output pin.
34
DATA I/O
I/O
Data is input to/comes out from the shift register at the rising edge of the
serial clock.
Interrupt signal output to microcontroller. When any key of key matrix is
pressed or released, key scanning is started. After the completion of the
one cycle, this pin goes to high level and keeps the high level until
keyscan stop mode is selected.
Duplex/Triplex operation select input pin.
29
42 to 49
21 to 26
DUP/TRI
CH1 to 8
A1 to A3
B1 to B3
COL1
to
5
I
I
I
Duplex (1/2 duty) operation is selected when this pin is set at a V
CC
level.
Triplex (1/3 duty) operation is selected when this pin is set at a GND level.
Analog voltage input pin for the 8-bit A/D converter.
Input pin for the encoder type rotary switch. The phase of an An/Bn input
is detected.
Return inputs from the key matrix.
16 to 20
I
These pins are active low. When key matrix are in the inactive sate, these
pins are at high level through the internal pull-up resistors. All the inputs
do not have the cahttering absorption function for the keyscans.
Key switch scanning outputs.
11 to 15
ROW1 to 5
O
Normally low level is output through these pin. When any switch of key
matrix is depressed or released, key scanning is started and is continued
until keyscan stop mode is selected. When keyscan stop mode is
selected, all outputs of ROW1 to 5 go back to low level.
Description
27
INT
O
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FEDL9226-01
OKI Semiconductor
ML9226
Pin
40
38, 39
Symbol
DIM OUT
SYNC OUT 1, 2
Type
O
O
Dimming pulse output.
Description
Connect this pin to the slave side DIM IN pin.
Synchronous signal input.
Connect these pins to the SYNC IN1 and SYNC IN2 pins of a slave side.
RC oscillator connecting pins.
Oscillation frequency depends on display tubes to
be used.
For details refer to ELECTRICAL
CHARACTERISTICS.
V
CC
OSC0
R
Co
31
OSC0
I/O
28,32,
37,68,
72,77
NC
-
OPEN pins.
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