AD6312
1/4- to 1/11 Duty VFD Controller/Driver
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev. A4 Dec 29, 2003
1/13
Features
˙4-pin serial interface
˙Key scanning (6×4 matrices)
˙Programming display modes (11-segments & 11-
digits to 16-segments & 6-digits)
˙Programming dimming step
˙High-voltage output (VDD-35V max).
˙4 channels LED ports.
˙4-pin General-purpose input port
˙Built-in oscillator
˙No external resistor necessary for driver outputs
General Description
The AD6312 is a VFD (Vacuum Fluorescent
Display) controller/driver that is driven on a 1/4- to
1/11 duty factor (include key scan). It consists of 5
segment output lines, 6 segment/key scan output
lines, 6 grid output lines, 5 segment/grid output
drive lines, a display memory, a control circuit, and
a key scan circuit. Serial data is input to the
AD6312 through a four-line serial interface.
Pin Assignments
Grid
4
Grid
3
Grid
2
Grid
1
V
DD
LED
4
LED
3
LED
2
LED
1
V
SS
OSC
Seg
8
Seg
7
Seg
6
/ KS
6
V
DD
Key
4
Key
3
VEE
Seg16 / Grid7
Grid6
Grid5
Key2
Key1
STB
CLK
VSS
DIN
DOUT
Sw4
Sw3
Sw2
Sw1
Seg
5
/ KS
5
Seg
4
/ KS
4
Seg
3
/ KS
3
Seg
2
/ KS
2
Seg
1
/ KS
1
Seg15 / Grid8
Seg14 / Grid9
Seg13 / Grid10
Seg12 / Grid11
Seg11
Seg10
Seg9
34
35
36
37
38
39
40
41
42
43
44
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
23
24
25
26
27
28
29
30
31
32
33
Use all power pins.
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
2/13
Pin Descriptions
Symbol Name No. Description
DIN Data input 6
Input serial data at rising edge of shift clock,
starting from the low order bit.
DOUT Data output 5
Output serial data at the falling edge of the shift
clock, starting from low order bit. This is N-ch
open-drain output pin.
STB Strobe 9
Initializes serial interface at the rising or falling
edge of the AD6312. It then waits for reception of
a command. Data input after STB falling is
processed as a command. While command data
is processed, current processing is stopped, and
the serial interface is initialized. While STB is
high, CLK is ignored.
CLK Clock input 8
Reads serial data at the rising edge, and outputs
data at the falling edge.
OSC Oscillator pin 44
Connect resistor in between this pin and Vss to
set up the oscillation frequency.
Seg7 to Seg11 High-voltage output (Segment) 21 to 25 Segment output pins
Seg1/KS1 to
Seg6/KS6 High-voltage output 15 to 20 Multi-function pins, Segment output pins (Dual
function as key scan source)
Grid1 to Grid6 High-voltage output (Grid) 32 to 37 Grid output pins
Seg12/Grid11 to
Seg16/Grid7 High-voltage output (Segment/grid) 26,
28 to 31
These pins are selectable for segment or grid
driving.
LED1 to LED4 LED output 39to 42 CMOS output
KEY1 to KEY4 Key data input 10 to 13 Data input to these pins is latched at the end of
the display cycle.
VDD Logic power 14, 38 Logic power supply
VSS Logic ground 7, 43 Connect this pin to system GND.
VEE Pull-down level 27 Driver power supply
SW1 to SW4 Switch input 1 to 4 These pins constitute a 4-bit general-purpose
input port.
Ordering Information
AD6312 X X X
Packing
Blank : TrayQ: QFP-44L
Package Lead
Blank: Normal
F: Lead Free
L: LQFP-44L
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
3/13
Block Diagram
4-bit
latch
D
IN
D
OUT
CLK
STB
R
V
DD
4
4
V
DD
(+5V)
611
5
5
16 11
5
V
EE
(-30V)
Vss
(0V)
Serial
I/F
4-bit latch
LED
1
LED
4
OSC
SW
1
to
SW
4
KEY
1
to
KEy
4
Command
decoder
Display memory
16 bits
×
11 Words
16-bit
output latch
Timing generator
key scan
Key data memory
(4
×
6)
11-bit shift register
Dimming
circuit
Data selector
Grid driver Segment
driver
Seg6/KS6
Seg7
Seg
12
/Grid
11
Grid
1
Grid
6
Segment/grid
driver
Seg
16
/Grid
7
Key data memory (4x6)
Segment/
key scan
Seg1/KS1
Seg11
5
6
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
4/13
Absolute Maximum Ratings (TA=25oC,VSS=0V )
Parameter Symbol Rating Unit
Logic Supply Voltage VDD -0.5 to +7.0 V
Driver Supply Voltage VEE V
DD +0.5 to VDD -40 V
Logic Input Voltage VI1 -0.5 to VDD +0.5 V
VFD Driver Output Voltage VO2 V
EE-0.5 to VDD +0.5 V
LED Driver Output Current IO1 +15 mA
VFD Driver Output Current IO2 -40 (grid)
-15 (segment) mA
Operating Ambient Temperature TOPT -25 to +85 oC
Storage Temperature TSTG -50 to +125 oC
Operating Conditions (TA=0 to +70 oC,VSS=0V)
Parameter Symbol Conditions Min. Typ. Max. Unit
Logic Supply Voltage VDD 4.5 5 5.5 V
High-Level Input Voltage VIH 0.7·VDD V
DD V
Low-Level Input Voltage VIL 0 0.3·VDD V
Driver Supply Voltage VEE 0 VDD-35 V
DC Characteristics (TA=0 to 70 oC, VDD=4.5 to 5.5V, VSS=0V, VEE=VDD-35V)
Parameter Symbol Conditions Min. Typ. Max. Unit
High-Level Output Voltage VOH1 LED1-LED4, IOH1=-1mA 0.9VDD V
Low-Level Output Voltage VOL1 LED1-LED4, IOL1=12mA 1 V
Low-Level Output Voltage VOL2 D
OUT, IOL2=2mA 0.4 V
High-Level Output Current IOH21 V
O=VDD-2V, Seg1 to Seg11 -3 mA
High-Level Output Current IOH22 VO=VDD-2V, Grid 1 to Grid6
Seg12/Grid11 to Seg16/Grid7 -15 mA
Driver Leakage Current IOLEAK V
O=VDD-35V, driver off -10 μA
Output Pull-Down Resistor RL Driver output 50 100 150
kΩ
High-Level Input Voltage VIH 0.7VDD V
Low-Level Input Voltage VIL 0.3VDD V
AC Characteristics (Ta=0 to +70 oC,VDD=4.5 to 5.5 V, VEE=-30V)
Parameter Symbol Conditions Min. Typ. Max. Unit
Oscillation Frequency fOSC R=51 kΩ 350 500 650 KHZ
Maximum Clock Frequency fmax. Duty=50% 1 MHZ
Clock Pulse Width PWCLK 500 ns
Strobe Pulse Width PWSTB 1 µs
Data Setup Time tSETUP 100 ns
Data Hold Time tHOLD 100 ns
Clock-Strobe Time tCLK-STB CLK↑→STB↑ 1 µs
Wait Time tWAIT CLK↑→CLK↓(Note) 1 µs
Note : Refer to page 8.
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
5/13
Function Descriptions
1.0 Commands
Commands set the display mode and status of the VFD driver. The first 1 byte input to the AD6312 through
the DIN pin after the STB pin has fallen is regarded as a command. If STB is set high while a commands/data
are transmitted, serial communication is initialized, and the commands/data being transmitted are invalid
(however, the commands/data previously transmitted remain valid).
1.1 Display mode setting commands
These commands initialize the AD6312 and select the number of segments and the number of grids (4 grids
& 16 segments to 11 grids & 11 segments to). When these commands are executed, the display is forcibly
turned off, and key scanning is also stopped. To resume display, the display command “ON” must be
executed. If the same mode is selected, however, nothing happens.
LSB
00-- -b2b1b0
MSB
Irrelevant Display mode settings
000: 4 digits, 16 segments
001: 5 digits, 16 segments
010: 6 digits, 16 segments
011: 7 digits, 15 segments
100: 8 digits, 14 segments
101: 9 digits, 13 segments
110: 10 digits, 12 segments
111: 11 digits, 11 segments
On power application, the 11-digit, 11-segment mode is selected.
1.2 Data setting commands
These commands set data write and data read modes. On power application, the normal
operation and address increment modes are set.
0 1 - - b3 b2 b1 b0
Irrelevant
MSB LSB
Data write and read mode settings.
00: Write data to display memory.
01: Write data to LED port.
10: Read key data.
11: Read SW data.
Address increment mode settings (display memory).
0: Incremenets address after data has been written.
1: Fixes address.
Test mode settings
0: Normal operation
1: Test mode
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
6/13
1.3 Address setting commands
These commands set an address of the display memory. If address 16H or higher is set, data is ignored,
until a valid address is set. On power application, the address is set to 00H.
1 1 - b3 b2 b1 b0
MSB LSB
b4
Address (00H-15H)
1.4 Display control commands
10- b3b2b1b0
MSB LSB
-
Irrelevant Dimming quantity settings
000: Sets pulse width to 1/16.
001: Sets pulse width to 2/16.
010: Sets pulse width to 4/16.
011: Sets pulse width to 10/16.
100: Sets pulse width to 11/16.
101: Sets pulse width to 12/16.
110: Sets pulse width to 13/16.
111: Sets pulse width to 14/16.
Tums on/off display.
0: Display off (key scan continues)
1: Display on
On power application, the 1/16-pulse width is set, the display is turned off and key scanning is stopped.
2.0 Display RAM Address and Display Mode
The display RAM stores the data transmitted from an external device to the AD6312 through the serial
interface, and is assigned addresses as follows, in 8 bits unit:
Seg
1 Seg4 Seg
8 Seg
12 Seg
16
00 HL 00 HU 01 HL 01 HU DIG1
02 HL 02 HU 03 HL 03 HU DIG2
04 HL 04 HU 05 HL 05 HU DIG3
06 HL 06 HU 07 HL 07 HU DIG4
08 HL 08 HU 09 HL 09 HU DIG5
0 AHL 0 AHU 0 BHL 0 BHU DIG6
0 CHL 0 CHU 0 DHL 0 DHU DIG7
0 EHL 0 EHU 0 FHL 0 FHU DIG8
10 HL 10 HU 11 HL 11 HU DIG9
12 HL 12 HU 13 HL 13 HU DIG10
14 HL 14 HU 15 HL 15 HU DIG11
b0 b3 b4 b7
XX HL XXHU
Lower 4 bits Higher 4 bits
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
7/13
3.0 LED Port
Data is written to the LED port with the write command, starting from the least port’s least significant bit.
When a bit of this port is 0, the corresponding LED lights; when the bit is 1, the LED turns off. The data of
bits 5 through 8 are ignored. On power application, all LEDs are unlit.
- - - - b3 b2 b1 b0
MSB LSB
Don't care
LED1
LED2
LED3
LED4
4.0 Key Matrix and Key-Input data Storage RAM
The key matrix is made up of a 6×4 matrix, as shown below.
Seg1/KS1
Seg2/KS2
Seg3/KS3
Seg4/KS4
Seg5/KS5
Seg6/KS6
KEY
1
KEY
2
KEY
3
KEY
4
The data of each key is stored as illustrated below, and is read with the read command, starting
from the least significant bit.
KEY1
...
KEY4 KEY1
...
KEY4
Seg
1
/KS
1
Seg
3
/KS
3
Seg
5
/KS
5
Seg
2
/KS
2
Seg
4
/KS
4
Seg
6
/KS
6
b4--------b7b0--------b3
Reading sequence
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
8/13
5.0 SW Data
SW data is read with the read command, starting from the least significant bit. Bits 5 through 8 of
the SW data are 0.
0 0 0 0 b3 b2 b1 b0
MSB LSB
SW1
SW2
SW3
SW4
Timing Diagram
(1) Serial Communication Format
Reception (command/write data)
If data continues
STB
b7b6b2b1b0
D
IN
87321CLK
Transmission (read data)
654321
t
WAIT
87654321
b7b6b5b4b3b2b1b0
b0 b1 b2 b3 b4 b5
STB
D
IN
CLK
D
OUT
Data is read.A data read command is set.
(Note)
Because the DOUT pin is an N-ch, open-drain output pin, be sure to connect an external pull-up resistor to
this pin (1kΩ to 10 kΩ).
Note : When data is read, a wait time tWAIT of 1 μs is necessary since the rising of the eighth clock that has set the command, until the
falling of the first clock that has read the data.
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
9/13
(2) Key Scanning and Display Timing
On cycle of key scanning consists of one frame, and data in a 6×4 matrix is stored in RAM.
1/16
T
DISP
1 frame = T
DISP
×
(n+1)
T
DISP
500
μ
s
SEG Output
Grid1
Grid2
Grid3
Gridn
DIG1 DIG2 DIG3 DIGn
Key scan data
DIG1
123456
≅
Switching characteristic waveforms
fosc
50%
OSC
t
THZ
t
TZH
STB
CLK
D
IN
D
OUT
Sn/Gn 90%
10%
PW
CLK
PW
CLK
t
HOLD
t
SETUP
t
PLZ
PW
STB
t
CLK-STB
t
PZL
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
10/13
Applications
Updating display memory by incrementing address
Command 4Data nCommand 3Command 2Command 1 Data 1D
IN
CLK
STB
Command 1: sets display mode
Command 2: sets data(write data to display memory)
Command 3: sets address
Data 1 to n: transfers display data (22bytes max.)
Command 4: controls display
Updating specific display memory
DataCommand 2Command 2 DataCommand 1D
IN
CLK
STB
Command 1: sets data
Command 2: sets address
Data: display data
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
11/13
Package Information
(1) Package Type: QFP-44L
Dimension in millimeter (mm.)
33 23
22
12
111
44
34
10.0
±
0.5
10.0
±
0.5
13.2
±
0.5
0.15 TYP.
2.7(MAX.)
1.6 TYP.
0.88 TYP.0.8 TYP.0.3 TYP.
13.2
±
0.5
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
12/13
(2) Package Type: LQFP-44L
PIN 1 INDENT
E1
E
D
D1
L1
L
0.25
GAGE PLANE
R0.08 MIN.
DETAIL A
DETAIL A
A
A2
A1
y
be
12
o
(4X)
C
( Top View )
θ
Dimensions In Millimeters Dimensions In Inches
Symbol Min. Nom. Max. Min. Nom. Max.
A - - 1.60 - - 0.063
A1 0.05 0.10 0.15 0.002 0.004 0.006
A2 1.35 1.40 1.45 0.053 0.055 0.057
b 0.30 0.37 0.45 0.012 0.015 0.018
C 0.09 - 0.20 0.004 - 0.008
E 11.50 12.00 12.50 0.453 0.472 0.492
E1 9.50 10.00 10.50 0.374 0.394 0.413
D 11.80 12.00 12.20 0.465 0.472 0.480
D1 9.90 10.00 10.10 0.390 0.394 0.398
e - 0.80 - - 0.031 -
L 0.45 0.60 0.75 0.018 0.024 0.030
L1 - 1.00 - - 0.039 -
θ 0˚ 3.5˚ 7˚ 0˚ 3.5˚ 7˚
y 0.00 - 0.08 0.000 - 0.003
AD6312
1/4- to 1/11 Duty VFD Controller/Driver
Anachip Corp.
www.anachip.com.tw Rev. A4 Dec 29, 2003
13/13
Marking Information
AC
AD6312 X
Part Number
Logo
ID code: internal
Year:
Top view
"02" = 2002
"01" = 2001
XX XX XXX
Nth week: 01~52
Blank: Normal
F: Lead Free Package
QFP44/LQFP44
