OKI MSC1208

E2C0019-27-Y5
¡ Semiconductor
MSC1208
¡ Semiconductor
This version: Nov.
1997
MSC1208
Previous version: Jul. 1996
23-bit ¥ 2 Duplex Controller/Driver with Digital Dimming and Keyscan Function
GENERAL DESCRIPTION
The MSC1208 is a Bi-CMOS display driver for 1/2-duty vacuum fluorescent display tube.
It consists of 58-bit shift registers, latch circuits, a 10-bit digital dimming circuit, 4 ¥ 4 switch
matrix, and a keyscan circuit for 2-channel, 3-contact rotary switch. With these features, the
MSC1208 not only can display frequencies for audio systems used in automobile applications
and various information, but also can accept keyboard entry. Thus the front panel functions can
be carried out only by this IC.
Since the MSC1208 has the data parity check function and the self-check functions, inspection
at shipment and failure detection can easily be performed.
In addition, since the MSC1208 uses serial interfacing, only two signal lines, DATA ENABLE
and DATA I/O, are used for connection with a microcontroller.
FEATURES
• Power supply voltage
: VDD=8 to 18V (Built-in 5V-regulator for logic)
• Operating temperature range
: –40 to 85°C
• Directly drives 23 segments
: IOH=–8.8mA, Max. at VOH=VDD–0.8V
• Built-in 4 ¥ 4 switch matrix and key scan circuit for 2ch, 3-contact switching
• Built-in digital dimming circuit with 10-bit resolution
• Data parity check function
• Self-check function (segment ON/OFF at intervals of about 1 second in test mode)
• Built-in RC oscillator (capacitor is connected externally)
• Built-in power-on reset circuit
• Package:
42-pin plastic shrink DIP (SDIP42-P-600-1.78) : (Product name : MSC1208SS)
¥¥¥ indicates the code number.
1/14
¡ Semiconductor
MSC1208
BLOCK DIAGRAM
SEG1
VDD
SEG23
Segment Driver
POR
Regulator
GND
Parity
Checker
5V
46Æ23 Segment Control
Parity
Generator
PWMOUT
bit 46 to 24
(Grid2)
L
DATA ENABLE
DATAI/O
46 bit Latch
bit56 to 1
56
2
bit 23 to 1
(Grid1)
56
57 bit56
bit47 bit46
D bit58,
Parity Dimming data
Display data
58 bit Shift Register
C R
bit1
bit56 to 47
10-bit Presetable
Down Counter
SI
C
S
S
4
4
S
S
4
4
GRID2
to PWM OUT
PWM
58-bit Shift Register (26-bit presetable+32-bit¥"1")
S
GRID1
Grid
Pre-driver
Timing Generator
OSC
OSC
out
PE
S
2
8
Parity
Generator
Vreg
TEST
L 4-bit
L 4-bit
4
4
Latch
Latch
Timing
Generator
Row 4 3 2 1
4-bit
4-bit
L Latch
L Latch
4
4
L 3-bit
Latch L 3-bit
Latch
3
Col4 to 7
Rotary
Direction
Checker &
Up/down
Counter
3
Col1 to 3
Detector w/debounce
Col 7 6 5 4 3 2 1
With100kW pull-up resistor
2/14
¡ Semiconductor
MSC1208
PIN CONFIGURATION (TOP VIEW)
SEG18 1
42 VDD
SEG19 2
41 SEG17
SEG20 3
40 SEG16
SEG21 4
39 SEG15
SEG22 5
38 SEG14
SEG23 6
37 SEG13
ROW1 7
36 SEG12
ROW2 8
35 SEG11
ROW3 9
34 SEG10
ROW4 10
33 SEG9
COL1 11
32 SEG8
COL2 12
31 SEG7
COL3 13
30 SEG6
COL4 14
29 SEG5
COL5 15
28 SEG4
COL6 16
27 SEG3
COL7 17
26 SEG2
DATA ENABLE 18
25 SEG1
DATAI/O 19
24 GRID2
GND 20
23 GRID1
OSC 21
22 TEST
42-Pin Plastic Shrink DIP
3/14
¡ Semiconductor
MSC1208
PIN DESCRIPTIONS
Pin
Symbol Type
Description
42
VDD
—
Power Sypply Voltage. A 12V power supply is connected.
20
19
GND
DATA
—
I/O
Ground. 0V is applied.
Serial data input-output.
Enters the input mode when a "H" level signal is input to DATA ENABLE; enters the
output mode when a "L" level signal is input to DATA ENABLE.
18
DATA
ENABLE
I
Serial clock input.
During the "H" level of clock pulse, the input data of the DATA I/O pin (display data or
dimming data) is read, and during the "L" level of clock pulse, the output data (key
swich data) is output to the DATA I/O pin.
11 to 17
COL1 to 7
I
7 to 10
ROW1 to 4
O
Input for the key matrix.
These pins are "L" active. When these keys are in the inactive state, these pins are at
"H" level through the internal pull-up resistors. COL1 to COL3 are for the rotary switch
and COL4 to COL7 are for the push-button switch.
Signal outputs for scanning key matrix.
Normally, ROW1 to ROW4 output a "I" level. Key scanning is executed only once when
a transfer of the rotary switch contact or pressing down or release of the push-button
switch is detected. Key scanning is continued if the rotary switch contact is in the open
state after this one-time scanning. Then, scanning stops when the rotary switch contact
makes connection with any of the selective contacts. After key scanning is stopped,
ROW1 to ROW4 return to a "L" level.
21
OSC
25 to 41, SEG1 to 23
1 to 6
23 , 24
GRID1,2
I/O
O
RC oscillator connection. A capacitor is connected between GND and this pin.
Segment signal output.
O
Inverted GRID signal output. This signal is connected to an external grid driver
(e.g., PNP transistor) input.
I
Input for test. Since this pin has as internal a pull-up resistor, leave this pin open or
pull it up for use. When a "L" level signal is input, all segment outputs go on and off
at intervals of 1 second.
22
TEST
4/14
¡ Semiconductor
MSC1208
ABSOLUTE MAXIMUM RATINGS
Condition
Rating
Unit
Power Supply Voltage
Input Voltage
Parameter
VDD
—
–0.3 to+20
V
VIN
Storage Temperature
TSTG
—
—
–0.3 to+6
–55 to+150
V
°C
PD
Ta=85°C
400
mW
Power Dissipation
Symbol
RECOMENDED OPERATING CONDITIONS
Symbol
Condition
Min.
Typ.
Max.
Unit
Power Supply Voltage
Operating Temperature
Parameter
VDD
Top
—
—
8
–40
—
—
18
85
V
°C
"H" Input Voltage (1)
"H" Input Voltage (2)
VIH1
DATA ENABLE, TEST
3.8
—
5.5
V
VIH2
DATA I/O
4.0
—
5.5
V
"L" Input Voltage (1)
"L" Input Voltage (2)
VIL1
DATA ENABLE, TEST
0
—
0.8
V
VIL2
DATA I/O
0
—
1.2
V
Oscillation Frequency
fOSC
C=68pF
256
512
768
kHz
DATA ENABLE Frequency
fE
Refer to Fig. 1
—
—
1.3
kHz
DATA ENABLE Pulse Width
tW
tRE
Refer to Fig. 1
Refer to Fig. 1
360
—
—
—
—
20
ms
ms
tFE
Refer to Fig. 1
—
—
20
ms
DATA ENABLE Rise Time
DATA ENABLE Fall Time
Data Delay Time
Input Data Valid Time
Output Data Valid Time
Frame Frequency
tX
Refer to Fig. 1
—
—
20
ms
tDV1
Refer to Fig. 1
200
—
—
ms
tDV2
Refer to Fig. 1
150
—
—
ms
fFR
Refer to Fig. 3
—
250
—
Hz
5/14
¡ Semiconductor
MSC1208
ELECTRICAL CHARACTERISTICS
DC Characteristics
(Ta=–40 to+85°C,VDD=8 to 18V)
Parameter
Symbol
Condition
Min.
Max.
Unit
"H" Input Voltage
"H" Input Voltage (2)
VIH1
VIH2
DATA ENABLE, TEST
DATA I/O
3.8
4.0
—
—
V
V
"L" Input Voltage (1)
"L" Input Voltage (2)
VIL1
DATA ENABLE, TEST
—
0.8
V
VIL2
DATA I/O
—
1.2
V
"H" Input Current (1)
"H" Input Current (2)
IIH1
VIN=5V, DATA ENABLE, DATA I/O
–5
5
mA
IIH2
VIN=5V, COL1 to 7, TEST
–30
30
mA
"L" Input Current (1)
IIL1
VIN=0V, DATA ENABLE, DATA I/O
–5
5
mA
"L" Input Current (2)
"H" Output Voltage (1)
IIL2
VIN=0V,COL1 to 7, TEST
–15
–160
mA
VOH1
IOH1=–3mA, SEG1 to 17, VDD=13.8V
13
—
V
"H" Output Voltage (2)
VOH2
IOH2=–8mA, SEG18 to 23, VDD=13.8V
13
—
V
"L" Output Voltage (1)
VOL1
VDD=13.8V, All SEG pins
IOL=500mA
IOL=200mA
IOL=2mA
—
—
—
2
1
0.3
V
V
V
"L" Output Voltage (2)
"L" Output Voltage (3)
VOL2
VDD=13.8V, IOL=10mA, GRID1,2
—
0.8
V
VOL3
—
0.8
V
"L" Output Voltage (4)
VOL4
VDD=13.8V, IOL=200mA, ROW1 to 4
VDD=13.8V, IOL=2mA, DATA I/O
—
1.2
V
Current Consumption
IDD
fosc=512kHz, No Load
—
20
mA
AC Characteristics
(Ta=–40 to+85°C, VDD=8 to 18V)
Parameter
Symbol
Condition
Min.
Max.
Unit
DATA ENABLE Frequency
DATA ENABLE Pulse Width
fE
tW
Refer to Fig. 1
Refer to Fig. 1
—
360
1.3
—
kHz
ms
DATA ENABLE Rise Time
DATA ENABLE Fall Time
tRE
Refer to Fig. 1
—
20
ms
tFE
Refer to Fig. 1
—
20
ms
Data Delay Time
Input Data Valid Time
tX
Refer to Fig. 1
—
20
ms
tDV1
Refer to Fig. 1
200
—
ms
Output Data Valid Time
tDV2
Refer to Fig. 1
150
—
ms
Output Data Active-to-High-Impedance
Time
tHZ
Refer to Fig. 1
—
5
ms
Output Through Rate
(SEG, GRID)
tR
CL=100pF, t=20 to 80%
or 80 to 20% of VDD
—
5
ms
DATA ENABLE Setup Time
tSE
Refer to Fig. 2
300
—
ms
Oscillation Frequency
fOSC
C=68pF
256
768
kHz
Key Scan Characteristics
Parameter
Key Scan Time
Key Scan Width
Symbol
Condition
Min.
Typ.
Max.
Unit
tKS
tSW
Refer to Fig. 4
Refer to Fig. 4
164
41
250
62.5
500
125
ms
ms
6/14
¡ Semiconductor
MSC1208
TIMING DIAGRAM
fE
tw
tRE
tw
tFE
DATA ENABLE
tDV1
DATA I/O
(INPUT)
tx
Hi-z
Hi-z
VALID
VALID
tDV2
tHZ
tx
Hi-z
DATA I/O
(OUTPUT)
VALID
Hi-z
Figure 1. Data Input-Output Timing
8V
VDD
tSE
DATA ENABLE
Figure 2. Power-ON Reset Timing
7/14
¡ Semiconductor
MSC1208
1 Frame
2048-bit time (250Hz typ.)
GRID1
8-bit time
GRID2
1016-bit time max.
3-bit time
SEG1-23
1019-bit time max.
5-bit time
Figure 3. SEG and GRID Output Timing
Note: 1. Shown above is the timing when the duty ratio of digital dimming is 1016/1024.
2. The grid and segment ON time is set by 10-bit digital dimming data.
3. 1-bit time=TOSC(=1/fOSC)=1.95 ms typ.
Key Scan Time
ROW1
Scan pulse width
ROW2
ROW3
ROW4
Figure 4. Key Scan Timing
8/14
¡ Semiconductor
MSC1208
FUNCTIONAL DESCRIPTION
Key Scan
In the case of the push-button switch, key scanning is started only when depression or release
of the key is detected for the purpose of minimizing noise caused by scanning signal. Then, after
completion of 1-cycle scanning, all the ROW outputs return to a "L" level.
The push-button switch input pins (COL4-COL7) are connected to a chattering absorption
circuit that absorbs chattering with the chattering time about 25ms (typ.), so input signals
shorter than 25ms are ignored. Because of this, key scanning is started about 25ms after key
input.
In the case of the rotary switch, key scanning is started only once when a transfer of the rotary
switch contact or pressing down or release of the push-button switch is detected. Key scanning
is continued if the rotary switch contact is in the open state after this one-time scanning. Then,
scanning stops when the rotary switch contact makes connection with any of the selective
contacts. After that, all "L" outputs return to a "L" level.
The rotary switch input pins (COL1-COL3) have an internal chattering absorption circuit that
absorbs chattering with the chattering time about 1ms (typ.), so input signals shorter than 1ms
are ignored. Because of this, key scanning is started about 1ms after a change in switch status.
The switch data is stored in the internal latch circuit, and then transferred to the output register
at the rising edge of the first pulse of DATA ENABLE.
The switch data consists of 16-push button switch data (S1-S16) and 2-rotary switch data (RS1
and RS2). The rotary switch data consists of 3 bits for contact-transfer count and 1-bit for
rotating direction. Since the maximum transfer count is "111" in binary, a transfer is counted up
to seven times. The rotating direction bit is "0" for the regular direction and "1" for the opposite
direction.
[Rotating direction]
Regular direction : R11ÆR12ÆR13ÆR11
Opposite direction : R13ÆR12ÆR11ÆR13 (See figure below)
ROW1
ROW2
ROW3
ROW4
COL1
COL2
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14
S15
S16
COL4
COL3
COL5
COL6
COL7
Figure 5. Key Matrix
COL1
COL2
COL3
R11
ROW1
R12
R13
Figure 6. Rotary Switch Section (RS1)
9/14
¡ Semiconductor
MSC1208
Digital Dimming
The segment and grid ON time can be controlled in the range of 0/1024 (=0%) to 1016/1024
(=99.2%) duty by 10-bit digital dimming data. (See Figure 3, "SEG and GRID Output Timing.")
Data Transfer
The input data (display data or dimming data) from DATA I/O is read into the internal register
after the DATA ENABLE input level changes from "L" to "H". The output data (key switch data)
is output to the DATA I/O pin after the DATA ENABLE input level changes from "H" to "L".
Using this method, bidirectional serial communication using two signal lines, DATA ENABLE
and DATA I/O, can be made.
The transfer data consists of 58 bits including 2-bit parity bit. Data transfer is completed if no
parity error occurs after the 58-bit data has been transferred to the internal register. If a parity
error occurs, the previously transferred data (display data or dimming data) is remained.
If an abnormality occurs in the DATA ENABLE line and no signal pulse is input for 10ms ±5ms
or more, the data transfer is terminated even if it is in progress. Then, when the next pulse is
input, it is identified as the first pulse.
Diagnositc Function
1. Parity
Bit 57 and bit 58 (PO and PI) of the input data are used for parity check. For the output data,
parity is internally generated to add parity bit to bits 25 and 26.
The parity value is, for both input and output, "P0, P1=1, 1" when a total number of "1"s (or "0"s)
is even, and "P0, P1=0, 0" when it is odd.
2. Default mode
This device enters the default mode if no pulse is input to DATA ENABLE for about 1 second
or if a parity error keeps occurring for about 1 second.
In this mode, at the state of keeping the contents of the dimming data before entering the default
mode, the two segment outputs (SEG1, SEG2) only go ON.
This state is reset if no parity error is detected after the data has been transferred.
3. Self test
When the TEST pin is set to a "L" level, all segment outputs go on and off at intervals of about
1 second. At this time, the duty ratio for both segment and grid outputs becomes the maximum
(99.2%).
Power-On Reset
When power is turned on, this device is initialized by the internal power-on reset circuit. Then,
about 1second after the initialization, the device enters the default mode. At this time, the SEG1
and SEG2 segments go ON with the maximum duty ratio (99.2%). This state is reset if no parity
error is detected after the data has been transferred.
10/14
¡ Semiconductor
MSC1208
Input-Output Configuration
1. Input data (58 bits)
Bit
58 57 56 55 to
48 47 46 45 to
2
1
DATA
P1 P0 10 9
2
1 46 45 to
2
1
PARITY
to
Dimming DATA
First in
Display DATA
[Correspondence between input data (Display data) and SEG, GRID]
Display DATA
1 to 23
24 to 26
SEG NO.
GRID NO.
SEG1 to SEG23
SEG1 to SEG23
GRID2
GRID1
[Correspondence between dimming data and duty]
Dimming DATA
(LSB) 1 2 3 4 5 6 7 8 9 10 (MSB)
0000000000
to
0001111111
to
1111111111
Duty (%)
0
to
99.2
* For dimming data greater than or equal to 0001111111, the duty is 99.2%.
(LSB)
(MSB)
[Parity]
When the total number of "1"s or "0"s in the display data and dimming data is even,
add "P0, P1=1, 1" to input data, and when it is odd, add "P0, P1=0, 0".
2. Output data (58 bits)
Bit
DATA
58 to 27 26 25 24 to 9
8
7
6
5
4
3
2
1
ALL"1" P1 P0 S16 to S1 Q23 Q22 Q21 D2 Q13 Q12 Q11 D1
ALL"1" PARITY
RS2 DATA
16 SWITCHES
First out
RS1 DATA
[Direction bit (Rotary switch rotating direction)]
D1, D2=Regular direction: 0, Opposite direction: 1
[Contact transfer count (rotary switch)]
Q11(LSB) to 13(MSB), Q21(LSB) to 23(MSB)
[Push-butter switch]
DS1 to S16=Pressing switch down: 1, Release: 0
[Parity]
When the total number of "1"s or "0"s in the key switch data is even, "P0, P1=1, 1" is
added to the output, and when it is odd, "P0, P1=0, 0" is added.
Note: "1" is output to every bit from bit 27 to bit 58.
11/14
¡ Semiconductor
MSC1208
APPLICATION CIRCUITS
Example of a Basic Application Circuit
*(Note)
RS1
RS2
12V
5V
1 2 3 4
1 2 3 45 67
ROW
COL
VDD
GRID1
GND
Microcomputer
12V
DATA I/O
DATA ENABLE
12V
MSC1208
GRID2
TEST
OSC
SEG1
SEG23
1/2-duty VF display tube
Note: Connect a diode between the rotary switch common contact and selective contacts, as
shown in the diagram above.
12/14
¡ Semiconductor
MSC1208
Example of Using a Single Rotary Switch
* (Note)
RS1
12V
5V
1 2 3 4
1 2 3 45 67
ROW
COL
12V
VDD
GRID1
GND
Microcomputer
DATA I/O
DATA ENABLE
12V
MSC1208
GRID2
TEST
OSC
SEG1
SEG23
1/2-duty VF display Tube
Note: When using a sigle rotary switch, connect the ROW that is not used (ROW1 or ROW2)
and one of COL1 to COL3 via a diode.
If no rotary switch is used, connect ROW1 and one of COL1 to COL3 via a diode, and
also connect ROW2 and one of COL1 to COL3 via a diode.
13/14
¡ Semiconductor
MSC1208
PACKAGE DIMENSIONS
(Unit : mm)
SDIP42-P-600-1.78
Package material
Lead frame material
Pin treatment
Solder plate thickness
Package weight (g)
Epoxy resin
42 alloy
Solder plating
5 mm or more
4.52 TYP.
Notes for Mounting the Surface Mount Type Package
The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which
are very susceptible to heat in reflow mounting and humidity absorbed in storage.
Therefore, before you perform reflow mounting, contact Oki’s responsible sales person for the
product name, package name, pin number, package code and desired mounting conditions
(reflow method, temperature and times).
14/14