View SC6928_140870.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

SC6928(S&CIC0311)
DESCRIPTION
LED Driver IC
SC6928 is an LED Controller driven on a 1/7to 1/8 duty factor. Eleven segment output lines, six grid output lines, 1 segment/grid output lines, one display memory, control circuit , key scan circuit are all incorporated into a single chip to build a highly reliable peripheral device for a single chip microcomputer. Serial data is fed to SC6928 via a four-line serial interface. Housed in a 28-pin SO Package, SC6928 pin assignments and application circuit are optimized for easy PCB Layout and cost saving advantages.
www..com
FEATURES
CMOS Technology Low Power Consumption Multiple Display Modes Key Scanning 8-Step Dimming Circuitry Serial Interface for Clock, Data Input, Data Output, Strobe Pins Available in 28-Pin, SOP Package
APPLICATION
Micro-computer Peripheral Device VCR set Combi set
BLOCK DIAGRAM
Control Serial DI/O CLK STB Data Interface Dispaly Memory SEGMENT DRIVER/ KEY SCAN OUTPUT/ OSC OSC Timing Generator GRID DRIVER
R Key Matrix Memory GND
SG1/KS1 SG2/KS2 SG3/KS3 SG4/KS4 SG5/KS5 SG6/KS6 SG7/KS7 SG8/KS8 SG9/KS9 SG10/KS10 SG12/GR7 SG13/GR6 SG14/GR5 GR4 GR3 GR2 GR1
Dimming Circuit
K1
K2
VDD GND
11
SC6928(S&CIC0311)
INPUT/OUTPUT CONFIGURATIONS
LED Driver IC
The schematic diagrams of the input and output circuits of the logic section are shown below. Input Pins: CLK, STB & DIN
VDD
www..com
GND
Input Pins: K1 to K2
VDD
GND
Output Pins: DOUT, GR1 to GR4
VDD
GND
Output Pins: SG1 to SG10
VDD
GND
Output Pins: GR5, GR6 and SG12/GR7
VDD
GND
22
SC6928(S&CIC0311)
PIN CONFIGURATION
LED Driver IC
www..com
OSC DI/O CLK STB K1 K2 VDD SG1/KS1 SG2/KS2 SG3/KS3 SG4/KS4 SG5/KS5 SG6/KS6 SG7/KS7
1 2 3 4 5 6 7 8 9 10 11 12 13 14
28 27 26 25 24 23 22 21 20 19 18 17 16 15
GND GR1 GR2 GND GR3 GR4 GND VDD SG14/GR5 SG13/GR6 SG12/GR7 SG10/KS10 SG9/KS9 SG8/KS8
IC:SC6928
PIN DESCRIPTION
Pin Name OSC DI/O CLK I/O I I/O I Description Oscillator Input Pin A resistor is connected to this pin to determine the oscillation frequency Data Output Pin ( N-Channel, Open-Drain ) or Data Input pin This pin Outputs/Input serial data at the falling(rising) edge of the shift clock. Clock Input Pin This pin reads serial data at the rising edge and outputs data at the falling edge. Serial Interface Strobe Pin The data input after the STB has fallen is processed as a command When this pin is "HIGH", CLK is ignored. Key Data Input Pins. The data sent to these pins are latched at the end of the display cycle. ( Internal Pull-Low Resistor) Ground Pin Segment Output Pins ( p-channel, open drain ) Also acts as the Key Source Segment/Grid Output Pins Power Supply Grid Output Pins Pin No. 1 2 3
STB
I
4
K1 to K2 GND SG1/KS1 to SG10/KS10 SG12/GR7 toSG14/GR5 VDD GR4 to GR1
I O O O
5,6 22,25,28 8~17 18~20 7,21 23,24,26,27
FUNCTIONAL DESCRIPTION
COMMANDS
A command is the first byte ( b0 to b7 ) inputted to SC6928 via the DIN Pin after STB pin has changed from HIGH to LOW Stage. If for some reason the STB Pin is set to HIGH while data or commands are being transmitted, the serial communications is initialized, and the data/commands being transmitted are considered invalid.
33
SC6928(S&CIC0311)
Command 1: Display Mode Setting Commands
LED Driver IC
SC6928 provides 2 display mode settings as shown in the diagram below: As stated earlier a command is the first one byte ( b0 to b7 ) transmitted to SC6928 via the DIN Pin when STB is LOW. However, for these commands, the bit 3 to bit 6 (b2 to b5) are ignored, bit 7 & bit 8 (b6 to b7) are given value of 0. The Display Mode Setting Commands determine the number of segments and grids to be used (12 to 11 segments, 6 to 7 grids). A display command ON must be executed in order to resume display. If the same mode setting is selected, no command execution is take place, therefore, nothing happens. When Power is turned ON, the 7-grid, 11-segment modes is selected. www..com
Command 2: Data Setting Commands
The Data Setting Commands executes the Data Write or Data Read Modes for SC6928. The data Setting Command, the bits 5 and 6 (b4,b5) are ignored, bit 7 (b6) is given the value of 1 while bit 8 (b7) is given the value of 0. Please refer to the diagram below. When power is turned ON, bit 4 to bit 1 (b3 to b0) are given the value of 0.
SC6928 KEYMATRIX & KEYINPUT DATA STORAGE RAM
SC6928 Key Matrix consists of 10 x 2 array as shown below:
K1
K2
SG1/ KS1
SG2/ KS2
SG3/ KS3
SG4/ KS4
SG5/ KS5
SG6/ KS6
SG7/ KS7
SG8/ KS8
SG9/ KS9
SG10/ KS10
Each data entered by each key is stored as follows and read by a READ Command, starting from the last significant bit.
44
SC6928(S&CIC0311)
LED Driver IC
When the most significant bit of the data (b0) has been read, the least significant bit of the next data (b7) is read.
www..com
Command 3: Address Setting Commands
Address Setting Commands are used to set the address of the display memory. The address is considered valid if it has a value of 00H to 0DH. If the address is set to 0EH or higher, the data is ignored until a valid address is set. When power is turned ON, the address is set at at 00H. Please refer to the diagram below.
DISPALYMODE AND RAMADDRESS
Data transmitted from an external device to SC6928 via the serial interface are stored in the Display RAM and are assigned addresses. The RAM addresses of SC6928 are given below in 8 bits unit.
Command 4: Display Control Commands
The Display Control Commands are used to turn ON or OFF a display. It also used to set the pulse width. Please refer to
55
SC6928(S&CIC0311)
LED Driver IC
the diagram below. When the power is turned ON, a 1/16 Pulse width is selected and the displayed is turned OFF (the key scanning is started).
www..com
SCANNING AND DISPLAY TIMING
The key Scanning and Display Timing diagram is given below. One cycle of key scanning consists of 2 frames. The data of the are 10 x 3 matrix is stored in the RAM.
Tdisplay-500us
Key Scan Data
SG Output
DIG1
DIG2
DIG3
DIGn
DIG1
G1
G2
G3
Gn
1 Frame=Tdispaly |O (n+1)
SERIAL COMMUNICATION FROMAT
The following diagram shows the SC6928 serial communication format. The DOUT Pin is an N-channel, opendrain output pin, therefore, it is highly recommended that an external pull-up resistor (1 KOhms to 10 KOhms) must be connected to DOUT. RECEPTION (Data/Command Write)
66
SC6928(S&CIC0311)
STB DIN CLK
b0 b1 b2 b6 b7
LED Driver IC
If data continues
1
2
3
7
8
TRANSMISSION (Data Read)
www..com
STB DIN CLK
DOUT
Data Read Command is set
b0 b1 b2 b3 b4 b5 b6 b7
1
2
3
4
5
6
7
8
twait
1
2
3
4
5
6
b0 b1 b2 b3 b4 b5
Data Reading Starts
where: twait (waiting time) 1s It must be noted that when the data is read, the waiting time (twait ) between the rising of the eighth clock that has set the command and the falling of the first clock that has read the data is greater or equal to 1s.
SWITCHING CHARACTERISTIC WAVEFORM
SC6928 Switching Characteristics Waveform is given below.
fosc 50%
OSC STB
PWSTB
CLK
PWCLK
PWCLK
tCLK-STB
t setup
t hold
DIN
tPZL tPLZ
DOUT
tTZL tTLZ
Gn
90% 10% 90% 10%
Sn
tTZH
tTHZ
where:
PWCLK (Clock Pulse Width) 400nS tsetup (Data Setup Time) 100nS tCLK-STB (Clock-Strobe Time) 1s tTZH(Rise Time) 1s
PWSTB (Strobe Pulse Width) 1s thold (Data Hold Time) 100nS tTHZ(Fall Time)10s tPZL(Propagation Delay Time) 100nS
77
SC6928(S&CIC0311)
LED Driver IC
fosc=Oscillation Frequency tPLZ(Propagation Delay Time) 300uS tTZL< 1s tTLZ<10s Note: Test condition under tTHZ ( Pull low risistor=100k ohms, Loading capacitor =300pf) tTLZ (Pull high risistor =100k ohms, Loading capacitor=300pf )
APPLICATIONS
Display memory www..com is updated by incrementing addresses. Please refer to the following diagram.
STB
CLK
DIN
Command2
Command3
Data1
Data n
Command1
Command4
where: Command 1: Display Mode Setting Command Command 2: Data Setting Command Command 3: Address Setting Command Data 1 to n : Transfer Display Data (14 Bytes max.) Command 4: Display Control Command The following diagram shows the waveforms when updating specific addresses.
STB
CLK
DIN
Command2
Command3
Data
Command 3
Data
where: Command 2 -- Data Setting Command Command 3 -- Address Setting Command Data -- Display Data
88
SC6928(S&CIC0311)
LED Driver IC
RECOMMENDED SOFTWARE PROGRAMMING FLOWCHART
www..com
Note: 1. Command 1: Display Mode Commands 2. Command 2: Data Setting Commands 3. Command 3: Address Setting Commands 4. Command 4: Display Control Commands 5. When IC power is applied for the first time, the contents of the Display RAM is not defined; thus, it is strongly suggested that the contents of the Display RAM must be cleared during the initial setting.
99
SC6928(S&CIC0311)
ABSOLUTE MAXIMUM RATINGS
(Unless otherwise stated, Ta=25, GND=0V) Parameter Supply Voltage Logic Input Voltage Driver Output Current
www..com
LED Driver IC
Symbol VDD VI IOLGR IOHSG ITOTAL Ratings -0.5 to +7 -0.5 to VDD +0.5 +250 -50 400 Unit Volts Volts mA mA mA
Maximum Driver Output Current/Total
RECOMMENDED OPERATING RANGE
(Unless otherwise stated, Ta=-20 to +70, GND=0V) Parameter Logic Supply Voltage Dynamic Current (see Note) High-Level Input Voltage Low-Level Input Voltage Symbol VDD IDDdyn VIH VIL Min. 4.5 0.8VDD 0 Typ. 5 Max. 5.5 10 VDD 0.3VDD Unit V mA V V
Note: Test Condition: Set Display Control Commands = 80H (Display Turn OFF State & under no load)
ELECTRICAL CHARACTERISTICS
(Unless otherwise stated, VDD=5V, GND=0V, Ta=25) Parameter Symbol IOHSG1 High-Level Output Current IOHSG2 Low-Level Output Current Low-Level Output Current Segment High-Level Output Current Tolerance High-Level Input Voltage Low-Level Input Voltage Oscillation Frequency K1 to K2 Pull Down Resistor IOLGR IOLDOUT ITOLSG VIH VIL fosc RKN Test Condition Vo=VDD-2V SG1 to SG10, SG12/GR7 Vo=VDD-3V SG1 to SG12, SG12/GR7 Vo=0.3V GR1 to GR6, SG12/GR7 Vo=0.4V Vo=VDD-3V SG1 to SG10, SG12/GR7 R=33 KOhms K1 to K2 VDD=5V Min. -20 -25 100 4 0.8 VDD 0 350 40 Typ. -25 -30 140 500 Max. -40 -50 5 5 0.3VDD 650 100 Unit mA mA mA mA mA V V KHz KOhms
10 10
SC6928(S&CIC0311)
APPLICATION CIRCUIT
+5V 4148 100uF V+
33K 2.2K 2.2K 2.2K OSC DI/O CLK STB GND GR1 GR2 GND GR3 GR4 GND VDD SG14/GR5 SG13/GR6 SG12/GR7 SG10/KS10 SG9/KS9 SG8/KS8 G5 G6 S12 S10 S9 S8 G3 G4 V+ 0.1uF G1 G2
LED Driver IC
VDD
www..comMCU
VSS
G1 G2 G3 G4 G5 G6
DIGHT1 DIGHT2 DIGHT3 DIGHT4 DIGHT5 DIGHT6
6-GRID X 12-SEGMENTLED (COMMON CATHODE)
K1 K2 V+ S1 S2 S3 S4 S5 S6 S7 VDD SG1/KS1 SG2/KS2 SG3/KS3 SG4/KS4 SG5/KS5 SG6/KS6 SG7/KS7
S10 S9 S8 S7 S6 S5 S4 S3 S2 S1
SEG10 SEG9 SEG8 SEG7 SEG6 SEG5 SEG4 SEG3 SEG2 SEG1
Note: 1I2C 2.2K; 2 MCU SC6928 4148
COMMON CATHODE TYPE LED PANEL:
11 11
KS10 SW19 SW20
KS9 SW17 SW18
KS8 SW15 SW16
KS7 SW13 SW14
KS6 SW11 SW12
KS5 SW9 SW10
KS4 SW7 SW8
KS3 SW5 SW6
KS2 SW3 SW4
KS1 SW1 SW2
SC6928(S&CIC0311)
SEG1 SEG2 SEG3 SEG4 SEG5 SEG6 a b
COM/DIGITAL (GRID)
LED Driver IC
a
c d e f g
d e c h f g b
www..com
SEG7 SEG8
h
Note: 1The capacitor (0.1uF) connected between the GND and the VDD pins must be located as close as possible to the SC6928 chip. 2The SC6928 power supply is separate from the application system power supply.
Pad Assignment ( Chip size:1380um x 1390um )
SG10/ KS10 SG9/ KS9 SG8/ KS8 SG7/ KS7 SG6/ KS6 SG5/ KS5 SG4/ KS4
SG11 SG12/ GR7
SG3/ KS3 SG2/ KS2 SG1/ KS1 VDD K3
GR6 GR5 VDD
ICVSS
GND
K2 K1
GR4
STB CLK
GR3 GR2 GND GR1 GND
OSC DOUT DIN
12 12

▲Up To Search▲

Price & Availability of SC6928

	To Download SC6928 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .