LD1960 LDT | Alldatasheet
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Technical content
Ver1.0 LD1960
9 SEGMENT X 7 GRID LED Driver with key scan
Ver. 1.0 / Mar. 2009 This document is a general product description and is subject to change without notice. LDT Inc. does NOT assume any responsibility for use of circuits described. LD1960
Ver1.0 LD1960 'JSTU7FSTJPO %BUF$POUFOUT7FSTJPO
Ver1.0 LD1960 The LD1960 is specifically designed for LED and LED DISPLAY drivers. The LD1960 has 9 to 6 segment output lines, 7 to 4 grid output lines, one display memory, control circuit, 4 line serial data interface, and 6 x 2 matrix key scan .Those functions are all incorporated into a single chip to build a highly reliable peripheral device for a single chip microcomputer. It is very convenient to control for numeric display. LD1960’s pin assignments and application circuit are optimized for easy PCB Layout and cost saving advantages.
FEATURES
- CMOS Technology
- Segment output line selection by command : 6 ~ 9
- Grid output line selection by command : 7 ~ 4
- Operation voltage : 5V
- Low Power Consumption
- 8-Step Dimming control by command
- Serial Interface for Clock, Data Input, Strobe Pins, Data output
- 20-pin, TSSOP Package APPLICATION
- Segment LED display : VCR, DVD, MWO
DESCRIPTION
Ver1.0 LD1960 I I I O O O Key scan input pins. This pin is operated with SEG1/KS1 to SEG6/KS6 pins. This pin has Pull down resistor internally. Serial clock input pin. Input data is trigger at rising edge. Output data is trigger at falling edge. When this pin is HIGH, CLK signal is ignored. The data input after the STB has fallen is processed as a command. Power Supply Segment output pins. ( P-channel open drain) Also key scan source pins. Segment / Grid output pin. Segment / Grid output pin. PIN No. 7,8,9,10 11,12 Serial Data Input and N-channel open drain Output Pin. This pin inputs serial data at CLK rising edge. This pin outputs at CLK falling edge. 2DIO I/O K2 I Key scan input pin. This pin is operated with SEG1/KS1 to SEG6/KS6 pins. This pin has Pull down resistor internally. GND - Ground Pin 18 SEG14/GR5 O Segment / Grid output pin. 15 GR4,GR3,GR2,GR1 O Grid output pin 16,17,19,2
Ver1.0 LD1960
Ver1.0 LD1960 INPUT/OUTPUT PINS SCHEMATIC DIAGRAM Input pins : CLK,STB VDD Input pins : K1,K2 VDD Output pins : GR1 to GR4 VDD VDD Output pins : SEG1/KS1 to SEG6/KS6 VDD VDD Output pin : SEG12/GR7, SEG13/GR6, SEG14/GR5 VDD I/O pin : DIO VDD
Ver1.0 LD1960 ABSOLUTE MAXIMUM RATINGS (Unless otherwise stated, Ta=25, GND=0V) PARAMETER Supply Voltage Logic Input Voltage Driver Output Current/Pin Maximum Driver Output Current/Total SYMBOL VDD VI ITOTAL IOHSEG RATING -0.5 to +7.0 -0.5 to VDD+0.5 400 -50 UNIT V V mA mA IOLGR +250 mA 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 0.5VDD TYP. MAX. 5.5 VDD 0.2VDD UNIT V mA V V
- Note : Test Condition : Set Display Control Commands = 80H (Display Turn OFF State) ELECTRICAL CHARACTERISTICS (Unless otherwise stated, VDD=5V, GND=OV, Ta=25, Symbol Test Condition IOHSG1 VO = VDD -2 V SEG1 to SEG6,SEG14/GR5 SEG13/GR6,SEG12/GR7 IOHSG2 VO = VDD -3 V SEG1 to SEG6,SEG14/GR5 SEG13/GR6,SEG12/GR7 IOLGR VO = 0.3V GR1 TO GR4,SEG14/GR5 SEG13/GR6,SEG12/GR7 ITOLSG VO = VDD -3 V SEG1 to SEG6,SEG14/GR5 SEG13/GR6,SEG12/GR7 VIH - VIL - Min. Typ. Max. Unit -20 -25 -40 mA -25 -30 -50 mA 100 140 - mA - - 5 % 0.5VDD - VDD V 0 - 0.2VDD V 350 500 650 kHz Parameter High-Level Output Current Low-Level Output Current Segment High-Level Output Current Tolerance High-Level Input Voltage Low-Level Input Voltage Oscillation Frequency fOSC - IOLDOUT VO = 0.4V DIO 4 - - mALow-Level Output Current 40 - 100 kʃ K1 to K1 Pull Down Resistor KSR VDD=5V
Ver1.0 LD1960 SWITCHING CHARACTERISTIC WAVEFORM LD1960 Switching Characteristics Waveform is given below. PW CLK (Clock Pulse Width) 400ns t setup (Data Setup Time) 100ns t CLK-STB (Clock - Strobe Time) 1ɫ t TZH (Rise Time) 1ɫ t TZL <1ɫ PWSTB (Strobe Pulse Width) 1ɫ thold (Data Hold Time) 100ns t THZ (Fall Time) 10ɫ t TLZ <10ɫ t PZL (Propagation Delay Time) 100ns t PLZ (Propagation Delay Time) 300ns OSC (Internal) STB CLK DIO (Input) GRn SEGn 10% 90% fOSC PWCLK PWCLK tsetup thold PWSTB tCLK-STB 90% 10% tTZL tTZH tTLZ tTHZ DIO (Output) tPZL tPLZ
Ver1.0 LD1960 LD1960 SEG pins Resistor Characteristics is given below. VO (V) IOHSG (mA) 0 1 2 3 4 5 MAX. TYP MIN
Ver1.0 LD1960 The LD1960 has 4 kind of commands. The first command is display setting commands, the second command is data setting command. The third command is address setting command and the fourth command is display control command. COMMAND 1 : DISPLAY MODE SETTING COMMAND The Display mode setting command has 2bit (b1,b0) for display mode setting and 2bit (b7,b6) for commands. And 4bits (b5 ~ b2) are don’t care bit. The command bits (b7,b6) are “0”,”0” for COMMAND1. The display mode setting command determines the number of segments and grids. This command should be executed for display off. And the default of b1,b0 are “1”,”1” for power on. This status is selected 7 grids, 6 segments . If b1,b0 are “1”,”0” then 6 grids 7 segments. If b1,b0 are “0”,”1” then 5 grids 8 segments. If b1,bo are “0”,”0” then 4 grids 9 segments. Don’t Care Display Mode Settings : 00 : 4Grid, 9 Segments 01 : 5Grid, 8 Segments 10 : 6 Grids, 7 Segments 11 : 7 Grids, 6 Segments MSB LSB b6 b5 b4 b3 b2 b1 b0 00 : COMMAND 1
Ver1.0 LD1960 COMMAND 2 : DATA SETTING COMMAND MSB LSB Don’t Care Data Write Mode Settings : 00 : Write data to display mode 01 : Ignore 10 : Read key scan data 11 : Ignore b6 b5 b4 b3 b2 b1 b0 Address Increment Mode Settings (Display Mode): 0 : Increment Address after data has been Written 1 : Fixes Address Mode Settings : 0 : Normal Operation Mode 1 : Test mode ( User don’t use ) The data setting command consists of data write mode setting, address increment mode setting and mode setting . And the default of b3 to b0 are all “0” for power on. The Data write mode settings have 2bit (b1,b0) for writing data to display mode and read key scan data. And address increment mode setting has 1bit (b2) for selecting address Increment or fixed. And mode setting has1bit (b3) for selecting normal operation or test mode. 2bits(b5,b4) are don’t care bits. The command bits (b7,b6) are “0”,”1” for COMMAND2. 01 : COMMAND 2
Ver1.0 LD1960 COMMAND 3 : ADDRESS SETTING COMMAND The display memory is addressed by Address Setting Command. The valid address range is “00H” to 0DH”. If the address is set to 0EH to 0FH, the data is ignored until a valid address is set. When power is turned ON, the address is set at “00H”. MSB LSB Don’t Care b6 b5 b4 b3 b2 b1 b0 Address : 00H to 0DH Display Mode and RAM Address Data transmitted from an external device to LD1960 via the serial interface are stored in the Display RAM and are assigned addresses. The RAM Addresses of LD1960 are given below in 8 bit unit. 00HL 02HL 04HL 06HL 08HL 0AHL 0CHL 04HU 06HU 08HU 0AHU 0CHU 00HU 02HU 05HL 07HL 09HL 0BHL 0DHL 01HL 03HL SEG1 SEG4 SEG5 SEG8 SEG9 SEG12 DIG1 DIG2 DIG3 DIG4 DIG5 DIG6 DIG7 xxHL xxHU b0 b3 b4 b7 Lower 4 bits Higher 4 bits 11 : COMMAND 3 05HU 07HU 09HU 0BHU 0DHU 01HU 03HU SEG13 SEG16
Ver1.0 LD1960 COMMAND 4 : DISPLAY CONTROL COMMANDS The Display Control Commands are used to turn ON or OFF a display. It is also used to set the pulse width. Please refer to the diagram below. When the power is turned ON, a 1/16 pulse width is selected and the display is turned OFF. MSB LSB b6 b5 b4 b3 b2 b1 b0 Don’t Care Dimming Quantity Settings : 000 : Pulse width = 1/16 001 : Pulse width = 2/16 010 : Pulse width = 4/16 011 : Pulse width = 10/16 100 : Pulse width = 11/16 101 : Pulse width = 12/16 110 : Pulse width = 13/16 111 : Pulse width = 14/16 Display Settings : 0 : Display OFF 1 : Display ON 10 : COMMAND 4
Ver1.0 LD1960 T = 500us Key Scan Data
1 FRAME = T x ( n*+1)
*) n is the number of Grid
Ver1.0 LD1960 1) Key Scan Timing The key scan period is 500us at oscillator=500Khz. SEG1/KS1 1 2) Key scan operation
- The key scan is operated always.
- Multiple key presses are recognized by determining whether multiple key data bits are set. SEG2/KS2 2 SEG3/KS3 SEG4/KS4 SEG5/KS5 SEG6/KS6 ℵ ℵ ℵ ℵ ℵ ℵ 1 ℵ ℵ ℵ ℵ ℵ ℵ T = 500us 7T = 3.5ms at 7 grid 6T = 3.0ms at 6 grid 5T = 2.5ms at 5 grid 4T= 2.0ms at 4 grid T = 500us Key scan period Key scan period 3) Key scan data read sequence SEG1/KS1 SEG2/KS2 x 1’st byte read K1 K2 K1 K2 SEG3/KS3 SEG4/KS4 x 2’nd byte read SEG5/KS5 SEG6/KS6 x 3’rd byte read b0 b1 b2 b3 b4 b5 b6 b7 Key press = “1”, Key no press = “0” read. x x x
Ver1.0 LD1960 4) Key Scan Example KS1 KS2 KS3 KS4 KS5 KS6 SW If SW switch is pressed, the K1 of key input pin is high by KS2 at key scan timing. So the K1 pin input is high. SEG1/KS1 1 SEG2/KS2 2 SEG3/KS3 SEG4/KS4 SEG5/KS5 SEG6/KS6 ℵ ℵ ℵ ℵ ℵ ℵ ℵℵ ℵ ℵ ℵ ℵ ℵ ℵ ℵ 1 ℵ DIO pin read data is 00x10xxx 00x00xxx 00x00xxx. x is don’t care.
Ver1.0 LD1960 SERIAL COMMUMICATION FORMAT The following diagram shows the LD1960 serial communication format. RECEPTION (Data/Command Write) STB DIO CLK 1 23 78 If data continues. b0 b1 b2 b6 b7 Transmission (Data Read) STB DIO CLK b0 b1 b2 b3 b4 b5 b6 b7 0 1 0 0 0 0 1 0 b0 b1 b2 b3 b4 b5 b6 b7 b0 b1 b2 b3 b4 b5 b6 K1,K2 -S E G 1 / K S 1 K1,K2 - SEG2/KS2 Don’t Care K1,K2 - SEG3/KS3 K1,K2 - SEG4/KS4 Don’t Care 1’st Byte 2’nd Byte Don’t Care Don’t Care DIO Input DIO Output
Ver1.0 LD1960 SERIAL COMMUNICATION EXAMPLES STB DIO CLK Command1Command2Command3 Data1 Data n Command4 command2 command3 Data command3 Data STB CLK DIO Where : Command 1 : Display Mode Setting 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 Memory updating timing diagram. Where : Command 2 -- Data Setting Command Command 3 -- Address Setting Command Data -- Display Data Serial communication timing diagram for initialization setting.
Ver1.0 LD1960 RECOMMENDED SOFTWARE PROGRAMMING FLOW CHART START SET COMMAND 1 SET COMMAND 2 SET COMMAND 3 Clear Display RAM (see Note 5) SET COMMAND 4 MAIN PROGRAM SET COMMAND 1 SET COMMAND2 SET COMMAND 3 SET COMMAND 4 END
- Note : 1. Command 1 : Display Mode Setting 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 are not defined : thus, it is strongly suggested that the contents of the Display RAM must be cleared during the initial setting. MAIN LOOP INITIAL SETTING
Ver1.0 LD1960 TSSOP 20 THERMAL PERFORMANCE IN STILL AIR Junction Temperature : 1001200 1000 800 600 400 200 -25 0 25 50 75 100 Ambient Temperature, Ta () 966 616 IC Mounted Glass Epoxy PCB IC Single Power Dissipation, Pd (mW)
Ver1.0 LD1960 TYPICAL APPLICATION CIRCUIT SG14/GR5 SEG6/KS6 GR1 GR2 GND GR3 SEG1/KS1 SEG2/KS2 SEG3/KS3 SEG4/KS4 DIO CLK STB VDD MCU SEG6 SEG5 SEG4 SEG3 SEG2 SEG1 DIGIT1 DIGIT2 DIGIT3 DIGIT4 5-GRID X 8-SEGMENT (COMMON CAHODE) +5V 0.1uF GR4 DIGIT5 SEG8 SEG5/KS5 S1 S2 S3 S4 S5 S6 10kʃ SG13/GR6 SG12/GR7 S7 S7 SEG7
Ver1.0 LD1960 a b c d e f g h a b c d e f g h SEG1 SEG2 SEG3 SEG4 SEG5 SEG6 SEG7 SEG8 LED PANEL FOR CATHODE TYPE COM/ DIGITAL(GRID)
Ver1.0 LD1960
PACKAGE INFORMATION
TSSOP 20 Unit : mm