AS1115 D a ta s h e e t 64 LEDs, I²C Interfaced LED Driver with Keyscan 1 General Description 2 Key Features The AS1115 is a compact LED driver for 64 single LEDs or 8 digits of 7-segments. The devices can be programmed via an I²C compatible 2-wire interface. ! Every segment can be individually addressed and updated separately. Only one external resistor (RSET) is required to set the current. LED brightness can be controlled by analog or digital means. ! The devices include an integrated BCD code-B/HEX decoder, multiplex scan circuitry, segment and display drivers, and a 64-bit memory. Internal memory stores the shift register settings, eliminating the need for continuous device reprogramming. All outputs of the AS1115 can be configured for key readback. Key-switch status is obtained by polling for up to 64 keys while 16 keys can be used to trigger an interrupt. Additionally the AS1115 offers a diagnostic mode for easy and fast production testing. The AS1115 features a low shutdown current of typically 200nA, and an operational current of typically 350µA. The number of digits can be programmed, the devices can be reset by software, and an external clock is also supported. The device is available in a QSOP-24 and the TQFN(4x4)-24 package. ! ! ! ! ! ! ! ! ! ! ! 3.4MHz I²C-Compatible Interface Individual LED Segment Control Readback for 16 Keys plus Interrupt Open and Shorted LED Error Detection - Global or Individual Error Detection Hexadecimal- or BCD-Code for 7-Segment Displays 200nA Low-Power Shutdown Current (typ; data retained) Digital and Analog Brightness Control Display Blanked on Power-Up Drive Common-Cathode LED Displays Supply Voltage Range: 2.7 to 5.5V Software Reset Optional External Clock Package: - QSOP-24 - TQFN(4x4)-24 3 Applications The AS1115 is ideal for seven-segment or dot matrix user interface displays of set-top boxes, VCRs, DVDplayers, washing machines, micro wave ovens, refrigerators and other white good or personal electronic applications. Figure 1. Typical Application Diagram VDD 2.7 to 5.5V 9.53kΩ ISET SDA SCL µP IRQ SDA DIG0 to DIG7 8 SEGA-DP KEY0-7 8 AS1115 8 SCL KEYA IRQ KEYB GND www.austriamicrosystems.com Revision 1.03 1 - 24 AS1115 Datasheet - P i n o u t 4 Pinout Pin Assignments SEGDP 17 SEGC 16 VDD AS1115 DIG5 5 15 SEGG 14 SEGB Exposed Pad 8 9 10 11 12 ISET SCL 7 KEYB 13 SEGF KEYA DIG6 6 DIG7 KEYB 12 KEYA 11 DIG7 10 SEGD DIG3 2 GND 3 DIG6 9 DIG5 8 DIG4 7 GND 6 DIG3 5 DIG2 4 DIG1 3 DIG0 2 IRQ 18 SEG E DIG4 4 SDA 1 SDA DIG0 24 23 22 21 20 19 DIG2 1 SEGA AS1115 DIG1 13 ISET 14 SCL 15 SEGA 16 SEGF 17 SEGB 18 SEGG 19 VDD 20 SEGC 21 SEG E 22 SEGDP 23 SEGD 24 IRQ Figure 2. Pin Assignments (Top View) Pin Descriptions Table 1. Pin Descriptions Pin Name SDA QSOP-24 TQFN(4x4)-24 1 DIG0:DIG7 2-5, 7-10 GND 6 KEYA 11 KEYB 12 ISET 13 SCL IRQ SEGA:SEGG , SEGDP VDD 14 24 15-18, 20-23 19 - Description Serial-Data I/O. Open drain digital I/O I²C data pin. Digit Drive Lines. Eight digit drive lines that sink current from the display 1, 2, 4, 5, 6, 7, common cathode. Keyscan detection optional, but must be polled by the 23, 24 µProzessor. 3 Ground. Keyscan Input. Keyscan lines for key readback. Can be used for self8 adressing. 9 Keyscan Input. Keyscan lines for key readback. Set Segment Current. Connect to VDD or a reference voltage through RSET to set the peak segment current (see Selecting RSET Resistor 10 Value and Using External Drivers on page 19). 11 Serial-Clock Input. 3.4MHz maximum rate. 21 Interupt Request Output. Open drain pin. Seven Segment and Decimal Point Drive Lines. 8 seven-segment 12-15, 17-20 drives and decimal point drive that source current to the display. 16 Positive Supply Voltage. Connect to +2.7 to +5.5V supply. Exposed Pad. This pin also functions as a heat sink. Solder it to a large Exposed Pad pad or to the circuit-board ground plane to maximize power dissipation. www.austriamicrosystems.com 22 Revision 1.03 2 - 24 AS1115 Datasheet - A b s o l u t e M a x i m u m R a t i n g s 5 Absolute Maximum Ratings Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Section 6 Electrical Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2. Absolute Maximum Ratings Parameter Input Voltage Range Current Min Max Units VDD to GND -0.3 7 V All other pins to GND -0.3 7 or VDD + 0.3 V DIG0:DIG7 Sink Current 500 mA SEGA:SEGG, SEGDP 100 mA 85 % Digital outputs 1000 V All other pins 1000 V Humidity Electrostatic Discharge 5 Latch-Up Immunity ±100 Thermal Resistance ΘJA Norm: MIL 833 E method 3015 EIA/JESD78 88 ºC/W on PCB, QSOP-24 package 30.5 ºC/W on PCB, TQFN(4x4)-24 package -40 +85 ºC Storage Temperature -55 150 ºC www.austriamicrosystems.com Non-condensing mA Ambient Temperature Package Body Temperature Notes +260 Revision 1.03 ºC The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/ JEDEC J-STD-020D “Moisture/ Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). 3 - 24 AS1115 Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s 6 Electrical Characteristics VDD = 2.7 to 5.5V, RSET = 9.53kΩ, TAMB = -40 to +85°C, typ. values @ TAMB = +25ºC, VDD = 5.0V (unless otherwise specified). Table 3. Electrical Characteristics Symbol Parameter Conditions Min VDD Operating Supply Voltage IDDSD Shutdown Supply Current IDD Operating Supply Current fOSC Display Scan Rate 8 digits scanned 0.48 IDIGIT Digit Drive Sink Current VOUT = 0.65V 320 ISEG Segment Drive Source Current ΔISEG ISEG Segment Drive Current Matching Segment Drive Source Current Typ 2.7 Max Unit 5.5 V µA All digital inputs at VDD or GND, TAMB = +25ºC 0.2 2 RSET = open circuit. 0.35 0.6 All segments and decimal point on; ISEG = -40mA. 335 VDD = 5.0V, VOUT = (VDD -1V) -35 mA 0.96 kHz -47 mA mA -41 3 Average Current % 47 mA Max 1 Unit µA V V V V Table 4. Logic Inputs/Outputs Characteristics Symbol IIH, IIL VIH VIL VOL(SDA) VKEYopen VKEYshort VOL(IRQ) ΔVI Parameter Conditions Input Current SDA, SCL VIN = 0V or VDD Logic High Input Voltage SDA, SCL Logic Low Input Voltage SDA, SCL SDA Output Low Voltage ISINK = 3mA Keyscan Open Input Voltage Min -1 0.7xVDD 0.3xVDD 0.4 0.8xVDD Keyscan Short Input Voltage Interrupt Output Low Voltage ISINK = 3mA Hysteresis Voltage DIN, CLK, LD/CS Capacitive Load for Each Bus Line Short Detection Level Threshold www.austriamicrosystems.com 0.7x VDD 0.4 1 0.7x VDD 0.05x VDD Open Detection Level Threshold Revision 1.03 Typ 400 0.75x VDD 0.1x VDD V V V pF 0.8x VDD 0.15x VDD V V 4 - 24 AS1115 Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s Table 5. Timing Characteristics Symbol fSCL tBUF tHOLDSTART tLOW Parameter SCL Frequency Bus Free Time Between STOP and START Conditions Hold Time for Repeated START Condition SCL Low Period Conditions tSETUPDATA tHOLDDATA Data Hold Time tRISE(SCL) tFALL(SCL) SCL Rise Time SCL Rise Time after Repeated START Condition and After an ACK Bit SCL Fall Time tRISE(SDA) tFALL(SDA) tSETUPSTART Typ 0.1 SCL High Period Setup Time for Repeated START Condition Data Setup Time tHIGH Min Max Unit 3.4 MHz 1.3 µs 160 ns 50 75 ns 50 75 ns 100 ns 10 ns 70 ns 10 40 ns 10 80 ns 10 40 ns SDA Rise Time 20 80 ns SDA Fall Time 20 80 ns tSETUPSTOP STOP Condition Setup Time 160 tRISE(SCL1) tSPIKESUP Pulse Width of Spike Suppressed Key Readback Debounce Time ns 50 ns 20 ms Note: The Min / Max values of the Timing Characteristics are guaranteed by design. Figure 3. Timing Diagram SDI tBUF tHOLDSTART tHIGH tHOLDSTART tR tLOW tSPIKESUP tSETUPDATA tF tSETUPSTOP tSETUPSTART SCL START STOP www.austriamicrosystems.com tHOLDDATA Repeated START Revision 1.03 5 - 24 AS1115 Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s 7 Typical Operating Characteristics RSET = 9.53kΩ, VRset = VDD; Figure 4. Display Scan Rate vs. Supply Voltage; Figure 5. Display Scan Rate vs. Temperature; 800 780 Vdd=2.7V Vdd=4V 780 fosc (Hz) . fosc (Hz) . 760 740 720 Vdd=5V Vdd=5.5V 760 740 720 700 Tamb=-40°C 700 Tamb=+25°C Tamb=+85°C 680 2.7 3.1 3.5 3.9 4.3 4.7 5.1 680 -40 5.5 -15 10 Vdd (V) Figure 6. Segment Current vs. Temperature; Vseg Vseg Vseg Vseg 40 40 Iseg (mA) . Iseg (mA) . 85 50 50 30 20 Vseg Vseg Vseg Vseg 10 = 1.7V; Vdd = 2.7V = 1.7V; Vdd = 5V = 3V; Vdd = 5V = 4V; Vdd = 5V = 4V; Vdd = 5V = 3V; Vdd = 5V = 2V; Vdd = 5V = 1.7V; Vdd = 2.7V 30 20 10 0 -15 10 35 60 0 85 10 20 Tamb (°C) 30 40 50 60 70 80 90 Rset (kOhm) Figure 8. Segment Current vs. Supply Voltage; Figure 9. Segment Current vs. VDD; VRset = 2.8V 50 60 Vseg Vseg Vseg Vseg 45 50 40 = 1.7V = 2V = 2.3V = 3.1V 35 40 Iseg (mA) . Iseg (mA) . 60 Figure 7. Segment Current vs. RSET; 60 0 -40 35 Tamb (°C) 30 20 25 20 15 Vseg = 1.7V 10 Vseg = 3V 10 30 Vseg = 4V 5 0 0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 2.7 Vdd (V) www.austriamicrosystems.com 3 3.3 3.6 3.9 4.2 Vdd (V) Revision 1.03 6 - 24 AS1115 Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s Figure 10. VDIGIT vs. IDIGIT Figure 11. Input High Level vs. Supply Voltage 0.4 3.5 3 2.5 Vih (V) . Vdig (V) . 0.3 0.2 Vdd Vdd Vdd Vdd Vdd 0.1 2 1.5 1 = 2.7V = 3.3V = 4V = 5V = 5.5V 0.5 0 0 0 0.05 0.1 0.15 0.2 0.25 Idig (A) 0.3 2.7 0.35 Figure 12. ISEG vs. VSEG; VDD = 5V 3.5 Rext Rext Rext Rext Rext 45 40 4.3 4.7 5.1 5.5 Vdd (V) 50 = 10k = 13k = 18k = 30k = 56k Rext Rext Rext Rext Rext 45 40 35 = 8k2 = 10k = 13k = 18k = 30k Iseg (mA) . 35 30 30 25 25 20 20 15 15 10 10 5 5 0 0 2 2.5 3 3.5 4 4.5 5 1 1.5 2 Vseg (V) 50 40 3 3.5 4 Figure 15. ISEG vs. VSEG; VDD = 2.7V Rext Rext Rext Rext Rext 45 2.5 Vseg (V) Figure 14. ISEG vs. VSEG; VDD = 3.3V = 6k8 = 8k2 = 10k = 13k = 18k 50 Rext Rext Rext Rext Rext 45 40 = 4k7 = 5k6 = 6k8 = 10k = 13k 35 Iseg (mA) . 35 Iseg (mA) . 3.9 Figure 13. ISEG vs. VSEG; VDD = 4V 50 Iseg (mA) . 3.1 30 30 25 25 20 20 15 15 10 10 5 5 0 0 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 1 Vseg (V) www.austriamicrosystems.com 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 Vseg (V) Revision 1.03 7 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description Block Diagram Figure 16. Block Diagram (QSOP-24 Package) Open/Short Detection VDD + – RSET 19 + Oszillator VDD – 13 VDD ISET 24 8 IRQ SEGA-G, SEGDP Digital Control Logic 8 2-5, 7-10 2 11, 12 DIG0 to DIG7 (PWM, Debounce,....) VDD 15-18, 20-23 KEYA, KEYB VDD 14 SCL 1 I²C Interface Registers 6 GND Data - Registers Control - Registers Scan - Registers SDA AS1115 Figure 17. ESD Structure VDD www.austriamicrosystems.com valid for the pins: - IRQ - SCL - SDA - ISET - SEGA-G, SEGDP - KEYA, KEYB VDD valid for the pins: - DIG0 to DIG7 Revision 1.03 8 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n I²C Interface The AS1115 supports the I²C serial bus and data transmission protocol in high-speed mode at 3.4MHz. The AS1115 operates as a slave on the I²C bus. The bus must be controlled by a master device that generates the serial clock (SCL), controls the bus access, and generates the START and STOP conditions. Connections to the bus are made via the open-drain I/O pins SCL and SDA. Figure 18. I²C Interface Initialisation 1 0 8 0 0 0 0 A1 9 A0 R/W 1 8 D15 D14 D13 D12 D11 D10 D9 9 D8 Default values at power up: A1 = A0 = 0 Figure 19. Bus Protocol MSB SDI ACK from Receiver Slave Address R/W Direction Bit ACK from Receiver 1 SCL 2 6 7 8 9 ACK START 1 2 3-8 8 9 ACK Repeat if More Bytes Transferred STOP or Repeated START The bus protocol (as shown in Figure 19) is defined as: - Data transfer may be initiated only when the bus is not busy. - During data transfer, the data line must remain stable whenever the clock line is HIGH. Changes in the data line while the clock line is HIGH will be interpreted as control signals. The bus conditions are defined as: - Bus Not Busy. Data and clock lines remain HIGH. - Start Data Transfer. A change in the state of the data line, from HIGH to LOW, while the clock is HIGH, defines a START condition. - Stop Data Transfer. A change in the state of the data line, from LOW to HIGH, while the clock line is HIGH, defines the STOP condition. - Data Valid. The state of the data line represents valid data, when, after a START condition, the data line is stable for the duration of the HIGH period of the clock signal. There is one clock pulse per bit of data. Each data transfer is initiated with a START condition and terminated with a STOP condition. The number of data bytes transferred between START and STOP conditions is not limited and is determined by the master device. The information is transferred byte-wise and each receiver acknowledges with a ninth-bit. Within the I²C bus specifications a high-speed mode (3.4MHz clock rate) is defined. - Acknowledge: Each receiving device, when addressed, is obliged to generate an acknowledge after the reception of each byte. The master device must generate an extra clock pulse that is associated with this acknowledge bit. A device that acknowledges must pull down the SDA line during the acknowledge clock pulse in such a way that the SDA line is stable LOW during the HIGH period of the acknowledge clock pulse. Of course, setup and hold times must be taken into account. A master must signal an end of data to the slave by not generating an www.austriamicrosystems.com Revision 1.03 9 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n acknowledge bit on the last byte that has been clocked out of the slave. In this case, the slave must leave the data line HIGH to enable the master to generate the STOP condition. - Figure 19 on page 9 details how data transfer is accomplished on the I²C bus. Depending upon the state of the R/ W bit, two types of data transfer are possible: - Master Transmitter to Slave Receiver. The first byte transmitted by the master is the slave address, followed by a number of data bytes. The slave returns an acknowledge bit after the slave address and each received byte. - Slave Transmitter to Master Receiver. The first byte, the slave address, is transmitted by the master. The slave then returns an acknowledge bit. Next, a number of data bytes are transmitted by the slave to the master. The master returns an acknowledge bit after all received bytes other than the last byte. At the end of the last received byte, a not-acknowledge is returned. The master device generates all of the serial clock pulses and the START and STOP conditions. A transfer is ended with a STOP condition or a repeated START condition. Since a repeated START condition is also the beginning of the next serial transfer, the bus will not be released. The AS1115 can operate in the following slave modes: - Slave Receiver Mode. Serial data and clock are received through SDA and SCL. After each byte is received, an acknowledge bit is transmitted. START and STOP conditions are recognized as the beginning and end of a serial transfer. Address recognition is performed by hardware after reception of the slave address and direction bit. - Slave Transmitter Mode. The first byte (the slave address) is received and handled as in the slave receiver mode. However, in this mode the direction bit will indicate that the transfer direction is reversed. Serial data is transmitted on SDA by the AS1115 while the serial clock is input on SCL. START and STOP conditions are recognized as the beginning and end of a serial transfer. I²C Device Self Addressing If this feature is used, 2 of the 16 key readback nodes can be left open or shorted for self-addressing. This is done with KEYA together with SEGG and SEGF. This two nodes cannot be used for key-readback in this case. After startup all devices have the predefined adress 0000000. A single command for self-addressing will update all connected AS1115. This command has to be done after startup or everytime the AS1115 gets disconnected from the supply. The I²C address definition must be done with fixed connection, since I²C detection is excluded from debounce time of key registers. I²C Device Address Byte The address byte (see Figure 20) is the first byte received following the START condition from the master device. Figure 20. I²C Device Address Byte predefined address: updated address: MSB 6 5 4 3 2 1 LSB 0 0 0 0 0 0 0 R/W MSB 6 5 4 3 2 1 LSB 0 0 0 0 0 A1 A0 R/W - The default slave address is factory-set to 0000000. - The two LSB bits of the address byte are the device select bits, A0 to A1, which can be set by the self-adress command after startup. A maximum of four devices with the same pre-set code can therefore be connected on the same bus at one time. - The last bit of the address byte (R/W) define the operation to be performed. When set to a 1 a read operation is selected; when set to a 0 a write operation is selected. Following the START condition, the AS1115 monitors the I²C bus, checking the device type identifier being transmitted. Upon receiving the address code, and the R/W bit, the slave device outputs an acknowledge signal on the SDA line. www.austriamicrosystems.com Revision 1.03 10 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n Command Byte The AS1115 operation, (see Table 6) is determined by a command byte (see Figure 21 on page 11). Figure 21. Command Byte MSB 6 5 4 3 2 1 LSB D15 D14 D13 D12 D11 D10 D09 D08 Figure 22. Command and Single Data Byte Received From Master to Slave AS1115 Registers From Slave to Master S 0 Slave Address D15 D14 D13 D12 D11 D10 D9 R/W A D8 D7 D6 D5 A Command Byte D4 D3 D2 D1 D0 A Data Byte P 1 Byte Acknowledge from AS1115 Acknowledge from AS1115 0 Acknowledge from AS1115 0 0 Autoincrement Memory Word Address Figure 23. Setting the Pointer to a Address Register to select a Data Register for a Read Operation From Master to Slave AS1115 Registers From Slave to Master S 0 Slave Address D15 D14 D13 D12 D11 D10 D9 R/W A Acknowledge from AS1115 D8 A Command Byte Acknowledge from AS1115 0 P 0 Figure 24. Reading nBytes from AS1115 Autoincrement Memory Word Address From Master to Slave From Slave to Master Acknowledge from AS1115 Acknowledge from Master 0 Stop reading Not Acknowledge from Master 0 1 n Bytes S Slave Address R/W A 1 A First Data Byte D7 D6 D5 D4 D3 D2 D1 AS1115 Registers www.austriamicrosystems.com Revision 1.03 D0 /A Second Data Byte D7 D6 D5 D4 D3 D2 D1 P D0 Autoincrement to next address 11 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n Initial Power-Up On initial power-up, the AS1115 registers are reset to their default values, the display is blanked, and the device goes into shutdown mode. At this time, all registers should be programmed for normal operation. Note: The default settings enable only scanning of one digit; the internal decoder is disabled and the Intensity Control Register (see page 17) is set to the minimum values. Shutdown Mode The AS1115 devices feature a shutdown mode, where they consume only 200nA (typ) current. Shutdown mode is entered via a write to the Shutdown Register (see Table 7). During shutdown mode the Digit-Registers maintain their data. Shutdown mode can either be used as a means to reduce power consumption or for generating a flashing display (repeatedly entering and leaving shutdown mode). For minimum supply current in shutdown mode, logic input should be at GND or VDD (CMOS logic level). When entering or leaving shutdown mode, the Feature Register is reset to its default values (all 0s) when Shutdown Register bit D7 (page 13) = 0. Note: When Shutdown Register bit D7 = 1, the Feature Register is left unchanged when entering or leaving shutdown mode. If the AS1115 is used with an external clock, Shutdown Register bit D7 should be set to 1 when writing to the Shutdown Register. Digit- and Control-Registers The AS1115 devices contain 8 Digit-Registers,11 control-registers and 10 diagnostic-registers, which are listed in Table 6. All registers are selected using a 8-bit address word, and communication is done via the I²C interface. ! Digit Registers – These registers are realized with an on-chip 64-bit memory. Each digit can be controlled directly without rewriting the whole register contents. ! Control Registers – These registers consist of decode mode, display intensity, number of scanned digits, shutdown, display test and features selection registers. Control Register Digit Register Type Table 6. Register Address Map Register Address D7:D0 Page D15:D13 D12 D11 D10 D9 D8 Digit 0 000 0 0 0 0 1 N/A Digit 1 000 0 0 0 1 0 N/A Digit 2 000 0 0 0 1 1 Digit 3 000 0 0 1 0 0 Digit 4 000 0 0 1 0 1 Digit 5 000 0 0 1 1 0 N/A Digit 6 000 0 0 1 1 1 N/A Digit 7 000 0 1 0 0 0 N/A Decode-Mode 000 0 1 0 0 1 (see Table 8 on page 13) 13 Global Intensity 000 0 1 0 1 0 (see Table 17 on page 17) 17 N/A (see Table 9 on page 14, Table 10 on page 14 and Table 11 on page 15) N/A N/A Scan Limit 000 0 1 0 1 1 (see Table 19 on page 17) 17 Shutdown 000 0 1 1 0 0 (see Table 7 on page 13) 12 Self-Adressing 001 0 1 1 0 1 Feature 000 0 1 1 1 0 (see Table 20 on page 18) 18 13 N/A Display Test Mode 000 0 1 1 1 1 (see Table 14 on page 16) DIG0:DIG1 Intensity 000 1 0 0 0 0 (see Table 18 on page 17) DIG2:DIG3 Intensity 000 1 0 0 0 1 (see Table 18 on page 17) DIG4:DIG5 Intensity 000 1 0 0 1 0 (see Table 18 on page 17) DIG6:DIG7 Intensity 000 1 0 0 1 1 (see Table 18 on page 17) www.austriamicrosystems.com Revision 1.03 12 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n Keyscan/Diagnostic Register Type Table 6. Register Address Map Address Register Page D15:D13 D12 D11 D10 D9 D8 Diagnostic Digit 0 000 1 0 1 0 0 N/A Diagnostic Digit 1 000 1 0 1 0 1 N/A Diagnostic Digit 2 000 1 0 1 1 0 N/A Diagnostic Digit 3 000 1 1 0 1 1 N/A Diagnostic Digit 4 000 1 1 0 0 0 N/A Diagnostic Digit 5 000 1 1 0 0 1 N/A Diagnostic Digit 6 000 1 1 0 1 0 N/A Diagnostic Digit 7 000 1 1 0 1 1 N/A KEYA 000 1 1 1 0 0 KEYB 000 1 1 1 0 1 D7:D0 The Shutdown Register controls AS1115 shutdown mode. Table 7. Shutdown Register Format (Address (HEX) = 0x0C)) Mode HEX Code Shutdown Mode, Reset Feature Register to Default Settings Shutdown Mode, Feature Register Unchanged Normal Operation, Reset Feature Register to Default Settings Normal Operation, Feature Register Unchanged Register Data D7 D6 D5 D4 D3 D2 D1 D0 0x00 0 X X X X X X 0 0x80 1 X X X X X X 0 0x01 0 X X X X X X 1 0x81 1 X X X X X X 1 Decode Enable Register (0x09) The Decode Enable Register sets the decode mode. BCD/HEX decoding (either BCD code – characters 0:9, E, H, L, P, and -, or HEX code – characters 0:9 and A:F) is selected by bit D2 (page 18) of the Feature Register. The Decode Enable Register is used to select the decode mode or no-decode for each digit. Each bit in the Decode Enable Register corresponds to its respective display digit (i.e., bit D0 corresponds to digit 0, bit D1 corresponds to digit 1 and so on). Table 9 lists some examples of the possible settings for the Decode Enable Register bits. Note: A logic high enables decoding and a logic low bypasses the decoder altogether. When decode mode is used, the decoder looks only at the lower-nibble (bits D3:D0) of the data in the Digit-Registers, disregarding bits D6:D4. Bit D7 sets the decimal point (SEG DP) independent of the decoder and is positive logic (bit D7 = 1 turns the decimal point on). Table 9 lists the code-B font; Table 10 lists the HEX font. When no-decode mode is selected, data bits D7:D0 of the Digit-Registers correspond to the segment lines of the AS1115. Table 11 shows the 1:1 pairing of each data bit to the appropriate segment line. Table 8. Decode Enable Register Format Examples Decode Mode HEX Code No decode for digits 7:0 Code-B/HEX decode for digit 0. No decode for digits 7:1 Code-B/HEX decode for digit 0:2. No decode for digits 7:3 Code-B/HEX decode for digits 0:5. No decode for digits 7:6 Code-B/HEX decode for digits 0,2,5. No decode for digits 1, 3, 4, 6, 7 0x00 0x01 0x07 0x3F D7 0 0 0 0 D6 0 0 0 0 0x25 0 0 www.austriamicrosystems.com Revision 1.03 Register Data D5 D4 D3 D2 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 1 D1 0 0 1 1 D0 0 1 1 1 0 1 13 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 25. Standard 7-Segment LED Intensity Control and Inter-Digit Blanking A F B G E C D DP Table 9. Code-B Font Register Data Register Data Register Data CharCharCharacter D7 D6:D4 D3 D2 D1 D0 acter D7 D6: D4 D3 D2 D1 D0 acter D7 D6:D4 D3 D2 D1 D0 X 0 0 0 0 X 0 1 1 0 X 1 1 0 0 X 0 0 0 1 X 0 1 1 1 X 1 1 0 1 X 0 0 1 0 X 1 0 0 0 X 1 1 1 0 X 0 0 1 1 X 1 0 0 1 X 1 1 1 1 X 0 1 0 0 X 1 0 1 0 X X X X X X 0 1 0 1 X 1 0 1 1 * 1 * The decimal point can be enabled with every character by setting bit D7 = 1. Table 10. HEX Font Register Data Register Data Register Data CharCharCharacter D7 D6:D4 D3 D2 D1 D0 acter D7 D6: D4 D3 D2 D1 D0 acter D7 D6:D4 D3 D2 D1 D0 * X 0 0 0 0 X 0 1 1 0 X 1 1 0 0 X 0 0 0 1 X 0 1 1 1 X 1 1 0 1 X 0 0 1 0 X 1 0 0 0 X 1 1 1 0 X 0 0 1 1 X 1 0 0 1 X 1 1 1 1 X 0 1 0 0 X 1 0 1 0 X X X X X X 0 1 0 1 X 1 0 1 1 * 1 The decimal point can be enabled with every character by setting bit D7 = 1. www.austriamicrosystems.com Revision 1.03 14 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n Table 11. No-Decode Mode Data Bits and Corresponding Segment Lines Corresponding Segment Line D7 DP D6 A D5 B D4 C D3 D D2 E D1 F D0 G I²C Self Addressing If this feature is used, 2 of the 16 key readback nodes can be left open or shorted for self-addressing. This is done with KEYA together with SEGG and SEGF. This two nodes cannot be used for key-readback in this case. After startup all devices have the predefined adress 0000000. A single command for selfaddressing will update all connected AS1115. This command has to be done after startup or everytime the AS1115 gets disconnected from the supply. The I²C address definition must be done with fixed connection, since I²C detection is excluded from debounce time of key registers. Note: A short writes a logical “1” whereas an open writes a logical “0” as address bit. Table 12. Self Addressing Register (Address (HEX) = 0x2D)) D7 X X Factory-set IC address User-set IC address D6 X X D5 X X D4 X X D3 X X D2 X X D1 X X D0 0 1 Keyscan Register These two registers contain the result of the keyscan input of the 16 keys. To ensure proper results the data in these registers are updated only if the logic data scanned is stable for 20ms (debounce time). A change of the data stored within these two registers is indicated by a logic low on the IRQ pin. The IRQ is high-impedance if a read operation on the key scan registers is started. Table 13. LED Diagnostic Register Address Register HEX Address 0x1C 0x1D Key KEYA KEYB D7 D6 D5 DP A B Segment D4 D3 C D D2 D1 D0 E F G Note: If I²C self addressing is used segment G&F of KEYA is used for the two LSB of the I²C address. In this case these two nodes cannot be used as a key. Additionally the debounce time is disabled for these two bits. The data within the keyscan register is updated continuously during every cycle (1/10 of refresh rate). Therefore, to get a valid readback of keys it is recommended to read out the keyscan registers immediately after the IRQ is triggered. www.austriamicrosystems.com Revision 1.03 15 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n Display-Test Mode The AS1115 can detect open or shorted LEDs. Readout of either open LEDs or short LEDs is possible, as well as a OR relation of open and short. Note: All settings of the digit- and control-registers are maintained. Table 14. Testmode Register Summary D7 X D6 RSET_short D5 RSET_open D4 LED_global D3 LED_test D2 LED_open D1 LED_short D0 DISP_test Table 15. Testmode Register Bit Description (Address (HEX) = 0x0F)) Addr: 0x0F Bit Address Bit Name Default Access D7:D0 D0 DISP_test 0 W Optical display test. (Testmode for external visual test.) 0: Normal operation; 1: Run display test (All digits are tested independently from scan limit & shutdown register.) D1 LED_short 0 W Starts a test for shorted LEDs. (Can be set together with D2) 0: Normal operation; 1: Activate testmode D2 LED_open 0 W Starts a test for open LEDs. (Can be set together with D1) 0: Normal operation; 1: Activate testmode D3 LED_test 0 R Indicates an ongoing open/short LED test 0: No ongoing LED test; 1: LED test in progress D4 LED_global 0 R Indicates that the last open/short LED test has detected an error 0: No error detected; 1: Error detected D5 RSET_open 0 R Checks if external resistor RSET is open 0: RSET correct; 1: RSET is open D6 RSET_short 0 R Checks if external resistor RSET is shorted 0: RSET correct; 1: RSET is shorted 0 - Not used D7 LED Diagnostic Registers These eight registers contain the result of the LED open/short test for the individual LED of each digit. Table 16. LED Diagnostic Register Address Register HEX Address 0x14 0x15 0x16 0x17 Segment Digit D7 DIG0 DIG1 DP DIG2 DIG3 D6 D5 D4 D3 D2 D1 D0 A B C D E F G Register HEX Address 0x18 0x19 0x1A 0x1B Segment Digit D7 D6 D5 D4 D3 D2 D1 D0 DIG4 DIG5 DP DIG6 DIG7 A B C D E F G Note: If one or more short occures in the LED array, detection of individual LED fault could become ambiguous. Intensity Control Register (0x0A) The brightness of the display can be controlled by digital means using the Intensity Control Registers and by analog means using RSET (see Selecting RSET Resistor Value and Using External Drivers on page 19). The intensity can be controlled globally for all digits, or for each digit individually. The global intensity command will write intensity data to all four individual brightness registers, while the individual intesity command will only write to the associated individual intensity register. www.austriamicrosystems.com Revision 1.03 16 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n Display brightness is controlled by an integrated pulse-width modulator which is controlled by the lower-nibble of the Intensity Control Register. The modulator scales the average segment-current in 16 steps from a maximum of 15/16 down to 1/16 of the peak current set by RSET. Table 17. Intensity Register Format Duty Cycle HEX Code 1/16 (min on) 2/16 3/16 4/16 5/16 6/16 7/16 8/16 0xX0 0xX1 0xX2 0xX3 0xX4 0xX5 0xX6 0xX7 MSB 0 0 0 0 0 0 0 0 Register Data D2 D1 LSB 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 Duty Cycle HEX Code 9/16 10/16 11/16 12/16 13/16 14/16 15/16 15/16 (max on) 0xX8 0xX9 0xXA 0xXB 0xXC 0xXD 0xXE 0xXF MSB 1 1 1 1 1 1 1 1 Register Data D2 D1 LSB 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 Table 18. Intensity Register Address Register Data Register HEX Address Type Global Digit Digit Digit Digit 0x0A 0x10 0x11 0x12 0x13 D7:D4 X Digit 1 Intensity Digit 3 Intensity Digit 5 Intensity Digit 7 Intensity D3:D0 Global Intensity Digit 0 Intensity Digit 2 Intensity Digit 4 Intensity Digit 6 Intensity Scan-Limit Register (0x0B) The Scan-Limit Register controls which of the digits are to be displayed. When all 8 digits are to be displayed, the update frequency is typically 700Hz. If the number of digits displayed is reduced, the update frequency is increased. The frequency can be calculated using 10 x fOSC/(N+2), where N is the number of digits. Note: To avoid differences in brightness this register should not be used to blank parts of the display (leading zeros). Table 19. Scan-Limit Register Format (Address (HEX) = 0x0B)) Scan Limit Display digit 0 only Display digits 0:1 Display digits 0:2 Display digits 0:3 Register Data HEX Code D7:D3 D2 D1 D0 0xX0 X 0 0 0 0xX1 X 0 0 1 0xX2 X 0 1 0 0xX3 X 0 1 1 www.austriamicrosystems.com Scan Limit Display digits 0:4 Display digits 0:5 Display digits 0:6 Display digits 0:7 Revision 1.03 Register Data HEX Code D7:D3 D2 D1 D0 0xX4 X 1 0 0 0xX5 X 1 0 1 0xX6 X 1 1 0 0xX7 X 1 1 1 17 - 24 AS1115 Datasheet - D e t a i l e d D e s c r i p t i o n Feature Register (0x0E) The Feature Register is used for enabling various features including switching the device into external clock mode, applying an external reset, selecting code-B or HEX decoding, enabling or disabling blinking, setting the blinking rate, and resetting the blink timing. Note: At power-up the Feature Register is initialized to 0. Table 20. Feature Register Summary D7 blink_ start D6 D5 D4 D3 D2 D1 D0 sync blink_ freq_sel blink_en NU decode_sel reg_res clk_en Table 21. Feature Register Bit Descriptions (Address (HEX) = 0xXE) Feature Register Enables and disables various device features. Bit Name Default Access Bit Description External clock active. clk_en 0 R/W 0 = Internal oscillator is used for system clock. 1 = Pin CLK of the serial interface operates as system clock input. Resets all control registers except the Feature Register. 0 = Reset Disabled. Normal operation. reg_res 0 R/W 1 = All control registers are reset to default state (except the Feature Register) identically after power-up. Note: The Digit Registers maintain their data. Selects display decoding for the selected digits (Table 8 on page 13). decode_sel 0 = Enable Code-B decoding (see Table 9 on page 14). 0 R/W 1 = Enable HEX decoding (see Table 10 on page 14). NU Not used Enables blinking. blink_en 0 R/W 0 = Disable blinking. 1 = Enable blinking. Sets blink with low frequency (with the internal oscillator enabled): blink_freq_sel 0 = Blink period typically is 1 second (0.5s on, 0.5s off). 0 R/W 1 = Blink period is 2 seconds (1s on, 1s off). Synchronizes blinking on the rising edge of pin LD/CS. The multiplex and blink timing counter is cleared on the rising edge of pin LD/CS. By sync 0 R/W setting this bit in multiple devices, the blink timing can be synchronized across all the devices. Start Blinking with display enabled phase. When bit D4 (blink_en) is set, bit D7 determines how blinking starts. blink_start 0 R/W 0 = Blinking starts with the display turned off. 1 = Blinking starts with the display turned on. Addr: 0xXE Bit D0 D1 D2 D3 D4 D5 D6 D7 www.austriamicrosystems.com Revision 1.03 18 - 24 AS1115 Datasheet - Ty p i c a l A p p l i c a t i o n 9 Typical Application Selecting RSET Resistor Value and Using External Drivers Brightness of the display segments is controlled via RSET. The current that flows into ISET defines the current that flows through the LEDs. Segment current is about 200 times the current in ISET. Typical values for RSET for different segment currents, operating voltages, and LED voltage drop (VLED) are given in Table 22 & Table 23. The maximum current the AS1115 can drive is 47mA. If higher currents are needed, external drivers must be used, in which case it is no longer necessary that the devices drive high currents. Note: The display brightness can also be logically controlled (see Intensity Control Register (0x0A) on page 16). Table 22. RSET vs. Segment Current and LED Forward Voltage, VDD = 2.7V & 3.3V & 3.6V VLED VLED VLED 2.0V 1.5V 2.0V 2.5V 1.5V 2.0V 2.5V 3.0V 5kΩ 6.9kΩ 10.7kΩ 22.2kΩ 4.4kΩ 5.9kΩ 9.6kΩ 20.7kΩ 6.7kΩ 9.1kΩ 13.9kΩ 28.8kΩ 6.4kΩ 8.8kΩ 13.3kΩ 27.7kΩ 5.7kΩ 8.1kΩ 12.6kΩ 26kΩ 7.5kΩ 10.18kΩ 15.6kΩ 31.9kΩ 7.2kΩ 9.8kΩ 15kΩ 31kΩ 6.6kΩ 9.2kΩ 14.3kΩ 29.5kΩ 5.5kΩ 7.5kΩ 13kΩ 27.3kΩ VDD = 3.6V 1.5V VDD = 3.3V 40 30 20 10 VDD = 2.7V ISEG (mA) Table 23. RSET vs. Segment Current and LED Forward Voltage, VDD = 4.0V & 5.0V VLED VDD = 4.0V 40 30 20 10 1.5V 2.0V 2.5V 8.6kΩ 8.3kΩ 11.6kΩ 11.2kΩ 17.7kΩ 17.3kΩ 36.89kΩ 35.7kΩ VLED 3.0V 3.5V 7.9kΩ 7.6kΩ 5.2kΩ 10.8kΩ 9.9kΩ 7.8kΩ 16.6kΩ 15.6kΩ 13.6kΩ 34.5kΩ 32.5kΩ 29.1kΩ VDD = 5.0V ISEG (mA) 1.5V 2.0V 11.35kΩ 15.4kΩ 23.6kΩ 48.9kΩ 11.12kΩ 15.1kΩ 23.1kΩ 47.8kΩ 2.5V 3.0V 10.84kΩ 10.49kΩ 14.7kΩ 14.4kΩ 22.6kΩ 22kΩ 46.9kΩ 45.4kΩ 3.5V 4.0V 10.2kΩ 13.6kΩ 21.1kΩ 43.8kΩ 9.9kΩ 13.1kΩ 20.2kΩ 42kΩ Calculating Power Dissipation The upper limit for power dissipation (PD) for the AS1115 is determined from the following equation: PD = (VDD x 5mA) + (VDD - VLED)(DUTY x ISEG x N) (EQ 1) Where: VDD is the supply voltage. DUTY is the duty cycle set by intensity register (page 17). N is the number of segments driven (worst case is 8) VLED is the LED forward voltage ISEG = segment current set by RSET Dissipation Example: ISEG = 40mA, N = 8, DUTY = 15/16, VLED = 2.2V at 40mA, VDD = 5V (EQ 2) PD = 5V(5mA) + (5V - 2.2V)(15/16 x 40mA x 8) = 0.865W (EQ 3) Thus, for a TQFN(4x4)-24 package ΘJA = +30.5°C/W, the maximum allowed TAMB is given by: TJ,MAX = TAMB + PD x ΘJA = 150°C = TAMB + 0.865W x 30.5°C/W (EQ 4) In this example the maximum ambient temperature must stay below 123.61°C. www.austriamicrosystems.com Revision 1.03 19 - 24 AS1115 Datasheet - Ty p i c a l A p p l i c a t i o n 8x8 Dot Matrix Mode The application example in Figure 26 shows the AS1115 in the 8x8 LED dot matrix mode. The LED columns have common cathodes and are connected to the DIG0:7 outputs. The rows are connected to the segment drivers. Each of the 64 LEDs can be addressed separately. The columns are selected via the digits as listed in Table 6 on page 12. The Decode Enable Register (see page 13) must be set to ‘00000000’ as described in Table 8 on page 13. Single LEDs in a column can be addressed as described in Table 11 on page 15, where bit D0 corresponds to segment G and bit D7 corresponds to segment DP. Figure 26. Application Example as LED Dot Matrix Driver VDD 2.7 to 5V DIG0 to DIG7 9.53kΩ ISET SDA SCL µP IRQ SDA AS1115 SEG A to G SEP DP Diode Arrangement SCL IRQ GND Keyscan The key readback of the AS1115 can be used either for push buttons as well as switches. If only a single key is pressed (shorted) at a time no additional diodes are required. If a detection of multiple simultaneous keystrokes is required diodes within the keypath, as shown in Figure 27, are required. Pressing multiple keys without the diodes would result in ambiguous results. Since KEYA and KEYB have independent inputs only keys on the same path are affected. Figure 27. Keyscan Configuration SEGA SEGB SEGC SEGD SEG E SEGF SEGG SEGDP KEYA KEYB IRQ Diodes are optional and only required if multiple keystrokes must be detected simultaneously. If I²C Self-Adressing is used these two keys cannot be used for readback and must be either hard wired opened or shorted. A short writes a logical “1” whereas an open writes a logical “0” as address bit. Supply Bypassing and Wiring In order to achieve optimal performance the AS1115 should be placed very close to the LED display to minimize effects of electromagnetic interference and wiring inductance. Furthermore, it is recommended to connect a 10µF and a 0.1µF ceramic capacitor between pins VDD and GND to avoid power supply ripple (see Figure 26). www.austriamicrosystems.com Revision 1.03 20 - 24 AS1115 Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s 10 Package Drawings and Markings The AS1115 is available in the QSOP-24 package. Figure 28. QSOP-24 Package Symbol A A1 A2 b C D E E1 e h L θ Min Max 1.35 1.75 0.10 0.25 1.37 1.57 0.20 0.30 0.19 0.25 8.55 8.74 5.79 6.20 3.81 3.99 0.635 BSC 0.22 0.49 0.40 1.27 0º 8º www.austriamicrosystems.com Revision 1.03 21 - 24 AS1115 Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s Figure 29. TQFN(4x4)-24 Package 19 20 21 22 23 24 18 1 17 2 16 3 15 4 14 5 13 6 12 11 10 9 8 7 m m Symbol A A1 A3 b D E D2 E2 Min 0.50 0.00 0.18 2.70 2.70 Typ 0.55 0.152REF 0.23 4.00BSC 4.00BSC 2.80 2.80 Max 0.60 0.05 0.28 2.90 2.90 Symbol e L L1 aaa bbb ccc ddd eee Min 0.30 0.00 Typ 0.50BSC 0.35 Max 0.40 0.10 0.10 0.10 0.10 0.05 0.08 Notes:Unilateral coplanarity zone applies to the exposed heat sink slug as well as the terminals. 1. Dimensioning and tolerancing conform to ASME Y14.5M-1994. 2. All dimensions are in millimeters; angles in degrees. 3. Dimension b applies to metallized terminal and is measured between 0.25mm and 0.30mm from terminal tip. Dimension L1 represents terminal full back from package edge up to 0.1mm is acceptable. 4. Coplanarity applies to the exposed heat slug as well as the terminal. 5. Radius on terminal is optional. www.austriamicrosystems.com Revision 1.03 22 - 24 AS1115 Datasheet - O r d e r i n g I n f o r m a t i o n 11 Ordering Information The devices are available as the standard products shown in Table 24. Table 24. Ordering Information Part AS1115-BSST AS1115-BQFT Marking AS1115 ASSD Delivery Form Tape and Reel Tape and Reel Package QSOP-24 TQFN(4x4)-24 All devices are RoHS compliant and free of halogene substances. www.austriamicrosystems.com Revision 1.03 23 - 24 AS1115 Datasheet Copyrights Copyright © 1997-2009, austriamicrosystems AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. 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Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. Contact Information Headquarters austriamicrosystems AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten - Graz, Austria Tel: +43 (0) 3136 500 0 Fax: +43 (0) 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: http://www.austriamicrosystems.com/contact-us www.austriamicrosystems.com Revision 1.03 24 - 24