high performance needs great design. Datasheet: AS1109 8-Bit LED Driver with Diagnostics Please be patient while we update our brand image as austriamicrosystems and TAOS are now ams. www.ams.com A S 110 9 Constant-Current, 8-Bit LED Driver with Diagnostics 1 General Description 2 Key Features 8 Constant-Current Output Channels The AS1109 is designed to drive up to 8 LEDs through a fast serial interface and features 8 output constant current drivers and an onchip diagnostic read-back function. Excellent Output Current Accuracy - Between Channels: 2% - Between AS1109 Devices: 2% The high clock-frequency (up to 50MHz), adjustable output current, and flexible serial interface makes the device perfectly suited for high-volume transmission applications. Output Current Per Channel: 0.5 to 100mA Output current is adjustable (up to 100mA/channel) using an external resistor (REXT). Controlled In-Rush Current Over-Temperature, Open-LED, Shorted-LED The serial interface with Schmitt trigger inputs includes an integrated shift register. Additionally, an internal data register stores the currently displayed data. Diagnostics Functions Low-Current Test Mode The device features integrated diagnostics for overtemperature, open-LED, and shorted-LED conditions. Integrated registers store global fault status information during load as well as the detailed temperature/open-LED/shorted-LED diagnostics results. Global Fault Monitoring Low Shutdown Mode Current: 3A Fast Serial Interface: up to 50MHz The AS1109 also features a low-current diagnostic mode to minimize display flicker during fault testing. Cascaded Configuration With an operating temperature range from -40 to +125C the AS1109 is also ideal for industrial applications. Fast Output Drivers Suitable for PWM 16-pin SOIC-150, The AS1109 is available in a 16-pin SOIC-150, a 16-pin QFN (4x4mm) and the 16-pin QSOP-150 package. 16-pin QFN (4x4mm) and 16-pin QSOP-150 Package 3 Applications The device is ideal for fixed- or slow-rolling displays using static or multiplexed LED matrix and dimming functions, large LED matrix displays, mixed LED display and switch monitoring, displays in elevators, public transports (underground, trains, buses, taxis, airplanes, etc.), large displays in stadiums and public areas, price indicators in retail stores, promotional panels, bar-graph displays, industrial controller displays, white good panels, emergency light indicators, and traffic signs. Figure 1. Main Diagram and Pin Assignments +VLED 16 VDD GND 1 OUTN0 OUTN1 OUTN2 OUTN3 OUTN4 OUTN5 OUTN6 OUTN7 CLK LD www.ams.com/LED-Driver-ICs/AS1109 OEN 15 REXT CLK 3 14 SDO LD 4 AS1109 SDI SDI 2 SDO REXT GND Revision 1.21 VDD OUTN0 5 AS1109 13 OEN 12 OUTN7 OUTN1 6 11 OUTN6 OUTN2 7 10 OUTN5 OUTN3 8 9 OUTN4 1 - 24 AS1109 Datasheet 4 Pin Assignments Figure 2. Pin Assignments (Top View) SDI 15 REXT CLK 3 14 SDO LD 4 13 OEN AS1109 OUTN0 5 12 OUTN7 OUTN1 6 11 OUTN6 OUTN2 7 10 OUTN5 LD 2 OUTN0 3 OUTN1 4 9 OUTN4 14 13 11 OEN AS1109 16-pin QFN (4x4mm) 10 OUTN7 9 5 16-pin QSOP-150 16-pin SOIC-150 15 12 SDO OUTN2 OUTN3 8 1 6 7 8 OUTN5 SDI 2 CLK OUTN4 16 VDD GND VDD REXT OUTN3 GND 1 16 OUTN6 4.1 Pin Descriptions Table 1. Pin Descriptions Pin Number Pin Name Description 16-pin QSOP-150 16-pin SOIC-150 16-pin QFN (4x4mm) 1 15 GND Ground 2 16 SDI Serial Data Input 3 1 CLK Serial Data Clock. The rising edge of the CLK signal is used to clock data into and at the falling edge out of the AS1109 shift register. In error mode, the rising edge of the CLK signal is used to switch error modes. 4 2 LD Serial Data Load. Data is transferred to the data register at the rising edge of this pin. 5:12 3:10 OUTN0:7 13 11 Output Current Drivers. These pins are used as LED drivers or for input sense for diagnostic modes. OEN Output Enable. The active-low pin OEN signal can always enable output drivers to sink current independent of the AS1109 mode. 0 = Output drivers are enabled. 1 = Output drivers are disabled. 14 12 SDO Serial Data Output. In normal mode SDO is clocked out 8.5 clock cycles after SDI is clocked in. In global error detection mode this pin indicates the occurrence of a global error. 0 = Global error mode returned an error. 1 = No errors. 15 13 REXT External Resistor Connection. This pin connects through the external resistor (REXT) to GND, to setup the load current. 16 14 VDD Positive Supply Voltage www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 2 - 24 AS1109 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 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 Min Max Units Comments Electrical Parameters VDD to GND -0.3 7 V Input Voltage -0.4 VDD + 0.4 V Output Voltage -0.4 15 V 1000 mA 100 mA Norm: JEDEC 78 2 kV Norm: MIL 883 E method 3015 33 C/W on PCB, 16-pin SOIC-150 package 113 C/W on PCB, 16-pin QSOP-150 package C/W on PCB, 16-pin QFN (4x4mm) package GND Pin Current Input Current (latch-up immunity) -100 Electrostatic Discharge Electrostatic Discharge HBM Temperature Ranges and Storage Conditions Thermal Resistance JA 32 Storage Temperature Range -55 +150 Package Body Temperature Humidity non-condensing Moisture Sensitive Level 5 C +260 C 85 % The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/ JEDEC J-STD-020"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). QFN and QSOP 1 Represents a maximum floor life time of unlimited Moisture Sensitive Layer (SOIC) 3 Represents a maximum floor life of 168h www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 3 - 24 AS1109 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 = +3.0V to +5.5V, Typical values measured at VDD = 5V, TAMB = 25C (unless otherwise specified). Table 3. Electrical Characteristics Symbol Parameter Condition Min TAMB Operating Temperature Range Device fully functional up to 125C VDD Supply Voltage VDS Output Voltage IOUT IOH Max Unit -40 +85 C 3.0 5.5 V OUTN0:7 0 15.0 V OUTN0:7, VDD = 5V (see Figure 8) 0.5 100 SDO -1.0 Output Current IOL SDO VIH High Level Input Voltage VIL CLK, OEN, LD, SDI Low Level IDS(OFF) VOL Output Leakage Current Output Voltage VOH SDO Typ mA 1.0 0.7 x VDD VDD + 0.3 -0.3 0.3 x VDD OEN = 1, VDS = 15.0V 0.5 IOL = +1.0mA 0.4 IOH = -1.0mA VDD 0.4V 24.5 IAV(LC1) Device-to-Device Average Output Current from OUTN0 to OUTN7 VDS = 0.5V, VDD = Const., REXT = 744 IAV(LC1) Current Skew (Between Channels) VDS 0.5V, VDD = Const., REXT = 744 IAV(LC2) Device-to-Device Average Output Current from OUTN0 to OUTN7 VDS = 0.6V, VDD > 3.3V, REXT = 372 IAV(LC2) Current Skew (Between Channels) VDS 0.6V, VDD = Const., REXT = 372 IAV(LC3) Device-to-Device Average Output Current from OUTN0 to OUTN7 VDS = 0.8V, VDD = 5.0V, REXT = 186 IAV(LC3) Current Skew (Between Channels) VDS 0.8V, VDD = Const., REXT = 186 ILC Low-Current Diagnosis Mode VDS = 0.8V, VDD = 5.0V IPD Power Down Supply Current %/VDS V A V 25.26 26 mA 0.9 3 % 50.52 51.55 mA 0.8 2 % 101 104 mA 0.5 2 % 0.6 0.8 mA VDS = 0.8V, VDD = 5.0V, REXT = 372, OUTN0:7 = On 3 20 A Output Current vs. Output Voltage Regulation VDS within 1.0 and 3.0V 0.1 %/V %/VDD Output Current vs. Supply Voltage Regulation VDD within 3.0 and 5.0V 1 %/V RIN(UP) Pullup Resistance OEN 250 500 800 k RIN(DOWN) VTHL 49.50 98 0.4 Pulldown Resistance LD 250 500 800 k * Open Error Detection Threshold Voltage No load 0.25 0.35 0.45 V * Short Error Detection Threshold Voltage VDD = 3.0V, no load 1.2 1.3 1.4 VDD = 5.0V, no load 2.0 2.2 2.4 VTHH TOV1 Overtemperature Threshold Flag www.ams.com/LED-Driver-ICs/AS1109 150 Revision 1.21 V C 4 - 24 AS1109 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 3. Electrical Characteristics (Continued) Symbol Parameter Condition IDD(OFF)0 IDD(OFF)1 Off IDD(OFF)2 IDD(OFF)3 Supply Current IDD(ON)1 IDD(ON)2 On IDD(ON)3 Min Typ Max REXT = Open OUTN0:7 = Off 1.3 2 REXT = 744 OUTN0:7 = Off 3.0 3.68 REXT = 372 OUTN0:7 = Off 4.7 5.37 REXT = 186, OUTN0:7 = Off 8.1 8.73 REXT = 744 OUTN0:7 = On 4.5 5 REXT = 372 OUTN0:7 = On 7.5 8 REXT = 186 OUTN0:7 = On 13.7 15 Unit mA 6.1 Switching Characteristics VDD = 3.0 to 5.5V, VDS = 0.8V, VIH = VDD, VIL = GND, REXT = 372, VLOAD = 4.0V, RLOAD = 64, CLOAD = 10pF; guaranteed by design. Table 4. Switching Characteristics Symbol tP1 tP2 tP3 tP4 tW(CLK) tW(L) tW(OE) tR * * tF tOR tOF tSU(D) tH(D) tSU(L) tH(L) tTESTING tSTAG tSU(OE) tGSW(ERROR) tSU(ERROR) tP(I/O) tSW(ERROR) fCLK tP3,ON tTP3,OFF tREXT2,1 tREXT2,1 Parameter Propagation Delay Time Conditions CLK - SDO LD - OUTNn OEN - OUTNn Propagation Delay Time (Without Staggered Output Delay) Min Typ 5 100 100 Propagation Delay Time CLK LD Pulse Width OEN (@IOUT < 60mA) External Resistor Reaction Time ns ns ns 500 Maximum CLK Fall Time External Resistor Reaction Time Unit 15 15 200 Maximum CLK Rise Time Output Rise Time of VOUT (Turn Off) Output Fall Time of VOUT (Turn On) Setup Time for SDI Hold Time for SDI Setup Time for LD Hold Time for LD Minimum OEN Time for Error Detection Staggered Output Delay Output Enable Setup Time Global Error Switching Setup Time Global Error Detection Setup Time Propagation Delay Global Error Flag Switching Time Global Error Flag Maximum Clock Frequency (Cascade Operation) Low-Current Test Mode Propagation Delay Time Max 10 200 200 10 ns 500 ns 100 100 200 300 20 40 ns ns ns ns ns ns ns ns ns ns ns ns ns 5 5 5 5 2000 20 10 10 5 10 30 Turn ON Turn OFF Change from REXT1 = 372, IOUT1 = 50.52mA to REXT2 = 37.2k, IOUT2 < 1mA Change from REXT1 = 37.2k, IOUT1 = 0.5mA to REXT2 = 372, IOUT2 > 25mA 50 MHz 3 0.05 0.5 5 0.1 1 s s s 0.5 1 s * If multiple AS1109 devices are cascaded and tr or tf is large, it may be critical to achieve the timing required for data transfer between two cascaded LED drivers. Note: All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality Control) methods. www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 5 - 24 AS1109 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 Figure 3. Output Current vs. REXT, VDD = 5V; VOUT = 0.8V, TAMB = 25C Figure 4. Relative Output Current Error vs. VDD, Iout/Iout@VDD = 5V - 1, TAMB = 25C 2 Relative Output Current Error (%) . 100 IOUT (mA) . 1.5 1 0.5 10 REXT = 744; VDS = 0.5V 0 -0.5 REXT = 186; VDS = 0.8V REXT = 372; VDS = 0.6V -1 -1.5 1 100 1000 REXT (Ohm) 3 3.5 5 5.5 160 REXT = 127 140 120 IOUT (mA) . REXT = 150 100 REXT = 186 80 REXT = 251 60 REXT = 372 40 140 REXT = 127 120 REXT = 150 100 REXT = 186 80 REXT = 251 60 REXT = 372 40 REXT = 744 20 REXT = 744 20 0 0 0 2 4 6 8 10 12 14 0 0.2 0.4 VDS (V) 0.6 0.8 1 1.2 1.4 VDS (V) Figure 7. Relative IOUT Error vs. Temperature VDD = 5V, Iout/Iout@25C - 1, TAMB = 25C Figure 8. Output Current vs. VDD 1 Relative Output Current Error (%) . 4.5 Figure 6. Output Current vs. VDS; VDD = 5V, TAMB = 25C 160 160 VDS = 1V 140 REXT = 372; VDS = 0.6V IOUT (mA) . 0.5 0 4 VDD (V) Figure 5. Output Current vs. VDS; VDD = 5V, TAMB = 25C IOUT (mA) . -2 10000 REXT = 186; VDS = 0.8V REXT = 744; VDS = 0.5V -0.5 120 VDS = 0.9V 100 VDS = 0.8V 80 VDS = 0.7V 60 VDS = 0.6V 40 VDS = 0.5V 20 -1 -50 0 -25 0 25 50 75 100 3 Temperature (C) www.ams.com/LED-Driver-ICs/AS1109 3.5 4 4.5 5 5.5 VDD (V) Revision 1.21 6 - 24 AS1109 Datasheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description The AS1109 is designed to drive up to 8 LEDs through a fast serial interface and 8 constant-current output drivers. Furthermore, the AS1109 provides diagnostics for detecting open- or shorted-LEDs, as well as over-temperature conditions for LED display systems, especially LED traffic sign applications. The AS1109 contains an 8-bit shift register and an 8-bit data register, which convert serial input data into parallel output format. At AS1109 output stages, eight regulated current sinks are designed to provide uniform and constant current with excellent matching between ports for driving LEDs within a wide range of forward voltage variations. External output current is adjustable from 0.5 to 100mA using an external resistor for flexibility in controlling the brightness intensity of LEDs. The AS1109 guarantees to endure 15V maximum at the outputs. The serial interface is capable of operating at a minimum of 30 MHz, satisfying the requirements of high-volume data transmission. Using a multiplexed input/output technique, the AS1109 adds additional functionality to pins SDO, LD and OEN. These pins provide highly useful functions (open- and shorted-LED detection, over-temperature detection), thus reducing pin count. Over-temperature detection will work on-therun, whereas the open- and shorted-LED detection can be used on-the-run or in low-current diagnostic mode (see page 14). Figure 9. AS1109 - Block Diagram +VLED OUTN0 OUTN1 OUTN2 OUTN3 OUTN4 Temperature Detection REXT OUTN5 8-Bit Open Detection & Error Register OUTN6 8-Bit Short Detection & Error Register OUTN7 AS1109 Current Generators OEN LD 8-Bit Data Register CLK Detailed Error Detection Global Error Detection 8-Bit Shift Register SDI Control Logic SDO Indicates 8 Bit Path 8.1 Serial Interface Data accesses are made serially via pins SDI and SDO. At each CLK rising edge, the signal present at pin SDI is shifted into the first bit of the internal shift register and the other bits are shifted ahead of the first bit. The MSB is the first bit to be clocked in. In error-detection mode the shift register will latch-in the corresponding error data of temperature-, open-, and short-error register with each falling edge of LD. www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 7 - 24 AS1109 Datasheet - D e t a i l e d D e s c r i p t i o n The 8-bit data register will latch the data of the shift register at each rising edge of LD. This data is then used to drive the current generator output drivers to switch on the corresponding LEDs as OEN goes low. 8.2 Timing Diagrams This section contains timing diagrams referenced in other sections of this data sheet. Figure 10. Normal Mode Timing Diagram tW(CLK) 50% CLK tSU(D) SDI 50% 50% 50% tH(D) 50% SDO 50% tP1 tW(L) LD 50% 50% tH(L) tSU(L) OEN OEN Low = Output Enabled OUTNx OUTNx High = Output Off 50% OUTNx Low = Output On tP2 Figure 11. Output Delay Timing Diagram tW(OE) OEN 50% 50% tP3 OUTN0 tP3 90% 90% 50% tOR tOF tSTAG tSTAG 50% OUTN1 50% 7XtSTAG 50% OUTN7 www.ams.com/LED-Driver-ICs/AS1109 50% 10% 10% Revision 1.21 7XtSTAG 50% 8 - 24 AS1109 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 12. Data Input Timing Diagram OEN tW(OE) tSU(L LD 8 CLK Pulses tSU(OE) tW(L) CLK tSU(D) Data Bit 7 SDI Data Bit 6 Data Bit 5 Data Bit 4 Data Bit 3 Data Bit 2 Data Bit 1 Data Bit 0 Don't Care tH(D) Old Data Bit 7 SDO Old Data Bit 6 Old Data Bit 5 Old Data Bit 4 Old Data Bit 3 Old Data Bit 2 Old Data Bit 1 Old Data Bit 0 Don't Care tP1 Figure 13. Data Input Example Timing Diagram Time = 0 1 2 3 4 5 6 7 D6 D5 D4 D3 D2 D1 D0 CLK SDI D7 LD OEN OUTN0 Off On OUTN1 Off On OUTN2 Off On OUTN3 Off On OUTN4 Off On OUTN5 Off On OUTN6 Off On OUTN7 Off On www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 9 - 24 AS1109 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 14. Switching Global Error Mode Timing Diagram OEN tTESTING tGSW(ERROR) LD tGSW(ERROR) tSU(ERROR) tP(I/O) tP(I/O) tP(I/O) tGSW(ERROR) CLK TFLAG(IN) SDI Don't Care SDO Acquisition of Error Status tP4 OFLAG(IN) Don't Care TFLAG OFLAG SFLAG(IN) Don't Care tSW(ERROR) SFLAG tSW(ERROR) 8.3 Error-Detection Mode Acquisition of the error status occurs at the rising edge of OEN. Error-detection mode is started on the rising edge of LD when OEN is high. The CLK signal must be low when entering error detection mode. Error detection for open- and shorted-LEDs can only be performed for LEDs that are switched on during test time. To switch between error-detection modes clock pulses are needed (see Table 5). Note: To test all LEDs, a test pattern that turns on all LEDs must be input to the AS1109. 8.4 Global Error Mode Global error mode is entered when error-detection mode is started. Clock pulses during this period are used to select between temperature, open-LED, and shorted-LED tests, as well as low-current diagnostic mode and shutdown mode (see Table 5). In global error mode, an error flag (TFLAG, OFLAG, SFLAG) is delivered to pin SDO if any errors are encountered. Table 5. Global Error Mode Selections Clock Pulses Output Port Error-Detection Mode 0 Don't Care Over-Temperature Detection 1 Enabled Open-LED Detection 2 Enabled Shorted-LED Detection 3 Don't Care Low-Current Diagnostic Mode 4 Don't Care Shutdown Mode Global Error Flag/Shutdown Condition TFLAG = SDO = 1: No over-temperature warning. TFLAG = SDO = 0: Over-temperature warning. OFLAG = SDO = 1: No open-LED error. OFLAG = SDO = 0: Open-LED error. SFLAG = SDO = 1: No shorted-LED error. SFLAG = SDO = 0: Shorted-LED error. SDI = 1: Wakeup SDI = 0: Shutdown Note: For a valid result SDI must be 1 for the first device. If there are multiple AS1109s in a chain, the error flag will be gated through all devices. To get a valid result at the end of the chain, a logic 1 must be applied to the SDI input of the first device of the chain. If one device produces an error this error will show up after n*tP(I/O) + tSW(ERROR) at pin SDO of the last device in the chain. This means it is not possible to identify which device in the chain produced the error. Therefore, if a global error occurs, the detailed error report can be run to identify which AS1109, or LED produced the error. Note: When no error has occurred, the detailed error report can be skipped, setting LD and subsequently OEN low. www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 10 - 24 AS1109 Datasheet - D e t a i l e d D e s c r i p t i o n 8.5 Error Detection Functions 8.5.1 Open-LED Detection The AS1109 open-LED detection is based on the comparison between VDS and VTHL. The open LED status is aquired at the rising edge of OEN and stored internally. While detecting open-LEDs the output port must be turned on. Open LED detection can be started with 1 clock pulse during error detection mode while the output port is turned on. Note: LEDs which are turned off at test time cannot be tested. Table 6. Open LED Detection Modes Output Port State On On 8.5.2 Effective Output Point Conditions VDS < VTHL VDS > VTHL Detected Open-LED Error Status Code 0 1 Meaning Open Circuit Normal Shorted-LED The AS1109 shorted-LED detection is based on the comparison between VDS and VTHH. The shortened LED status is acquired at the rising edge of OEN and stored internally. While detecting shorted-LEDs the output port must be turned on. Shorted-LED detection can be started with 2 clock pulses during error detection mode while the output port is turned on. For valid results, the voltage at OUTN0:OUTN7 must be lower then VTHH under low-current diagnostic mode operating conditions. This can be achieved by reducing the VLED voltage or by adding additional diodes, resistors or LED's. Note: LEDs which are turned off at test time cannot be tested. Table 7. Shorted LED Detection Modes Output Port State On On 8.5.3 Effective Output Point Conditions VDS > VTHH VDS < VTHH Detected Shorted-LED Error Status Code 0 1 Meaning Short Circuit Normal Overtemperature Thermal protection for the AS1109 is provided by continuously monitoring the device's core temperature. The overtemperature status is aquired at the rising edge of OEN and stored internally. Table 8. Overtemperature Modes Output Port State Don't Care Don't Care www.ams.com/LED-Driver-ICs/AS1109 Effective Output Point Conditions Temperature > TOV1 Temperature < TOV1 Detected Overtemperature Status Code 0 1 Revision 1.21 Meaning Overtemperature Condition Normal 11 - 24 AS1109 Datasheet - D e t a i l e d D e s c r i p t i o n 8.6 Detailed Error Reports The detailed error report can be read out after global error mode has been run. On the falling edge of LD, the detailed error report of the selected test is latched into the shift register and can be clocked out with n*8 clock cycles (n is the number of AS1109s in a chain) via pin SDO. At the same time new data can be written into the shift register, which will load on the next rising edge of pin LD. This data will show at the output drivers, at the falling edge of OEN. 8.6.1 Detailed Temperature Warning Report The detailed temperature warning report can be read out immediately after global error mode has been run. Bit0 of the 8bit data word represents the temperature flag of the chip. Figure 15. Detailed Temperature Warning Report Timing Diagram Global Flag Readout Detailed Error Report Readout OEN tH(L) tGSW(ERROR) LD t(SU)ERROR tP4 CLK SDI DBit7 DBit6 DBit5 DBit4 DBit3 DBit2 DBit1 DBit0 Don't Care New Data Input SDO TFLAG Undefined tP4 For detailed timing information see Timing Diagrams on page 8. Temperature Error Report Output TBit0 Don't Care tP1 Detailed Temperature Warning Report Example Consider a case where five AS1109s are cascaded in one chain. The detailed error report lists the temperatures for each device in the chain: IC1:[70] IC2:[85] IC3:[66] IC4:[160] IC5:[76] In this case, IC4 is overheated and will generate a global error, and therefore 5*8 clock cycles are needed to write out the detailed temperature warning report, and optionally read in new data. The detailed temperature warning report would look like this: XXXXXXX1 XXXXXXX1 XXXXXXX1 XXXXXXX0 XXXXXXX1 The 0 in the detailed temperature warning report indicates that IC4 is the device with the over-temperature condition. Note: In an actual report there are no spaces in the output. www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 12 - 24 AS1109 Datasheet - D e t a i l e d D e s c r i p t i o n 8.6.2 Detailed Open-LED Error Report The detailed open-LED error report can be read out immediately after global error mode has been run. Figure 16. Detailed Open-LED Error Report Timing Diagram Global Flag Readout Detailed Error Report Readout OEN tTESTING LD tH(L) tSU(ERROR) tGSW(ERROR) tP4 tGSW(ERROR) CLK SDI SDO Acquisition of Error Status tGSW(ERROR) DBit7 tSW(ERROR) DBit6 DBit5 DBit4 DBit3 DBit2 DBit1 Don't Care DBit0 New Data Input TFlag OFlag OBit7 tP4 OBit6 OBit5 OBit4 OBit3 OBit2 OBit1 Open Error Report Output OBit0 Don't Care tP1 For detailed timing information see Timing Diagrams on page 8. Detailed Open-LED Error Report Example Consider a case where five AS1109s are cascaded in one chain. A 1 indicates a LED is on, a 0 indicates a LED is off, and an X indicates an open LED. The open-LED test is only applied to LEDs that are turned on. This test is used with a test pattern where all LEDs are on at test time. IC1:[11111111] IC2:[111XX111] IC3:[11111111] IC4:[1X111111] IC5:[11111111] IC2 has two open LEDs and IC4 has one open LED switched on due to input. 5*8 clock cycles are needed to write the entire error code out. The detailed error report would look like this: Input Data: 1 1 1 1 1 1 1 1 11111111 11111111 11111111 11111111 LED Status: 1 1 1 1 1 1 1 1 111XX111 11111111 1X111111 11111111 Failure Code: 1 1 1 1 1 1 1 1 11100111 11111111 10111111 11111111 Comparing this report with the input data indicates that IC2 is the device with two open LEDs at position 4 and 5 and IC4 with an open LED at second position. For such a test it is recommended to enter low-current diagnostic mode first (see Low-Current Diagnostic Mode on page 14) to reduce onscreen flickering. Note: In an actual report there are no spaces in the output. LEDs turned off during test time cannot be tested. www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 13 - 24 AS1109 Datasheet - D e t a i l e d D e s c r i p t i o n 8.6.3 Detailed Shorted-LED Error Report The detailed shorted-LED error report can be read out immediately after global error mode has been run (see Global Error Mode on page 10). Figure 17. Detailed Shorted-LED Error Report Timing Diagram Global Flag Readout Detailed Error Report Readout OEN tTESTING LD tSU(ERROR) tH(L) tGSW(ERROR) tP4 tGSW(ERROR) CLK SDI SDO Acquisition of Error Status tGSW(ERROR) DBit7 DBit6 DBit5 tSW(ERROR) TTFLAG FLAG OFLAG DBit4 DBit3 DBit2 DBit1 Don't Care DBit0 New Data Input SFLAG SBit7 SBit6 SBit5 SBit4 SBit3 SBit2 SBit1 SBit0 Shorted-LED Error Report Output tP4 Don't Care tP1 For detailed timing information see Timing Diagrams on page 8. Detailed Shorted-LED Error Report Example Consider a case where five AS1109s are cascaded in one chain. A 1 indicates a LED is on, a 0 indicates a LED is off, and an X indicates a shorted LED. This test is used with a test pattern where all LEDs are on at test time. Additionally, this test should be run after starting low-current diagnostic mode (see Low-Current Diagnostic Mode on page 14). IC1:[11111XX1] IC2:[11111111] IC3:[11111111] IC4:[111X1111] IC5:[11111111] IC2 has two shorted LEDs and IC4 has one shorted LED switched on due to input. 5*8 clock cycles are needed to write the entire error code out. The detailed error report would look like this: Input Data: 1 1 1 1 1 1 1 1 11111111 11111111 11111111 11111111 LED Status: 1 1 1 1 1 X X 1 11111111 11111111 111X1111 11111111 Failure Code: 1 1 1 1 1 0 0 1 11111111 11111111 11101111 11111111 Showing IC1 as the device with two shorted LEDs at position 6 and 7, and IC4 with one shorted LED at position 4. Note: In an actual report there are no spaces in the output. LEDs turned off during test time cannot be tested. 8.6.4 Low-Current Diagnostic Mode To run the open- or shorted-LED test, a test pattern must be used that will turn on each LED to be tested. This test pattern will cause a short flicker on the screen while the test is being performed. The low-current diagnostic mode can be initiated prior to running a detailed error report to reduce this on-screen flickering. Note: Normally, displays using such a diagnosis mode require additional cables, resistors, and other components to reduce the current. The AS1109 has this current-reduction capability built-in, thereby minimizing the number of external components required. Low-current diagnostic mode can be initiated via 3 clock pulses during error-detection mode. After the falling edge of LD, a test pattern displaying all 1s can be written to the shift register which will be used for the next error-detection test. On the next falling edge of OEN, current is reduced to ILC. With the next rising edge of OEN the current will immediately increase to normal levels and the detailed error report can be read out entering error-detection mode. www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 14 - 24 AS1109 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 18. Switching into Low-Current Diagnostic Mode Timing Diagram 2s Low-Current Diagnosis Mode Global Flag Readout Load Internal all 1s Test Pattern (optional) OEN LD tSU(ERROR) tH(L) tGSW(ERROR) tP4 tTESTING tH(L) CLK tGSW(ERROR) tSW(ERROR) SDI SDO tGSW(ERROR) Re-entering Error Detection Mode Don't Care TFLAG OFLAG SFLAG tP1 For detailed timing information see Timing Diagrams on page 8. Normal Operation Current 8.7 Shutdown Mode The AS1109 features a shutdown mode which can be entered via 4 clock pulses during error-detection mode. To enable the shutdown mode a 0 must be placed at SDI after the rising edge of the 3rd clock pulse. To disable shutdown mode a 1 must be placed at SDI after the 3rd clock pulse. The shutdown/wakeup information will be latched through if multiple AS1109 devices are in a chain. At the rising edge of the 4th clock pulse the shutdown bit will be read out and the AS1109 will shutdown or wakeup. Note: In shutdown mode the supply current drops down to typically 3A. Figure 19. Shutdown Mode Timing Diagram OEN LD tSU(ERROR) CLK 1 = Wakeup SDI SDO 0 = Shutdown 1 = Wakeup TFLAG OFLAG SFLAG tP4 www.ams.com/LED-Driver-ICs/AS1109 0 = Shutdown tSU(D) Revision 1.21 15 - 24 AS1109 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9 Application Information 9.1 Error Detection The AS1109 features two types of error detection. The error detection can be used on-the-fly, for active LEDs, without any delay, or by entering into low-current diagnosis mode. 9.1.1 Error Detection On-The-Fly Error detection on-the-fly will output the status of active LEDs during operation. Without choosing an error mode this will output the temperature flag at every input/output cycle. Triggering one clock pulse for open or two clock pulses for short detection during error detection mode outputs the detailed open- or short-error report with the next input/output cycle (see Figure 20). LEDs that are turned off cannot be tested and their digits at the error output must be ignored. Figure 20. Normal Operation with Error Detection During Operation - 128 Cascaded AS1109s Display SDI SDO CLK OEN Data1 Data2 Data2 GEF T/O or S Error Code Data1 Clock for Error Mode 0x/1x/2x 1024x Rising Edge of OEN Acquisition of Error Status Current Data4 Data3 T/O or S Error Code Data0 Data0 LD Data3 GEF T/O or S Error Code Data2 Clock for Error Mode 0x/1x/2x 1024x 1024x Rising Edge of OEN Acquisition of Error Status Falling Edge of LD; Error Register is copied into Shift Register Falling Edge of LD; Error Register is copied into Shift Register 100mA GEF = Global Error Flag www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 16 - 24 AS1109 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9.1.2 Error Detection with Low-Current Diagnosis Mode This unique feature of the AS1109 uses an internal all 1s test pattern for a flicker free diagnosis of all LEDs. This error detection mode can be started anytime, and does not require any SDI input (see Figure 21). Figure 21. Low-Current Diagnosis Mode with Internal All 1s Test Pattern - 128 Cascaded AS1109s 2s Low-Current Diagnosis Mode Display Data0 Data1 SDI Data1 SDO O or S Error Code of All 1s Test Patern GEF 3x Clocks LowCurrent Mode Data2 GEF Temperature Error Code Clock for Error Mode 1x/2x 1024x CLK 1024x Rising Edge of OEN Acquisition of Error Status OEN Falling Edge of LD; Error Register is copied into Shift Register LD Load Internal All 1s Test Pattern Current 100mA 100mA 0.8mA GEF = Global Error Flag Low-current diagnosis mode is started with 3 clock pulses during error detection mode. After the three pulses of CLK, a pulse of LD loads the internal all 1s test pattern. Then OEN should be enabled for 2s for testing. With the rising edge of OEN the test of the LEDs is stopped and while LD is high the desired error mode can be selected with the corresponding clock pulses. With the next data input the detailed error code will be clocked out at SDO. Note: See Figure 22 for the use of an external test pattern. Figure 22. Low-Current Diagnosis Mode with External Test Pattern - 128 Cascaded AS1109s Display SDI SDO CLK 2s Low-Current Diagnosis Mode Data1 Data2 Data2 External all 1s Test Pattern T/O or S Error Code Data0 GEF Temperature Error Code Clock for Error Mode 1x/2x 1024x 1024x 1024x Rising Edge of OEN Acquisition of Error Status OEN Falling Edge of LD; Error Register is copied into Shift Register LD Current O or S Error Code from Test Pattern GEF 3x Clocks Low-Current Mode Data3 100mA 100mA 0.8mA GEF = Global Error Flag www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 17 - 24 AS1109 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9.2 Cascading Devices To cascade multiple AS1109 devices, pin SDO must be connected to pin SDI of the next AS1109 (see Figure 23). At each rising edge of CLK the LSB of the shift register will be written into the shift register SDI of the next AS1109 in the chain. Data at the SDI pin is clocked in at the rising edge of the CLK pulse and is clocked out at the SDO pin 8.5 clock cycles later at the falling edge of the CLK pulse. Note: When n*AS1109 devices are in one chain, n*8 clock pulses are needed to latch-in the input data. Figure 23. Cascading AS1109 Devices SDI SDI AS1109 #1 CLK LD SDO OEN SDI AS1109 #2 CLK SDO LD SDI OEN AS1109 #n-1 CLK LD SDO OEN CLK LD OEN 9.3 Constant Current In LED display applications, the AS1109 provides virtually no current variations from channel-to-channel and from AS1109-to-AS1109. This is mostly due to 2 factors: While IOUT 50mA, the maximum current skew is less than 2% between channels and less than 2% between AS1109 devices. In the saturation region, the characteristics curve of the output stage is flat (see Figure 5 on page 6). Thus, the output current can be kept constant regardless of the variations of LED forward voltages (VF). 9.4 Adjusting Output Current The AS1109 scales up the reference current (IREF) set by external resistor (REXT) to sink a current (IOUT) at each output port. As shown in Figure 3 on page 6 the output current in the saturation region is extremely flat so that it is possible to define it as target current (IOUT TARGET). IOUT TARGET can be calculated by: VREXT = 1.253V IREF = VREXT/REXT (if the other end of REXT is connected to ground) IOUT TARGET = IREF*15 = (1.253V/REXT)*15 (EQ 1) (EQ 2) (EQ 3) Where: REXT is the resistance of the external resistor connected to pin REXT. VREXT is the voltage on pin REXT. The magnitude of current (as a function of REXT) is around 100mA at 186, 50.52mA at 372 and 25.26mA at 744. Figure 3 on page 6 shows the relationship curve between the IOUT TARGET of each channel and the corresponding external resistor (REXT). www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 18 - 24 AS1109 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9.5 Package Power Dissipation The maximum allowable package power dissipation (PD) is determined as: PD(MAX) = (TJ-TAMB)/RTH(J-A) When 8 output channels are turned on simultaneously, the actual package power dissipation is: (EQ 4) PD(ACT) = (IDD*VDD) + (IOUT*Duty*VDS*8) (EQ 5) Therefore, to keep PD(ACT) PD(MAX), the allowable maximum output current as a function of duty cycle is: IOUT = {[(TJ-TAMB)/RTH(J-A)]-(IDD*VDD)}/VDS/Duty/8 (EQ 6) Where: TJ = 150C 9.6 Delayed Outputs The AS1109 has graduated delay circuits between outputs. These delay circuits can be found between OUTNn and constant current block. The fixed delay time is 20 ns (typ) where OUTN0 has no delay, OUTN1 has 20ns delay, OUTN2 has 40ns delay ... OUTN7 has 140ns delay. This delay prevents large inrush currents, which reduce power supply bypass capacitor requirements when the outputs turn on (see Figure 12 on page 9) 9.7 Switching-Noise Reduction LED drivers are frequently used in switch-mode applications which normally exhibit switching noise due to parasitic inductance on the PCB. 9.8 Load Supply Voltage Considering the package power dissipation limits (see EQ 4:6), the AS1109 should be operated within the range of VDS = 0.4 to 1.0V. For example, if VLED is higher than 5V, VDS may be so high that PD(ACT) > PD(MAX) where VDS = VLED - VF. In this case, the lowest possible supply voltage or a voltage reducer (VDROP) should be used. The voltage reducer allows VDS = (VLED -VF) - VDROP. Note: Resistors or zener diodes can be used as a voltage reducer as shown in Figure 24. Figure 24. Voltage Reducer using Resistor (Left) and Zener Diode (Right) Voltage Supply Voltage Supply } VLED VF VDROP VDROP { VF VDS AS1109 AS1109 www.ams.com/LED-Driver-ICs/AS1109 VLED VDS Revision 1.21 19 - 24 AS1109 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 product is available in a 16-pin SOIC-150, 16-pin QSOP-150, and 16-pin QFN 4x4mm package. Figure 25. 16-pin SOIC-150 Package AS1109B YYWWRZZ Symbol A A1 A2 b c D E E1 e L L1 L2 R Min 0.10 1.25 0.31 0.17 0.40 0.07 Nom 9.90 BSC 6.00 BSC 3.90 BSC 1.27 BSC 1.40 REF 0.25 BSC - Max 1.75 0.25 0.51 0.25 1.27 - Symbol R1 h 1 2 aaa bbb ccc ddd eee fff ggg N Min 0.07 0.25 0 5 0 - Nom 0.10 0.20 0.10 0.25 0.10 0.15 0.15 16 Max 0.50 8 15 - Notes: 1. Dimensioning & tolerancing conform to ASME Y14.5M-1994. 2. All dimensions are in millimeters. Angles are in degrees. Marking: YYWWRZZ. YY WW R ZZ Last two digits of the current year Manufacturing Week Plant identifier Traceability code www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 20 - 24 AS1109 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 26. 16-pin QSOP-150 Package AS1109B YYWWRZZ Symbol A A1 A2 b c D E E1 e L L1 L2 R R1 h 1 2 aaa bbb ccc ddd eee fff N Notes: 1. Dimensioning & tolerancing conform to ASME Y14.5M-1994. 2. All dimensions are in millimeters. Angles are in degrees. 3. Datums A & B to be determined at Datum H. Min 0.10 1.24 0.20 0.15 0.41 0.08 0.08 0.25 0 5 0 - Nom 4.90 BSC 6.00 BSC 3.91 BSC 0.635 BSC 1.04 REF 0.25 BSC 0.10 0.20 0.10 0.18 0.10 0.15 16 Max 1.75 0.25 0.30 0.25 1.27 0.51 8 15 - Marking: YYWWRZZ. YY WW R ZZ Last two digits of the current year Manufacturing Week Plant identifier Traceability code www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 21 - 24 AS1109 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 27. 16-pin QFN 4x4mm Package AS 1109B YYWW QZZ Symbol A A1 A3 L b D E e D2 E2 aaa bbb ccc ddd eee fff N Notes: 1. 2. 3. 4. 5. Dimensioning & tolerancing conform to ASME Y14.5M-1994. All dimensions are in millimeters. Angles are in degrees. Coplanarity applies to the exposed heat slug as well as the terminal. Radius on terminal is optional. N is the total number of terminals. Min 0.70 0 0.45 0.25 2.00 2.00 - Nom 0.75 0.02 0.20 REF 0.55 0.30 4.00 BSC 4.00 BSC 0.65 BSC 2.15 2.15 0.15 0.10 0.10 0.05 0.08 0.10 16 Max 0.80 0.05 0.65 0.35 2.25 2.25 - Marking: YYWWQZZ. YY WW Q ZZ Last two digits of the current year Manufacturing Week Plant identifier Traceability code www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 22 - 24 AS1109 Datasheet - O r d e r i n g I n f o r m a t i o n 11 Ordering Information The device is available as the standard products shown in Table 9. Table 9. Ordering Information Ordering Code Marking Description Delivery Form Package AS1109-BSOU AS1109B Constant-Current, 8-Bit LED Driver with Diagnostics Tubes 16-pin SOIC-150 AS1109-BSOT AS1109B Constant-Current, 8-Bit LED Driver with Diagnostics Tape and Reel 16-pin SOIC-150 AS1109-BSSU AS1109B Constant-Current, 8-Bit LED Driver with Diagnostics Tubes 16-pin QSOP-150 AS1109-BSST AS1109B Constant-Current, 8-Bit LED Driver with Diagnostics Tape and Reel 16-pin QSOP-150 AS1109-BQFR AS1109B Constant-Current, 8-Bit LED Driver with Diagnostics Tray 16-pin QFN (4x4mm) AS1109-BQFT AS1109B Constant-Current, 8-Bit LED Driver with Diagnostics Tape and Reel 16-pin QFN (4x4mm) Note: All products are RoHS compliant. Buy our products or get free samples online at www.ams.com/ICdirect Technical Support is available at www.ams.com/Technical-Support For further information and requests, email us at sales@ams.com (or) find your local distributor at www.ams.com/distributor www.ams.com/LED-Driver-ICs/AS1109 Revision 1.21 23 - 24 AS1109 Datasheet - O r d e r i n g I n f o r m a t i o n Copyrights Copyright (c) 1997-2012, ams AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered (R). 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. All products and companies mentioned are trademarks or registered trademarks of their respective companies. Disclaimer Devices sold by ams AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. ams AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. ams AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with ams AG for current information. This product is intended for use in normal commercial applications. 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 ams AG for each application. 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