high performance needs great design. Datasheet: AS1110 Constant-Current, 16-Channel LED Driver with Diagnostics Please be patient while we update our brand image as austriamicrosystems and TAOS are now ams. www.ams.com A S1110 Co nstant-C urrent, 16-C hannel LED Driver with Diagnostics 1 General Description 2 Key Features 16 Constant-current output channels The AS1110 is designed to drive up to 16 LEDs through a fast serial interface and features 16 output constant current drivers and an onchip diagnostic read-back function. Excellent output current accuracy - Between channels: <3% - Between devices: <3% 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: 0.5mA 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. Diagnostic 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: 10A Fast serial interface: 50MHz The AS1110 also features a low-current diagnostic mode to minimize display flicker during fault testing. Cascaded configuration The AS1110 is available in a 24-pin SSOP and the 28-pin QFN (5x5mm) package. Extremely fast output drivers suitable for PWM 24-pin SSOP and 28-pin QFN (5x5mm) 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 AS1110 SDI CLK www.ams.com/LED-Driver-ICs/AS1110 LD OEN OUTN15 OUTN14 OUTN13 OUTN12 OUTN11 OUTN10 OUTN9 OUTN8 OUTN7 OUTN6 OUTN5 OUTN4 OUTN3 OUTN2 OUTN1 OUTN0 +VLED SDO REXT Revision 1.6 GND VDD 1 - 24 AS1110 Datasheet 4 Pin Assignments OUTN8 OUTN9 OUTN10 OUTN11 OUTN12 22 OUTN13 23 OUTN14 VDD REXT 24 OUTN15 GND 25 OEN GND 26 SDO GND 27 REXT GND 28 CLK 1 21 SDO VDD SDI Figure 2. Pin Assignments (Top View) 24 23 22 21 20 19 18 17 16 15 14 13 OUTN3 6 16 OUTN12 OUTN4 7 AS1110 24-pin SSOP 14 1 GND 13 OUTN10 OUTN7 12 OUTN9 OUTN6 11 N/C 10 OUTN8 9 OUTN5 15 OUTN11 8 2 3 4 5 6 7 8 9 10 11 12 OUTN7 17 OUTN13 OUTN6 5 OUTN5 OUTN2 OUTN4 18 OUTN14 OUTN3 28-pin QFN 5x5 OUTN2 4 OUTN1 OUTN1 OUTN0 AS1110 19 OUTN15 LD 20 OEN 3 CLK 2 SDI LD OUTN0 4.1 Pin Descriptions Table 1. Pin Descriptions Pin Number Pin Name Description SSOP QFN 1 24:27 GND Ground 2 28 SDI Serial Data Input 3 1 CLK Serial Data Clock. The rising edge of the CLK signal is used to clock data into and out of the AS1110 shift register. In error mode, the rising edge of the CLK signal is used to switch error modes. 4 2 LD Serial Data Load 5:20 3:10 12:19 OUTN0:15 Output Current Drivers. These pins are used as LED drivers or for input sense for diagnostic modes. Data is transferred to the data register at the rising edge of these pins. OEN Output Enable. The active-low pin OEN signal can always enable output drivers to sink current independent of the AS1110 mode. 0 = Output drivers are enabled. 1 = Output drivers are disabled. 21 20 22 21 SDO Serial Data Output. In normal mode SDO is latched out 8.5 clock cycles after SDI is latched 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. 23 22 REXT External Resistor Connection. This pin connects through the external resistor (REXT) to GND, to setup the load current. 24 23 VDD Positive Supply Voltage - 11 N/C Not connected www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 2 - 24 AS1110 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 VDD to GND 0 7 V Input Voltage -0.4 VDD +0.4 V Output Voltage -0.4 15 V 2000 mA 24-pin SSOP package 2800 mA 28-pin QFN (5x5mm) package 88 C/W on PCB, 24-pin SSOP package 23 C/W on PCB, 28-pin QFN (5x5mm) package GND Pin Current Thermal Resistance JA Comments Ambient Temperature -40 +85 C Storage Temperature -55 150 C Humidity 5 86 % Non-condensing kV Norm: MIL 833 E method 3015 mA EIA/JESD78 C The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD-020D "Moisture/Reflow Sensitivity Classification for NonHermetic Solid State Surface Mount Devices". The lead finish for Pb-free leaded packages is matte tin (100% Sn). Electrostatic Discharge Digital Outputs 2 All Other Pins 2 -100 (INOM x 0.5) Latch-Up Immunity Package Body Temperature Moisture Sensitivity Level +100 + INOM +260 SOIC 3 Represents a maximum floor life of 168h QFN 1 Represents an infinite floor lifetime www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 3 - 24 AS1110 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, TAMB = -40C to +85C (unless otherwise specified). Table 3. Electrical Characteristics Symbol Parameter Condition VDD Supply Voltage VDS Output Voltage IOUT IOH IDS(OFF) VOL VOH V V 100 SDO -1.0 CLK, OEN, LD, SDI SDO 5.5 15.0 Low Level Output Voltage 3.0 0 High Level Output Leakage Current Unit 0.5 SDO Input Voltage Max OUTN0:15 Output Current VIL Typ OUTN0:15, VDD = 5V (see Figure 7) IOL VIH Min 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 V A V IAV(LC1) Device-to-Device Average Output Current from OUTN0 to OUTN15 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 OUTN15 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 OUTN15 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 = 0.8V, VDD = 5.0V, REXT = 372, OUTN0:15 = On %/VDS 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) Pulldown Resistance LD 250 500 800 k VTHL Error Detection Threshold Voltage 0.25 0.3 0.45 V VTHH Error Detection Threshold Voltage VDD = 3.0V 1.2 1.3 1.4 VDD = 5.0V 2.0 2.2 2.4 TOV1 Overtemperature Threshold Flag www.ams.com/LED-Driver-ICs/AS1110 26 mA 3 % 51.55 mA 2 % 104 mA 1 2 % 0.6 0.8 mA 10 20 A 1 49.50 1 98 0.4 150 Revision 1.6 V C 4 - 24 AS1110 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 OUTN0:15 = Off 2.7 6 REXT = 744 OUTN0:15 = Off 4.3 8 REXT = 372 OUTN0:15 = Off 5.4 9 REXT = 186, OUTN0:15 = Off 9.3 13 REXT = 744 OUTN0:15 = On 6.2 11 REXT = 372 OUTN0:15 = On 10.5 15 REXT = 186 OUTN0:15 = On 19.5 26 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 for VDD = 5V Symbol Parameter Conditions Typ Max CLK - SDO 5 10 LD - OUTNn 100 200 OEN - OUTNn 100 200 tP1 tP2 Propagation Delay Time (Without Staggered Output Delay) tP3 tP4 Propagation Delay Time 10 tW(CLK) tW(L) tF CLK 15 LD 15 OEN (@IOUT < 60mA) 200 Pulse Width tW(OE) tR Min Unit ns ns ns * CLK Rise Time 500 ns * CLK Fall Time 500 ns tOR Output Rise Time of VOUT (Turn Off) 100 200 ns tOF Output Fall Time of VOUT (Turn On) 100 300 ns tSU(D) Setup Time for SDI 5 ns tH(D) Hold Time for SDI 5 ns tSU(L) Setup Time for LD 5 ns tH(L) Hold Time for LD 5 ns tTESTING OEN Time for Error Detection 2000 ns tSTAG Staggered Output Delay tSU(OE) Output Enable Setup Time 20 ns tGSW(ERROR) Global Error Switching Setup Time 10 ns tSU(ERROR) Global Error Detection Setup Time 10 ns tP(I/O) Propagation Delay Global Error Flag 5 ns tSW(ERROR) Switching Time Global Error Flag 10 ns fCLK Maximum Clock Frequency (Cascade Operation) tP3,ON tP3,OFF 20 30 Low-Current Test Mode Propagation Delay Time www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 40 50 ns MHz Turn ON 3 5 s Turn OFF 0.05 0.1 s 5 - 24 AS1110 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 4. Switching Characteristics for VDD = 5V Symbol Parameter Conditions Typ Max Unit tREXT2,1 External Resistor Reaction Time Change from REXT1 = 372, IOUT1 = 50.52mA to REXT2 = 37.2k, IOUT2 < 1mA Min 0.5 1 s tREXT2,1 External Resistor Reaction Time Change from REXT1 = 37.2k, IOUT1 = 0.5mA to REXT2 = 372, IOUT2 > 25mA 0.5 1 s * If multiple AS1110 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. www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 6 - 24 AS1110 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; VDS = 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 -2 3 10000 3.5 4 REXT () Figure 5. Output Current vs. VDS; VDD = 5V, TAMB = 25C 5 5.5 Figure 6. Output Current vs. VDS; VDD = 5V, TAMB = 25C 120 120 100 100 REXT = 186 80 IOUT (mA) . IOUT (mA) . 4.5 VDD (V) REXT = 251 60 REXT = 372 40 20 REXT = 186 80 REXT = 251 60 REXT = 372 40 20 REXT = 744 0 REXT = 744 0 0 3 6 9 12 15 0 VDS (V) 0.2 0.4 0.6 0.8 1 1.2 1.4 VDS (V) Figure 7. Output Current vs. VDD 120 IOUT (mA) . 100 VDS = 0.8V 80 VDS = 0.7V 60 VDS = 0.6V 40 VDS = 0.5V 20 0 3 3.5 4 4.5 5 5.5 VDD (V) www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 7 - 24 AS1110 Datasheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description The AS1110 is designed to drive up to 16 LEDs through a fast serial interface and 16 constant-current output drivers. Furthermore, the AS1110 provides diagnostics for detecting open- or shorted-LEDs, as well as over-temperature conditions for LED display systems, especially LED traffic sign applications. The AS1110 contains an 16-bit shift register and an 16-bit data register, which convert serial input data into parallel output format. At AS1110 output stages, sixteen 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 AS1110 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 AS1110 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 15). Figure 8. AS1110 - Block Diagram Temperature Detection REXT 16-Bit Open Detection & Error Register 16-Bit Short Detection & Error Register OUTN15 OUTN14 OUTN13 OUTN12 OUTN11 OUTN10 OUTN9 OUTN8 OUTN7 OUTN6 OUTN5 OUTN4 OUTN3 OUTN2 OUTN1 OUTN0 +VLED AS1110 Current Generators OEN LD 16-Bit Data Register CLK Detailed Error Detection Global Error Detection 16-Bit Shift Register SDI Control Logic SDO Indicates 16 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/AS1110 Revision 1.6 8 - 24 AS1110 Datasheet - D e t a i l e d D e s c r i p t i o n The 16-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 9. Normal Mode Timing Diagram tW(CLK) 50% CLK tSU(D) SDI 50% 50% tH(D) 50% 50% SDO 50% tP1 tW(L) LD 50% 50% tSU(L) OEN tH(L) OEN Low = Output Enabled OUTNx OUTNx High = Output Off 50% OUTNx Low = Output On tP2 Figure 10. Output Delay Timing Diagram tW(OE) OEN 50% 50% tP3 OUTN0 tP3 90% 90% 50% tOR tOF tSTAG tSTAG 50% OUTN1 50% 14XtSTAG 50% OUTN15 www.ams.com/LED-Driver-ICs/AS1110 50% 10% 10% Revision 1.6 14XtSTAG 50% 9 - 24 AS1110 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 11. Data Input Timing Diagram OEN tW(OE) tSU(L) LD tSU(OE) 16 CLK Pulses tW(L) CLK tSU(D) Data Bit 15 SDI0 Data Bit 14 Data Bit 13 Data Bit 12 Data Bit n Data Bit 2 Data Bit 1 Data Bit 0 Don't Care tH(D) Old Data Bit 15 SDO0 Old Data Bit 14 Old Data Bit 13 Old Data Bit 12 Old Data Bit n Old Data Bit 2 Old Data Bit 1 Old Data Bit 0 Don't Care tP1 Figure 12. Data Input Example Timing Diagram Time = 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 CLK SDI D1 LD OEN Off On Off On Off On Off On Off On Off On Off On Off On OUTN0 OUTN1 OUTN2 OUTN3 OUTN4 OUTN5 OUTN6 OUTN7 Off On Off On Off On Off On Off On Off On Off On Off On OUTN8 OUTN9 OUTN10 OUTN11 OUTN12 OUTN13 OUTN14 OUTN15 www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 10 - 24 AS1110 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 13. 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 tP4 Acquisition of Error Status OFLAG(IN) Don't Care TFLAG OFLAG tSW(ERROR) SFLAG(IN) Don't Care 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 AS1110. 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 AS1110s 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 AS1110, 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/AS1110 Revision 1.6 11 - 24 AS1110 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 AS1110 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 and will be shown as a logic 1 in the detailed error report. 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 AS1110 shorted-LED detection is based on the comparison between VDS and VTHH. The shortened LED status is aquired 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:OUTN15 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 and will be shown as a logic 1 in the detailed error report. 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 AS1110 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/AS1110 Effective Output Point Conditions Temperature > TOV1 Temperature < TOV1 Detected Overtemperature Status Code 0 1 Revision 1.6 Meaning Overtemperature Condition Normal 12 - 24 AS1110 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. At 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*16 clock cycles (n is the number of AS1110s in a chain) via pin SDO. At the same time new data can be written into the shift register, which is loaded on the next rising edge of pin LD. This pattern is shown 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. SDI must be 1 for the first device. Bit0 of the 16bit data word represents the temperature flag of the chip. Figure 14. 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 DBit15 DBit14 DBit13 DBit12 DBitn DBit2 DBit1 DBit0 Don't Care New Data Input TFLAG SDO Undefined Temperature Error Report Output tP4 TBit0 Don't Care tP1 For detailed timing information see Timing Diagrams on page 9. Detailed Temperature Warning Report Example Consider a case where four AS1110s are cascaded in one chain. The detailed error report lists the temperatures for each device in the chain: IC1:[70] IC2:[85] IC3:[170] IC4:[60] In this case, IC3 is overheated and will generate a global error, and therefore 4*16 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: XXXXXXXXXXXXXXX1 XXXXXXXXXXXXXXX1 XXXXXXXXXXXXXXX0 XXXXXXXXXXXXXXX1 The 0 in the detailed temperature warning report indicates that IC3 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/AS1110 Revision 1.6 13 - 24 AS1110 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. SDI must be 1 for the first device. Figure 15. 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) tSW(ERROR) DBit15 DBit14 DBit13 DBit12 DBitn DBit2 DBit1 Don't Care DBit0 New Data Input TFlag OFlag OBit15 OBit14 OBit13 OBit12 OBitn tP4 OBit2 Open Error Report Output OBit1 OBit0 Don't Care tP1 For detailed timing information see Timing Diagrams on page 9. Detailed Open-LED Error Report Example Consider a case where three AS1110s 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:[1111111111111111] IC2:[111XX11111111X11] IC3:[1111111111111111] IC2 has three open LEDs switched on due to input. 3*16 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 1 1 1 1 1 1 1 1 1111111111111111 1111111111111111 LED Status: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 XX1 1 1 1 1 1 1 1 X1 1 1111111111111111 Failure Code: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1110011111111011 1111111111111111 Comparing this report with the input data indicates that IC2 is the device with two open LEDs at position 4 and 5 and one open LED at position 14. For such a test it is recommended to enter low-current diagnostic mode first (see Low-Current Diagnostic Mode on page 15) to reduce screen flickering. This test can be used also on-the-fly without using an all 1s test pattern (see Figure 19 on page 17). Note: In an actual report there are no spaces in the output. LEDs turned off during test time cannot be tested and will show a logic 1 in the detailed error report. www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 14 - 24 AS1110 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 11). SDI must be 1 for the first device. Figure 16. 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) DBit15 DBit14 DBit13 DBit12 tSW(ERROR) TTFLAG FLAG OFLAG SFLAG DBitn DBit2 DBit1 New Data Input SBit15 SBit14 SBit13 SBit12 SBitn SBit2 SBit1 Shorted-LED Error Report Output tP4 Don't Care DBit0 SBit0 Don't Care tP1 For detailed timing information see Timing Diagrams on page 9. Detailed Shorted-LED Error Report Example Consider a case where three AS1110s 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 on-the-fly. IC1:[11111XX111111111] IC2:[1111111111111111] IC3:[X100011111111111] IC1 has two shorted LEDs which are switched on, IC3 has one shorted LED switched off due to input. 3*16 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 1 1 1 1 1 1 1 1 1111111111111111 0100011111111111 LED Status: 1 1 1 1 1 X X 1 1 1 1 1 1 1 1 1 1111111111111111 X111111111111111 Failure Code: 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1111111111111111 1111111111111111 Showing IC1 as the device with two shorted LEDs at position 6 and 7, and IC3 with one shorted LED at position 1. The shorted LED at position 1 of IC3 cannot be detected, since LEDs turned off at test time are not tested and will show a logic "1" at the detailed error report. To test all LEDs this test should be run with an all 1s test pattern. For a test with an all on test pattern, low-current diagnostic mode should be entered first to reduce on-screen flickering. Note: In an actual report there are no spaces in the output. LEDs turned off during test time cannot be tested and will show a logic 1 in the detailed error report. 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 diagnostic mode require additional cables, resistors, and other components to reduce the current. The AS1110 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/AS1110 Revision 1.6 15 - 24 AS1110 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 17. Switching into Low-Current Diagnostic Mode Timing Diagram Low-Current Diagnosis Mode OEN tTESTING Load Internal all 1s Test Pattern (optional) tSU(ERROR) LD tGSW(ERROR) tH(L) CLK tGSW(ERROR) tSW(ERROR) SDI SDO Re-entering Error Detection Mode (see Figure 15) (see Figure 16) Don't Care TFLAG OFLAG SFLAG Normal Operation Current tP1 For detailed timing information see Timing Diagrams on page 9. 8.7 Shutdown Mode The AS1110 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 AS1110 devices are in a chain. At the rising edge of the 4th clock pulse the shutdown bit will be read out and the AS1110 will shutdown or wakeup. Note: In shutdown mode the supply current drops down to <10A. Figure 18. 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/AS1110 0 = Shutdown tSU(D) Revision 1.6 16 - 24 AS1110 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 AS1110 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 19). LEDs turned off at test time are not tested and will show a logic "1" at the detailed error report. Figure 19. Normal Operation with Error Detection During Operation - 64 Cascaded AS1110s Display SDI SDO CLK OEN Data1 Data2 Data2 Data3 Data4 Data3 T/O or S Error Code Data0 Data0 T/O or S Error Code Data1 GEF Clock for Error Mode 0x/1x/2x T/O or S Error Code Data2 GEF Clock for Error Mode 0x/1x/2x 1024x 1024x 1024x Rising Edge of OEN Acquisition of Error Status Rising Edge of OEN Acquisition of Error Status Falling Edge of LD; Error Register is copied into Shift Register LD Current Falling Edge of LD; Error Register is copied into Shift Register 100mA GEF = Global Error Flag 9.1.2 Error Detection with Low-Current Diagnosis Mode This unique feature of the AS1110 uses an internal all 1s test pattern for a flicker free diagnosis of all LEDs. This error detection mode can be started at the end of each input cycle (see Figure 20). Figure 20. Low-Current Diagnosis Mode with Internal All 1s Test Pattern - 64 Cascaded AS1110s Low-Current Diagnosis Mode Display Data0 Data1 Data2 SDI Data1 Data2 Data3 SDO T/O or S Error Code Data0 GEF O or S Error Code from GEF All 1s Test Pattern GEF Temperature Error Code 3x Clocks Low- Clock for Error Mode Current Mode 1x/2x CLK OEN 1024x 1024x Rising Edge of OEN Acquisition of Error Status Use Internal All 1s Test Falling Edge of LD; Error Register is copied into Shift Register Pattern LD Current 1024x 100mA 100mA 0.8mA www.ams.com/LED-Driver-ICs/AS1110 GEF = Global Error Flag Revision 1.6 17 - 24 AS1110 Datasheet - A p p l i c a t i o n I n f o r m a t i o n The last pattern written into the shift register will be saved before starting low-current diagnosis mode and can be displayed immediately after the test has been performed. Low-current diagnostic mode is started with 3 clock pulses during error detection mode. Then OEN should be enabled for 2s for testing. With the rising edge of OEN the LED test is stopped, and while LD is high the desired error mode can be selected with the corresponding clock pulses. After LD and OEN go low again the previously saved pattern can be displayed at the outputs. With the next data input the detailed error code will be clocked out at pin SDO. Note: See Figure 21 for use of an external test pattern. Figure 21. Low-Current Diagnosis Mode with External Test Pattern - 64 Cascaded AS1110s Low-Current Diagnosis Mode Display SDI Data1 Data2 Data2 External all 1s Test Pattern T/O or S Error Code Data0 SDO CLK O or S Error Code from Test Pattern GEF 3x Clocks Low-Current Mode Data3 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 100mA 100mA 0.8mA GEF = Global Error Flag 9.2 Cascading Devices To cascade multiple AS1110 devices, pin SDO must be connected to pin SDI of the next AS1110 (see Figure 22). At each rising edge of CLK the LSB of the shift register will be written into the shift register SDI of the next AS1110 in the chain. Note: When n*AS1110 devices are in one chain, n*16 clock pulses are needed to latch-in the input data. Figure 22. Cascading AS1110 Devices SDI SDI AS1110 #1 CLK LD SDO OEN SDI AS1110 #2 CLK LD SDO OEN SDI AS1110 #n-1 CLK LD SDO OEN CLK LD OEN www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 18 - 24 AS1110 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9.3 Constant Current In LED display applications, the AS1110 provides virtually no current variations from channel-to-channel and from AS1110-to-AS1110. This is mostly due to 2 factors: While IOUT 10mA, the maximum current skew is less than 3% between channels and less than 6% between AS1110 devices. In the saturation region, the characteristic curve of the output stage is flat (see Figure 5 on page 7). Thus, the output current can be kept constant regardless of the variations of LED forward voltages (VF). 9.4 Adjusting Output Current The AS1110 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 7 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 50.52mA at 372 and 25.26mA at 744. Figure 3 on page 7 shows the relationship curve between the IOUT TARGET of each channel and the corresponding external resistor (REXT). 9.5 Package Power Dissipation The maximum allowable package power dissipation (PD) is determined as: PD(MAX) = (TJ-TAMB)/RTH(J-A) When 16 output channels are turned on simultaneously, the actual package power dissipation is: PD(ACT) = (IDD*VDD) + (IOUT*Duty*VDS*16) (EQ 4) (EQ 5) Therefore, to keep PD(ACT) PD(MAX), the maximum allowed output current as a function of duty cycle is: IOUT = {[(TJ-TAMB)/RTH(J-A)]-(IDD*VDD)}/VDS/Duty/16 (EQ 6) Where: TJ = 150C 9.6 Delayed Outputs The AS1110 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 ... OUTN15 has 300ns delay. This delay prevents large inrush currents, which reduce power supply bypass capacitor requirements when the outputs turn on (see Figure 11 on page 10) 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 AS1110 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 23. www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 19 - 24 AS1110 Datasheet - A p p l i c a t i o n I n f o r m a t i o n Figure 23. Voltage Reducer using Resistor (Left) and Zener Diode (Right) Voltage Supply Voltage Supply } VLED VF VDROP VDROP { VF VDS VDS AS1110 AS1110 www.ams.com/LED-Driver-ICs/AS1110 VLED Revision 1.6 20 - 24 AS1110 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 AS1110 is available in a 28-pin QFN (5x5mm) package and a 24-pin SSOP package. -A- Figure 24. 28-pin QFN (5x5mm) Package D INDEX AREA (D/2 xE/2) D2 D2/2 D/2 -B- 2 1 N N-1 6 INDEX AREA (D/2 xE/2) TOP VIEW SEE DETAIL B 4 Datum A or B NXb -A- aaa C 2x -BSEE DETAIL B aaa C 2x 5 bbb ddd C A B C BTM VIEW 0.08 C A L1 ccc C NX ODD TERMINAL SIDE Min 0.70 0.00 0.45 0.03 SEATING PLANE -C- SIDE VIEW Typ 0.75 0.02 0.20 REF 0.55 0.15 0.10 0.10 0.05 0.08 0.10 Terminal Tip 5 Max 0.80 0.05 0.65 0.15 Notes 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 Symbol D BSC E BSC D2 E2 K b e N ND NE A3 A1 e Symbol A A1 A3 L L1 aaa bbb ccc ddd eee ggg E2 E e E2/2 NXL E/2 4 Min 3.00 3.00 0.20 0.18 Typ 5.00 5.00 3.15 3.15 0.25 0.50 28 7 7 Max 3.25 3.25 0.30 Notes 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2, 5 1, 2 1, 2, 5 1, 2, 5 Notes: Unilateral coplanarity zone applies to the exposed heat sink slug as well as the terminals. 1. 2. 3. 4. Dimensioning and tolerancing conform to ASME Y14.5M-1994. All dimensions are in millimeters; angles in degrees. N is the total number of terminals. The terminal #1 identifier and terminal numbering convention shall conform to JEDEC 95 SPP-012. Details of terminal #1 identifier are optional but must be located within the zone indicated. The terminal #1 identifier may be either a mold or marked feature. 5. Dimension b applies to metallized terminal and is measured between 0.15 and 0.30mm from terminal tip. If one end of the terminal has the optional radius, the b dimension should not be measured in that radius area. 6. Dimensions ND and NE refer to the number of terminals on each D and E side, respectively. www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 21 - 24 AS1110 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 25. 24-pin SSOP Package Symbol A A1 A2 b C D E E1 e h L 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 0 8 www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 22 - 24 AS1110 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 Description Delivery Form Package AS1110-BSSU Constant-Current, 16-Channel LED Driver with Diagnostics Tubes 24-pin SSOP AS1110-BSST Constant-Current, 16-Channel LED Driver with Diagnostics Tape and Reel 24-pin SSOP AS1110-BQFR Constant-Current, 16-Channel LED Driver with Diagnostics Tray 28-pin QFN (5x5mm) AS1110-BQFT Constant-Current, 16-Channel LED Driver with Diagnostics Tape and Reel 28-pin QFN (5x5mm) Note: All products are RoHS compliant and Pb-free. 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/AS1110 Revision 1.6 23 - 24 AS1110 Datasheet 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. 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 ams AG is believed to be correct and accurate. However, ams 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 ams AG rendering of technical or other services. Contact Information Headquarters ams AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten, Austria Tel Fax : +43 (0) 3136 500 0 : +43 (0) 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: http://www.ams.com/contact www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 24 - 24 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: ams: AS1110-BQFT AS1110-BSST