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Technical content
The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30
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1 General Description
chip diagnostic readMback function. highMvolume transmission applications. the detailed temperature/openMLED/shortedMLED diagnostics results. display flicker during fault testing. Figure 1. AS1123 - Typical Application Diagram
2 Key Features
3 Applications
4 Pinout
Figure 2. Pin Assignments (Top View) modes. Data is transferred to the data register at the rising edge of these pins. to sink current independent of the AS1123 mode. 0 = Output drivers are enabled. 1 = Output drivers are disabled. 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. ground plane to maximize power dissipation.
www.austriamicrosystems.com/LEDMDriverMICs Revision 1.00 3 M 24 AS1123 Datasheet M Absolute Maximum Ratings
5 Absolute Maximum Ratings
Stresses beyond those listed in T able 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 ab solute maximum rating conditions for extended periods may affect device reliability. T able 2. Absolute Maximum Ratings Parameter Min Max Units Comments Electrical Parameters VDD to GND 0 7 V Input Voltage M0.4 V DD +0.4 V O utput Voltage M0.4 7 V GND Pin Current 2000 mA 24Mpin QSOP package 2800 mA 24Mpin TQFN (4x4mm) package Input Current (latchMup immunity) M100 +100 mA Norm: JEDEC 78 Electrostatic Discharge Electrostatic Discharge HBM +/M 1 kV Norm: MIL 883 E method 3015 Temperature Ranges and Storage Conditions Thermal Resistance Θ JA 88 ºC/W o n PCB, 24Mpin QSOP package 23 ºC/W on PCB, 24Mpin TQFN (4x4mm) package Junction Temperature 150 °C Storage Temperature M55 150 ºC Package Body Temperature +260 ºC 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 PbMfree leaded packages is matte tin (100% Sn). Humidity 5 85 % NonMcondensing Moisture Sensitive Level 3 Represents a max. floor life time of 168h ams AG Technical content still valid
www.austriamicrosystems.com/LEDMDriverMICs Revision 1.00 4 M 24 AS1123 Datasheet M Electrical Characteristics
6 Electrical Characteristics
V DD = +3.0V to +5.5V, T ypical values are at TAMB = +25°(unless otherwise specified). All limits are guaranteed. The parameters with min and m ax values are guaranteed with production tests or SQC (Statistical Quality Control) methods. T able 3. Electrical Characteristics Symbol Parameter Condition Min Typ Max Unit TAMB O perating Ambient Temperature M40 +85 °C TJ O perating Junction Temperature M40 +125 °C VDD S upply Voltage 3.0 5.5 V VDS O utput Voltage OUTN0:15 0 5.5 V IOUT Output Current O UTN0:15, VDD = 5V 0 .5 40 mAIOH SDO M 1.0 IOL SDO 1 .0 VIH Input Voltage H igh Level CLK, OEN, LD, SDI 0.7 x VDD VDD + V VIL Low Level M 0.3 0.3 x VDD IDS(OFF) Output Leakage Current O EN = 1, VDS = 5.5V 1 .5 µA VOL Output V oltage SDO IOL = +1.0mA 0 .4 V VOH IOH = M1.0mA VDD M .4V IAV1 DeviceMtoMDevice Average Output Current f rom OUTN0 to OUTN15 VDS = 0.6V, VDD = Const., REXT = 470Ω 3 8.8 41.2 mA ΔIAV1 Current Skew Between Channels) VDS ≥ 0.6V, V DD = Const., REXT = 470Ω ± 1 ±3 % IAV2 DeviceMtoMDevice Average Output Current f rom OUTN0 to OUTN15 VDS = 0.5V, VDD > 3.3V, REXT = 1.87kΩ 9.6 10.4 mA ΔIAV2 Current Skew Between Channels) VDS ≥ 0.5V, V DD = Const., REXT = 1.87kΩ ± 1 ±4 % %/ΔVDS Output Current vs. O utput Voltage Regulation VDS within 1.0 and 3.0V @ IOUT = 40mA ± 0.7 %/V %/ΔVDD Output Current vs. S upply Voltage Regulation VDD within 3.0 and 5.0V ± 0.2 %/V RIN(UP) Pullup Resistance O EN 250 500 800 k Ω RIN(DOWN) Pulldown Resistance L D 250 500 800 k Ω VTHL Error Detection Threshold Voltage 0 .25 0.3 0.45 V VTHH Error Detection Threshold Voltage Level1 = default) VDD = 3.0V 1 .6 V VDD = 5.0V 2 .7 Error Detection Threshold Voltage (Level2) VDD = 3.0V 2 .4 V VDD = 5.0V 4 TOV1 Overtemperature Threshold Flag 1 50 ºC IDD(OFF) Supply Current REXT = 470Ω , OUTN0:15 = Off 4 5.5 mA REXT = 1.87kΩ , OUTN0:15 = Off 2 3.5 IDD(ON) REXT = 470Ω , OUTN0:15 = On 15 18 REXT = 1.87kΩ , OUTN0:15 = On 5 7 ams AG Technical content still valid
www.austriamicrosystems.com/LEDMDriverMICs Revision 1.00 5 M 24 AS1123 Datasheet M Electrical Characteristics Switching Characteristics V DD = 3.0 to 5.5V, VDS = 0.8V, VIH = VDD , VIL = GND, R EXT = 940Ω , V LOAD = 4.0V, RLOAD = 64Ω , C LOAD = 10pF; The Switching Charac- t eristics are guaranteed by design. * If multiple AS1123 devices are cascaded and tr or tf is large, it may be critical to achieve the timing required for data transfer between two casM c aded LED drivers. T able 4. Switching Characteristics for V DD = 5V Symbol Parameter Conditions Min Typ Max Unit tP1 Propagation Delay Time Without Staggered Output Delay) CLK M SDO 5 10 ns tP2 LD M OUTNn 250 500 nstP3 O EN M OUTNn 250 500 tP4 Propagation Delay Time 1 0 ns tW(CLK) P ulse Width CLK 15 nstW(L) LD 1 5 tW(OE) O EN (@IOUT < 40mA) 5 00 tR * CLK Rise Time 500 ns tF * CLK Fall Time 500 ns tOR Output Rise Time of VOUT (Turn Off) t bd 500 ns tOF Output Fall Time of VOUT (Turn On) t bd 500 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 2 000 ns tSTAG Staggered Output Delay only for AS1123B) 20 40 ns tSU(OE) Output Enable Setup Time 2 0 ns tGSW(ERROR) Global Error Switching Setup Time 1 0 ns tSU(ERROR) Global Error Detection Setup Time 1 0 ns tP(I/O) Propagation Delay Global Error Flag 5 ns tSW(ERROR) Switching Time Global Error Flag 1 0 ns fCLK Clock Frequency (Cascade Operation) 3 0 MHz tP3,ON LowMCurrent Test Mode P ropagation Delay Time Turn ON 3 5 µs tP3,OFF Turn OFF 0 .05 0.1 µs tREXT2,1 External Resistor Reaction Time C hange from REXT1 = 470Ω , I OUT1 = 40mA to REXT2 = 4.7kΩ , I OUT2 = 4mA 0 .5 1 µs tREXT2,1 External Resistor Reaction Time C hange from REXT1 = 4.7kΩ , I OUT1 = 4mA to REXT2 = 470Ω , I OUT2 = 40mA 0 .5 1 µs ams AG Technical content still valid
7 Typical Operating Characteristics
V DD = +3.0V to +5.5V, TAMB = 25º C (unless otherwise specified) . Figure 3. Output Current vs. Output Voltage Figure 4. ICOC vs. Supply Voltage; REXT = 470 Ω Figure 7. LED Error Detection Threshold vs. Supply Voltage
www.austriamicrosystems.com/LEDMDriverMICs Revision 1.00 7 M 24 AS1123 Datasheet M Detailed Description
8 Detailed Description
The AS1123 is designed to drive up to 16 LEDs through a fast serial interface and 16 constantMcurrent output drivers. Furthermore, the AS1123 p rovides diagnostics for detecting openM or shortedMLEDs, as well as overMtemperature conditions for LED display systems, especially LED traffic sign applications. The AS1123 contains an 16Mbit shift register and an 16Mbit data register, which convert serial input data into parallel output format. At AS1123 outM put stages, sixteen regulated current sinks are designed to provide uniform and constant current with excellent matching between ports for drivM ing LEDs within a wide range of forward voltage variations. External output current is adjustable from 0.5 to 40mA using an external resistor for flexibility in controlling the brightness intensity of LEDs. The AS1123 guarantees to endure 5.5V maximum at the outputs. The serial interface is capable of operating at a minimum of 30 MHz, satisfying the requirements of highMvolume data transmission. Using a multiplexed input/output technique, the AS1123 adds additional functionality to pins SDO, LD and OEN. These pins provide highly useful functions (openM and shortedMLED detection, overMtemperature detection), thus reducing pin count. OverMtemperature detection will work onMtheM run, whereas the openM and shortedMLED detection can be used onMtheMrun or in lowMcurrent diagnostic mode (see page 14). Fi gure 8. AS1123 - Block Diagram AS1123 REXT O EN CLK SDI LD Current Generators Detailed Error Detection 16-Bit Data Register 16-Bit Shift Register Temperature Detection 16-Bit Open Detection & Error Register 16-Bit Short Detection & Error Register Global Error Detection SDO Indicates 16 Bit Control Logic +V LED OUTN0 OUTN1 OUTN2 OUTN3 OUTN4 OUTN5 OUTN6 OUTN7 OUTN8 OUTN9 OUTN10 OUTN11 OUTN12 OUTN13 OUTN14 OUTN15 ams AG Technical content still valid
register will latchMin the corresponding error data of temperatureM, openM, and shortMerror register with each falling edge of LD. put drivers to switch on the corresponding LEDs as OEN goes low. This section contains timing diagrams referenced in other sections of this data sheet. Figure 10. Output Delay Timing Diagram
Figure 11. Data Input Timing Diagram
16 CLK Pulses
Figure 13. Switching Global Error Mode Timing Diagram are switched on during test time. To switch between errorMdetection modes clock pulses are needed (see Table 5). te: To test all LEDs, a test pattern that turns on all LEDs must be input to the AS1123. (TFLAG, OFLAG, SFLAG ) is delivered to pin SDO if any errors are encountered. ote: For a valid result SDI must be 1 for the first device. error occurs, the detailed error report can be run to identify which AS1123, or LED produced the error. Note: When no error has occurred, the detailed error report can be skipped, setting LD and subsequently OEN low. 0 Don't Care OverMTemperature Detection TFLAG = SDO = 1: No overMtemperature warning. TFLAG = SDO = 0: OverMtemperature warning. Enabled OpenMLED Detection OFLAG = SDO = 1: No openMLED error. OFLAG = SDO = 0: OpenMLED error. Enabled ShortedMLED Detection SFLAG = SDO = 1: No shortedMLED error. SFLAG = SDO = 0: ShortedMLED error.
4 Don't Care VTHH Level S DI = 1: Level1, VTHH set to 54% VDD (default)
www.austriamicrosystems.com/LEDMDriverMICs Revision 1.00 11 M 24 AS1123 Datasheet M Detailed Description Error Detection Functions Open-LED Detection The AS1123 openMLED detection is based on the comparison between VDS and VTHL . The open LED status is aquired at the rising edge of O EN and stored internally. While detecting openMLEDs 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. Shorted-LED The AS1123 shortedMLED detection is based on the comparison between VDS and VTHH . The shortened LED status is acquired at the rising e dge of OEN and stored internally. While detecting shortedMLEDs the output port must be turned on. ShortedMLED 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 lowMcurrent diagnostic mode operating conditions. This can be a chieved by reducing the VLED voltage or by adding additional diodes, resistors or LED’s. N ote: LEDs which are turned off at test time cannot be tested and will be shown as a logic 1 in the detailed error report. Overtemperature Thermal protection for the AS1123 is provided by continuously monitoring the device’s core temperature. The overtemperature status is acquired a t the rising edge of OEN and stored internally. T able 6. Open LED Detection Modes Output Port State Effective Output Point Conditions Detected Open-LED Error Status Code Meaning On V DS < VTHL 0 O pen Circuit On VDS > VTHL 1 N ormal T able 7. Shorted LED Detection Modes Output Port State Effective Output Point Conditions Detected Shorted-LED Error Status Code Meaning On V DS > VTHH 0 Short Circuit On VDS < VTHH 1 N ormal T able 8. Overtemperature Modes Output Port State Effective Output Point Conditions Detected Overtemperature Status Code Meaning Don’t Care Temperature > TOV1 0 O vertemperature Condition Don’t Care Temperature < TOV1 1 N ormal ams AG Technical content still valid
drivers, at the falling edge of OEN. 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. it0 of the 16bit data word represents the temperature flag of the chip. Figure 14. Detailed T emperature Warning Report Timing Diagram The 0 in the detailed temperature warning report indicates that IC3 is the device with the overMtemperature condition. Note: In an actual report there are no spaces in the output. For detailed timing information see T iming Diagrams on page 8.
www.austriamicrosystems.com/LEDMDriverMICs Revision 1.00 13 M 24 AS1123 Datasheet M Detailed Description Detailed Open-LED Error Report The detailed openMLED error report can be read out immediately after global error mode has been run. SDI must be 1 for the first device. F igure 15. Detailed Open-LED Error Report Timing Diagram Detailed OpenMLED Error Report Example: Consider a case where three AS1123s 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 openMLED 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: 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 lowMcurrent diagnostic mode first (see LowMCurrent Diagnostic Mode on page 14) to reduce screen fl ickering. This test can be used also onMtheMfly without using an all 1s test pattern (see Figure 19 on page 16). No te: 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. Input Data: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 LED Status: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 X X 1 1 1 1 1 1 1 1 X 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Failure Code: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Acquisition of Error Status Global Flag Readout Detailed Error Report Readout SDI OEN LD CLK SDO tH(L) Open Error Report Output New Data Input tP4 tP1tP4 tSW(ERROR) tSU(ERROR) tTESTING DBit0DBit1DBit2DBitnDBit12DBit13DBit14 OBit0OBit1OBit2OBitnOBit12OBit13OBit14 Don’t Care Don’t Care OBit15TFlag O Flag DBit15 For detailed timing information see T iming Diagrams on page 8. tGSW(ERROR) tGSW(ERROR) tGSW(ERROR) ams AG Technical content still valid
The detailed shortedMLED error report can be read out immediately after global error mode has been run ( see Global Error Mode on page 10). I must be 1 for the first device. Figure 16. Detailed Shorted-LED Error Report Timing Diagram shorted LED. This test is used onMtheMfly. reduce onMscreen flickering. reduce this onMscreen flickering. AS1123 has this currentMreduction capability builtMin, thereby minimizing the number of external components required. all 1s can be written to the shift register which will be used for the next errorMdetection test. ls and the detailed error report can be read out entering errorMdetection mode. For detailed timing information see T iming Diagrams on page 8.
9 Application Information
nto lowMcurrent diagnosis mode. a logic "1" at the detailed error report. Figure 19. Normal Operation with Error Detection During Operation – 64 Cascaded AS1123s tarted at the end of each input cycle (see Figure 20).
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 Figure21 for use of an external test pattern. B of the shift register will be written into the shift register SDI of the next AS1123 in the chain. Note: When n *AS1123 devices are in one chain, n *16 clock pulses are needed to latchMin the input data. Figure 22. Cascading AS1123 Devices
www.austriamicrosystems.com/LEDMDriverMICs Revision 1.00 18 M 24 AS1123 Datasheet M Application Information Constant Current In LED display applications, the AS1123 provides virtually no current variations from channelMtoMchannel and from AS1123MtoMAS1123. This is m ostly due to 2 factors: /square6 While IOUT ³ 10mA, the maximum current skew is less than ±3% between channels and less than ±3% between AS1123 devices. /square6 In the saturation region, the characteristic curve of the output stage is flat. Thus, the output current can be kept constant regardless of the v ariations of LED forward voltages (VF). Adjusting Output Current The AS1123 scales up the reference current (IREF ) set by external resistor (REXT ) to sink a current (IOUT ) at each output port. As shown the o utput 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 c alculated by: VREXT = 1.253V ( EQ 1) IREF = VREXT /REXT (if the other end of REXT is connected to ground) ( EQ 2) IOUT TARGET = IREF *15 = (1.253V/REXT )*15 ( EQ 3) Where: REXT is the resistance of the external resistor connected to pin REXT. VREXT is the voltage on pin REXT. T he magnitude of current (as a function of REXT ) is around 40mA at 470Ω and 20mA at 940Ω . Package Power Dissipation The maximum allowable package power dissipation (PD) is determined as: PD(MAX) = (TJ -TAMB )/RTH(J-A) (EQ 4) W hen 16 output channels are turned on simultaneously, the actual package power dissipation is: P D(ACT) = (IDD*VDD ) + (IOUT *Duty*V DS *16) ( EQ 5) Therefore, to keep PD(ACT) ≤ P D(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 = M40°C to +125°C Delayed Outputs (only for AS1123B) The AS1123B has graduated delay circuits between outputs. These delay circuits can be found between OUTNn and the constant current block. The fixed delay time is 20 ns (typ) where OUTN0:3 has no delay, OUTN4:7 has 20ns delay, OUTN8:11 has 40ns delay and OUTN12:15 has 60ns delay. This delay prevents large inrush currents, which reduce power supply bypass capacitor requirements when the outputs turn on. Switching-Noise Reduction LED drivers are frequently used in switchMmode applications which normally exhibit switching noise due to parasitic inductance on the PCB. Load Supply Voltage Considering the package power dissipation limits, the AS1123 should be operated within the range of VDS = 0.4 to 1.0V. F or example, if VLED is higher than 5V, VDS may be so high that PD(ACT) > PD(MAX) where VDS = VLED M VF. In this case, the lowest possible s upply voltage or a voltage reducer (VDROP ) should be used. The voltage reducer allows VDS = (VLED MVF) M VDROP . N ote: Resistors or zener diodes can be used as a voltage reducer as shown in Figure23 on page19 . ams AG Technical content still valid
Figure 23. Voltage Reducer using Resistor (Left) and Zener Diode (Right)
Figure 24. 24-pin QSOP Marking
Figure 26. 24-pin TQFN (4x4mm) Package
Figure 27. 24-pin QSOP Package
www.austriamicrosystems.com/LEDMDriverMICs Revision 1.00 2 3 M 24 AS1123 Datasheet M Ordering Information The device is available as the standard products shown in Table 10. ) on request Note: All products are RoHS compliant and austriamicrosystems green. Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect Technical Support is found at http://www.austriamicrosystems.com/TechnicalMSupport For further information and requests, please contact us mailto:sales@austriamicrosystems.com or find your local distributor at http://www.austriamicrosystems.com/distributor T able 10. Ordering Information Ordering Code Marking Description Delivery Form Package AS1123MBQFT AS1123 ConstantMCurrent, 16MChannel LED Driver with Diagnostics Tape and Reel 24Mpin TQFN (4x4mm) AS1123MBTST AS1123 ConstantMCurrent, 16MChannel LED Driver with Diagnostics Tape and Reel 24Mpin QSOP AS1123B* AS1123B ConstantMCurrent, 16MChannel LED Driver with Diagnostics with controlled inrush Current Tape and Reel tbd ams AG Technical content still valid
www.austriamicrosystems.com/LEDMDriverMICs Revision 1.00 2 4 M 24 AS1123 Datasheet Copyrights Copyright © 1997M2011, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, AustriaMEurope. 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. All products and companies mentioned are trademarks or registered trademarks of their respective companies. Disclaimer Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. ausM triamicrosystems 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. austriamicrosystems 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 austriamicrosystems 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 lifeMsupport or lifeMsustaining equipment are specifM ically 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, austriamicrosystemsAG 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 austriamicrosystemsAG rendering of technical or other services. Contact Information Headquarters austriamicrosystems AG Tobelbaderstrasse 30 AM8141 Unterpremstaetten, 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 ams AG Technical content still valid