austriamicrosystems AG is now ams AG The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30 8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: [email protected] Please visit our website at www.ams.com Da tas he et A S11 23 C o n s t a n t - C u r r e n t , 1 6 - C h a n n e l L E D D r i v e r w i th D i a g n o s t i c s 2 Key Features The AS1123 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. 16 Constant-Current Output Channels Excellent Output Current Accuracy al id 1 General Description - 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 40mA Output current is adjustable (up to 40mA/channel) using an external resistor (REXT). Over-Temperature, Open-LED, Shorted-LED Diagnostic Functions The serial interface with Schmitt trigger inputs includes an integrated shift register. Additionally, an internal data register stores the currently displayed data. Low-Current Test Mode Global Fault Monitoring am lc s on A te G nt st il lv 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. The AS1123 also features a low-current diagnostic mode to minimize display flicker during fault testing. The AS1123 is available in a 24-pin QSOP and a 24-pin TQFN (4x4mm) package. Fast Serial Interface: 50MHz Cascaded Configuration Extremely Fast Output Drivers Suitable for PWM Output Delay for controlling Inrush Current (on request) 24-pin QSOP and 24-pin TQFN (4x4mm) 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. Te LD www.austriamicrosystems.com/LED-Driver-ICs OEN REXT Revision 1.00 OUTN15 OUTN14 OUTN13 OUTN12 OUTN11 OUTN10 OUTN9 OUTN8 OUTN7 OUTN6 AS1123 SDI CLK OUTN5 OUTN4 OUTN3 OUTN2 ch ni OUTN1 OUTN0 +VLED ca Figure 1. AS1123 - Typical Application Diagram SDO GND VDD 1 - 24 AS1123 Datasheet - P i n o u t 4 Pinout Pin Assignments 18 OUTN4 OUTN12 2 AS1123 OUTN13 3 OUTN14 4 24-pin TQFN (4x4mm) OUTN15 5 QSOP TQFN 1 10 2 11 3 12 4 13 5:20 1:5, 14:24 6 lv 1 2 3 4 5 GND SDI CLK LD OUTN0 OUTN1 OUTN2 OUTN3 6 7 8 9 10 11 12 OUTN7 VDD Pin Name OUTN4 OUTN5 OUTN6 10 11 12 CLK 9 SDI 8 Description GND Ground SDI Serial Data Input CLK Serial Data Clock. The rising edge of the CLK signal is used to clock data into and out of the AS1123 shift register. In error mode, the rising edge of the CLK signal is used to switch error modes. LD Serial Data Load. Pull-down Resistor 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. Pull-up Resistor. The active-low pin OEN signal can always enable output drivers to sink current independent of the AS1123 mode. 0 = Output drivers are enabled. 1 = Output drivers are disabled. ni 21 13 LD am lc s on A te G nt st il Pin Number 24-pin QSOP ca Table 1. Pin Descriptions AS1123 14 OUTN0 GND SDO 7 Pin Descriptions 16 OUTN2 15 OUTN1 REXT OEN 6 24 23 22 21 20 19 18 17 16 15 14 13 17 OUTN3 Exposed Pad al id 1 OUTN8 24 23 22 21 20 19 OUTN11 OUTN11 OUTN10 OUTN9 VDD REXT SDO OEN OUTN15 OUTN14 OUTN13 OUTN12 OUTN5 OUTN6 OUTN7 OUTN8 OUTN9 OUTN10 Figure 2. Pin Assignments (Top View) 7 SDO 23 8 REXT External Resistor Connection. This pin connects through the external resistor (REXT) to GND, to setup the load current. 24 9 VDD Positive Supply Voltage - Exposed Pad Te ch 22 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. Exposed Pad. This pin also functions as a heat sink. Solder it to a large pad or to the circuit-board ground plane to maximize power dissipation. www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 2 - 24 AS1123 Datasheet - A b s o l u t e M a x i m u m R a t i n g s 5 Absolute Maximum Ratings Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Section 6 Electrical Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2. Absolute Maximum Ratings Min Max Units Comments al id Parameter Electrical Parameters 0 7 V -0.4 VDD+0.4 V Output Voltage -0.4 7 V 2000 mA 24-pin QSOP package 2800 mA 24-pin TQFN (4x4mm) package +100 mA Norm: JEDEC 78 GND Pin Current Electrostatic Discharge -100 am lc s on A te G nt st il Input Current (latch-up immunity) lv VDD to GND Input Voltage Electrostatic Discharge HBM +/- 1 kV Norm: MIL 883 E method 3015 Temperature Ranges and Storage Conditions Thermal Resistance ΘJA Junction Temperature Storage Temperature -55 Package Body Temperature Humidity 5 ºC/W on PCB, 24-pin QSOP package ºC/W on PCB, 24-pin TQFN (4x4mm) package 150 °C 150 ºC +260 ºC The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD-020 “Moisture/Reflow Sensitivity Classification for NonHermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). 85 % Non-condensing 3 Represents a max. floor life time of 168h Te ch ni ca Moisture Sensitive Level 88 23 www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 3 - 24 AS1123 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 are at TAMB = +25°(unless otherwise specified). All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality Control) methods. Table 3. Electrical Characteristics Parameter Condition TAMB Operating Ambient Temperature -40 TJ Operating Junction Temperature -40 VDD Supply Voltage 3.0 VDS Output Voltage IOH OUTN0:15 0 OUTN0:15, VDD = 5V 0.5 SDO -1.0 Output Current IOL SDO VIH Input Voltage VIL CLK, OEN, LD, SDI Low Level IDS(OFF) Output Leakage Current VOL Output Voltage VOH Max Unit +85 °C +125 °C 5.5 V 5.5 V 40 mA 1.0 0.7 x VDD VDD + 0.3 -0.3 0.3 x VDD am lc s on A te G nt st il High Level Typ lv IOUT Min al id Symbol OEN = 1, VDS = 5.5V 1.5 IOL = +1.0mA SDO V µA 0.4 IOH = -1.0mA VDD 0.4V 38.8 V Device-to-Device Average Output Current from OUTN0 to OUTN15 VDS = 0.6V, VDD = Const., REXT = 470Ω ∆IAV1 Current Skew (Between Channels) VDS ≥ 0.6V, VDD = Const., REXT = 470Ω IAV2 Device-to-Device Average Output Current from OUTN0 to OUTN15 VDS = 0.5V, VDD > 3.3V, REXT = 1.87kΩ ∆IAV2 Current Skew (Between Channels) VDS ≥ 0.5V, VDD = Const., REXT = 1.87kΩ ILC Low-Current Diagnosis Mode VDS = 0.8V, VDD = 5.0V %/∆VDS Output Current vs. Output Voltage Regulation VDS within 1.0 and 3.0V @ IOUT = 40mA ±0.7 %/V %/∆VDD Output Current vs. Supply Voltage Regulation VDD within 3.0 and 5.0V ±0.2 %/V RIN(UP) Pullup Resistance OEN 250 500 800 kΩ Pulldown Resistance LD 250 500 800 kΩ 0.3 0.45 V VTHL ni RIN(DOWN) ca IAV1 Error Detection Threshold Voltage ch Error Detection Threshold Voltage (Level1 = default) Te VTHH TOV1 Error Detection Threshold Voltage (Level2) Supply Current IDD(ON) www.austriamicrosystems.com/LED-Driver-ICs mA ±3 % 10.4 mA ±1 ±4 % 0.6 0.8 mA ±1 9.6 0.4 0.25 VDD = 3.0V 1.6 VDD = 5.0V 2.7 VDD = 3.0V 2.4 VDD = 5.0V 4 Overtemperature Threshold Flag IDD(OFF) 41.2 V V 150 ºC REXT = 470Ω, OUTN0:15 = Off 4 5.5 REXT = 1.87kΩ, OUTN0:15 = Off 2 3.5 REXT = 470Ω, OUTN0:15 = On 15 18 REXT = 1.87kΩ, OUTN0:15 = On 5 7 Revision 1.00 mA 4 - 24 AS1123 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 Switching Characteristics VDD = 3.0 to 5.5V, VDS = 0.8V, VIH = VDD, VIL = GND, REXT = 940Ω, VLOAD = 4.0V, RLOAD = 64Ω, CLOAD = 10pF; The Switching Characteristics are guaranteed by design. Table 4. Switching Characteristics for VDD = 5V Propagation Delay Time (Without Staggered Output Delay) tSU(OE) tGSW(ERROR) tSU(ERROR) tP(I/O) tSW(ERROR) fCLK tP3,ON tP3,OFF Typ 5 250 250 Max 10 500 500 10 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 OEN Time for Error Detection Staggered Output Delay (only for AS1123B) Output Enable Setup Time Global Error Switching Setup Time Global Error Detection Setup Time Propagation Delay Global Error Flag Switching Time Global Error Flag Clock Frequency (Cascade Operation) Low-Current Test Mode Propagation Delay Time External Resistor Reaction Time tREXT2,1 External Resistor Reaction Time ca tREXT2,1 * Unit ns ns ns ns lv CLK Fall Time tSTAG 15 15 500 OEN (@IOUT < 40mA) * tTESTING CLK LD Pulse Width CLK Rise Time tSU(D) tH(D) tSU(L) tH(L) Min Propagation Delay Time * tF tOR tOF Conditions CLK - SDO LD - OUTNn OEN - OUTNn 500 ns 500 ns tbd tbd 500 500 ns ns ns ns ns ns ns 20 40 ns 3 0.05 5 10 30 5 0.1 ns ns ns ns ns MHz µs µs 0.5 1 µs 0.5 1 µs am lc s on A te G nt st il tR Parameter al id Symbol tP1 tP2 tP3 tP4 tW(CLK) tW(L) tW(OE) 5 5 5 5 2000 20 10 10 Turn ON Turn OFF Change from REXT1 = 470Ω, IOUT1 = 40mA to REXT2 = 4.7kΩ, IOUT2 = 4mA Change from REXT1 = 4.7kΩ, IOUT1 = 4mA to REXT2 = 470Ω, IOUT2 = 40mA Te ch ni 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 cascaded LED drivers. www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 5 - 24 AS1123 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 VDD = +3.0V to +5.5V, TAMB = 25ºC (unless otherwise specified). Figure 3. Output Current vs. Output Voltage Figure 4. ICOC vs. Supply Voltage; REXT = 470Ω 42 30 20 Iout = 10mA (1.8kΩ) 10 Iout = 4mA (4.7kΩ) al id Iout = 40mA (470Ω) 40 41.5 41 40.5 40 lv Constant Output Current (mA) 50 39.5 39 38.5 am lc s on A te G nt st il Constant Output Current (mA) 60 38 0 0 0.5 1 1.5 2 2.5 3 3 3.25 3.5 Figure 5. ICOC vs. Temperature; REXT = 470Ω 4 4.25 4.5 4.75 5 Figure 6. ICOC vs. Temperature; REXT = 1.8kΩ Constant Output Current (mA) 12 41.5 41 40.5 40 39.5 39 38.5 38 11.5 11 10.5 10 9.5 9 8.5 8 -40 -15 10 35 60 85 ca Constant Output Current (mA) 42 3.75 Supply Voltage (V) Output Voltage (V) Temperature (ΣC) -40 -15 10 35 60 85 Temperature (ΣC) ni Figure 7. LED Error Detection Threshold vs. Supply Voltage Vthh - Level 1 (default) ch Error Detection Threshold (mV) 5 Vthh - Level 2 4 Vthl Te 3 2 1 0 3 3.25 3.5 3.75 4 4.25 4.5 4.75 5 Supply Voltage (V) www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 6 - 24 AS1123 Datasheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description The AS1123 is designed to drive up to 16 LEDs through a fast serial interface and 16 constant-current output drivers. Furthermore, the AS1123 provides diagnostics for detecting open- or shorted-LEDs, as well as over-temperature conditions for LED display systems, especially LED traffic sign applications. al id The AS1123 contains an 16-bit shift register and an 16-bit data register, which convert serial input data into parallel output format. At AS1123 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 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 high-volume data transmission. lv Using a multiplexed input/output technique, the AS1123 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 8. AS1123 - 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 am lc s on A te G nt st il OUTN4 OUTN3 OUTN2 OUTN1 OUTN0 +VLED AS1123 Current Generators OEN LD 16-Bit Data Register CLK Detailed Error Detection Global Error Detection ca 16-Bit Shift Register Control Logic ni SDI Te ch SDO Indicates 16 Bit www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 7 - 24 AS1123 Datasheet - D e t a i l e d D e s c r i p t i o n 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. 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. al id Timing Diagrams This section contains timing diagrams referenced in other sections of this data sheet. Figure 9. Normal Mode Timing Diagram 50% CLK SDI 50% SDO 50% tH(D) am lc s on A te G nt st il tSU(D) 50% lv tW(CLK) 50% 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 ca tP2 Figure 10. Output Delay Timing Diagram ni OEN tW(OE) 50% 50% tP3 90% 50% 10% tOF tP3 90% 50% 10% tOR Te ch OUTN0:15 www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 8 - 24 AS1123 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 tW(L) al id 16 CLK Pulses CLK Data Bit 15 Data Bit 14 Data Bit 13 Data Bit 12 Data Bit Data Bit n 2 Data Bit 1 lv tSU(D) SDI0 Data Bit 0 Don’t Care am lc s on A te G nt st il tH(D) Old Data Old Data Old Data Old Data Old Data Old Data Old Data Old Data Bit 15 Bit 14 Bit 13 Bit 12 Bit n Bit 2 Bit 1 Bit 0 SDO0 tSU(OE) Don’t Care tP1 Figure 12. Data Input Example Timing Diagram Time 0 CLK SDI OEN OUTN0 OUTN1 OUTN2 3 4 5 D12 D11 D10 6 7 8 9 10 11 12 13 14 15 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Off On Off On Off On Off On Off On Off On Off On Off On ca OUTN3 OUTN4 OUTN5 ni OUTN6 Off On Off On Off On Off On Off On Off On Off On Off On ch OUTN8 2 D15 D14 D13 LD OUTN7 1 OUTN9 OUTN10 OUTN11 Te OUTN12 OUTN13 OUTN14 OUTN15 www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 9 - 24 AS1123 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 tTESTING OEN tGSW(ERROR) tGSW(ERROR) tSU(ERROR) tP(I/O) tP(I/O) al id tP(I/O) tGSW(ERROR) CLK TFLAG(IN) SDI Don’t Care SFLAG(IN) Don’t Care am lc s on A te G nt st il Don’t Care SDO OFLAG(IN) lv LD Acquisition of Error Status tP4 TFLAG OFLAG tSW(ERROR) SFLAG tSW(ERROR) 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 AS1123. 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. Clock Pulses Output Port 0 Don't Care 1 Enabled ca Table 5. Global Error Mode Selections 2 Enabled Shorted-LED Detection Error-Detection Mode Over-Temperature Detection ch ni Open-LED Detection Don't Care Low-Current Diagnostic Mode 4 Don't Care VTHH Level 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: Level1, VTHH set to 54% VDD (default) SDI = 0: Level2, VTHH set to 80% VDD Te 3 Global Error Flag/Shutdown Condition Note: For a valid result SDI must be 1 for the first device. If there are multiple AS1123s 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 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. www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 10 - 24 AS1123 Datasheet - D e t a i l e d D e s c r i p t i o n Error Detection Functions Open-LED Detection The AS1123 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. Effective Output Point Conditions VDS < VTHL VDS > VTHL Output Port State On On al id Table 6. Open LED Detection Modes Detected Open-LED Error Status Code 0 1 Open Circuit Normal lv Shorted-LED Meaning am lc s on A te G nt st il The AS1123 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: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 Overtemperature Effective Output Point Conditions VDS > VTHH VDS < VTHH Detected Shorted-LED Error Status Code 0 1 Meaning Short Circuit Normal Thermal protection for the AS1123 is provided by continuously monitoring the device’s core temperature. The overtemperature status is acquired at the rising edge of OEN and stored internally. Table 8. Overtemperature Modes Output Port State Detected Overtemperature Status Code 0 1 Meaning Overtemperature Condition Normal Te ch ni ca Don’t Care Don’t Care Effective Output Point Conditions Temperature > TOV1 Temperature < TOV1 www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 11 - 24 AS1123 Datasheet - D e t a i l e d D e s c r i p t i o n 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 AS1123s 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. Detailed Temperature Warning Report al id 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 lv OEN tH(L) tGSW(ERROR) LD CLK am lc s on A te G nt st il t(SU)ERROR tP4 DBit15 SDI DBit14 DBit13 DBit12 DBitn DBit2 DBit1 DBit0 Don’t Care New Data Input TFLAG SDO tP4 Undefined Temperature Error Report Output TBit0 Don’t Care tP1 For detailed timing information see Timing Diagrams on page 8. Detailed Temperature Warning Report Example: Consider a case where four AS1123s 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 ca The 0 in the detailed temperature warning report indicates that IC3 is the device with the over-temperature condition. Te ch ni Note: In an actual report there are no spaces in the output. www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 12 - 24 AS1123 Datasheet - D e t a i l e d D e s c r i p t i o n 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 tTESTING LD al id OEN tH(L) tSU(ERROR) tGSW(ERROR) tP4 CLK tSW(ERROR) DBit14 DBit13 DBit12 DBitn DBit2 DBit1 Don’t Care DBit0 New Data Input TFlag SDO DBit15 am lc s on A te G nt st il SDI Acquisition of Error Status tGSW(ERROR) lv tGSW(ERROR) 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 8. Detailed Open-LED 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 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: 1111111111111111 1111111111111111 11111111 11111111 LED Status: 1111111111111111 111XX11111111X11 11111111 11111111 Failure Code: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1110011111111011 111111 1111111111 ca 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 14) 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 16). Te ch ni 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.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 13 - 24 AS1123 Datasheet - D e t a i l e d D e s c r i p t i o n 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). SDI must be 1 for the first device. Figure 16. Detailed Shorted-LED Error Report Timing Diagram Global Flag Readout Detailed Error Report Readout al id OEN LD tSU(ERROR) tH(L) tGSW(ERROR) tP4 tGSW(ERROR) CLK SDI DBit15 tSW(ERROR) TTFLAG FLAG OFLAG SDO DBit14 DBit13 DBit12 DBitn DBit2 DBit1 Don’t Care DBit0 am lc s on A te G nt st il Acquisition of Error Status tGSW(ERROR) lv tTESTING New Data Input SBit15 SFLAG SBit14 SBit13 SBit12 SBitn SBit2 SBit1 Shorted-LED Error Report Output tP4 SBit0 Don’t Care tP1 For detailed timing information see Timing Diagrams on page 8. Detailed Shorted-LED 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 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: 1111111111111111 1111111111111111 0100011111111111 LED Status: 11111XX111111111 1111111111111111 X1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Failure Code: 1111100111111111 1111111111111111 1111111111111111 ca Input Data: ni 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. ch 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. Low-Current Diagnostic Mode Te 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 AS1123 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.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 14 - 24 AS1123 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 tGSW(ERROR) tH(L) CLK tGSW(ERROR) tSW(ERROR) SDI Re-entering Error Detection Mode (see Figure 15 on page 13) (see Figure 16 on page 14) lv SDO Don’t Care TFLAG OFLAG SFLAG al id Load Internal all 1s Test Pattern (optional) tSU(ERROR) LD Normal Operation Current am lc s on A te G nt st il tP1 For detailed timing information see Timing Diagrams on page 8. VTHH Level Two different threshold levels of the error detection can be set via a bit. The bit can be entered via 4 clock pulses during error-detection mode. To set level 2 (VTHH is 80% of Vdd) a 0 must be placed at SDI after the rising edge of the 3rd clock pulse. To set level 1 (VTHH is 54% of Vdd) a 1 must be placed at SDI after the 3rd clock pulse. The level 1/level 2 information will be latched through if multiple AS1123 devices are in a chain. At the rising edge of the 4th clock pulse the bit will be read out and the AS1123 is set to Level1 or Level2. Figure 18. VTHH Level Timing Diagram OEN LD tSU(ERROR) 1 = Level1 ni ch SDI ca CLK 1 = Level1 TFLAG OFLAG SFLAG tP4 0 = Level2 tSU(D) Te SDO 0 = Levle2 www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 15 - 24 AS1123 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 Error Detection The AS1123 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. Error Detection On-The-Fly al id 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. Display Data1 Data2 SDI Data2 Data3 SDO T/O or S Error Code Data0 Data3 am lc s on A te G nt st il Data4 T/O or S Error Code Data1 GEF Clock for Error Mode 0x/1x/2x CLK OEN lv Figure 19. Normal Operation with Error Detection During Operation – 64 Cascaded AS1123s 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 Falling Edge of LD; Error Register is copied into Shift Register ≤ 40mA Current GEF = Global Error Flag Error Detection with Low-Current Diagnosis Mode This unique feature of the AS1123 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). ca Figure 20. Low-Current Diagnosis Mode with Internal All 1s Test Pattern – 64 Cascaded AS1123s Data0 Data1 T/O or S Error Code Data0 ch SDO ni Display SDI 1024x OEN Rising Edge of OEN Acquisition of Error Status Te CLK Data1 Data2 Data2 Data3 O or S Error Code from GEF All 1s Test Pattern GEF GEF Temperature Error Code 3x Clocks Low- Clock for Error Current Mode Mode 1x/2x 1024x 1024x Use Internal All 1s Falling Edge LD; Error Register is copied into Shift Register Test Pattern LD Current Low-Current Diagnosis Mode ≤ 40mA ≤ 40mA ≤ 0.8mA www.austriamicrosystems.com/LED-Driver-ICs GEF = Global Error Flag Revision 1.00 16 - 24 AS1123 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 ≥2µs 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. al id Note: See Figure 21 for use of an external test pattern. Figure 21. Low-Current Diagnosis Mode with External Test Pattern – 64 Cascaded AS1123s Low-Current Diagnosis Mode Display Data2 T/O or S Error Code Data0 SDO CLK O or S Error Code from Test Pattern GEF 3x Clocks Low-Current Mode Data3 lv Data2 External all 1s Test Pattern Temperature Error Code GEF Clock for Error Mode 1x/2x am lc s on A te G nt st il SDI Data1 1024x 1024x 1024x Rising Edge of OEN Acquisition of Error Status OEN Falling Edge LD; Error Register is copied into Shift Register LD Current ≤ 40mA ≤ 40mA ≤ 0.8mA GEF = Global Error Flag Cascading Devices To cascade multiple AS1123 devices, pin SDO must be connected to pin SDI of the next AS1123 (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 AS1123 in the chain. Note: When n*AS1123 devices are in one chain, n*16 clock pulses are needed to latch-in the input data. SDI AS1123 #1 ch SDI ni ca Figure 22. Cascading AS1123 Devices CLK LD SDO SDI OEN AS1123 #2 CLK LD SDO OEN SDI AS1123 #n-1 CLK LD SDO OEN Te CLK LD OEN www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 17 - 24 AS1123 Datasheet - A p p l i c a t i o n I n f o r m a t i o n Constant Current In LED display applications, the AS1123 provides virtually no current variations from channel-to-channel and from AS1123-to-AS1123. This is mostly due to 2 factors: While IOUT ³ 10mA, the maximum current skew is less than ±3% between channels and less than ±3% between AS1123 devices. In the saturation region, the characteristic curve of the output stage is flat. Thus, the output current can be kept constant regardless of the variations of LED forward voltages (VF). al id 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 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: am lc s on A te G nt st il Where: REXT is the resistance of the external resistor connected to pin REXT. VREXT is the voltage on pin REXT. (EQ 1) (EQ 2) (EQ 3) lv VREXT = 1.253V IREF = VREXT/REXT (if the other end of REXT is connected to ground) IOUT TARGET = IREF*15 = (1.253V/REXT)*15 The 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) 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 Where: TJ = -40°C to +125°C (EQ 6) 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. ca 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 ni LED drivers are frequently used in switch-mode applications which normally exhibit switching noise due to parasitic inductance on the PCB. Load Supply Voltage ch Considering the package power dissipation limits, the AS1123 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. Te Note: Resistors or zener diodes can be used as a voltage reducer as shown in Figure 23 on page 19. www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 18 - 24 AS1123 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 } VLED VDROP VDROP { VF VF VDS VLED VDS AS1123 Te ch ni ca am lc s on A te G nt st il lv AS1123 al id Voltage Supply www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 19 - 24 AS1123 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 am lc s on A te G nt st il lv al id Figure 24. 24-pin QSOP Marking Figure 25. 24-pin TQFN (4x4mm) Marking Table 9. Packaging Code YYWWRZZ or YYWWXZZ WW R/X ZZ manufacturing week plant identifier free choice / traceability code ca YY Te ch ni last two digits of the current year www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 20 - 24 AS1123 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 Te ch ni ca am lc s on A te G nt st il lv al id Figure 26. 24-pin TQFN (4x4mm) Package www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 21 - 24 AS1123 Datasheet Te ch ni ca am lc s on A te G nt st il lv al id Figure 27. 24-pin QSOP Package www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 22 - 24 AS1123 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 10. Table 10. Ordering Information Description Delivery Form Package AS1123-BQFT AS1123 Constant-Current, 16-Channel LED Driver with Diagnostics Tape and Reel 24-pin TQFN (4x4mm) AS1123-BTST AS1123 Constant-Current, 16-Channel LED Driver with Diagnostics Tape and Reel 24-pin QSOP AS1123B* AS1123B Constant-Current, 16-Channel LED Driver with Diagnostics with controlled inrush Current Tape and Reel tbd *) 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 am lc s on A te G nt st il Technical Support is found at http://www.austriamicrosystems.com/Technical-Support al id Marking lv Ordering Code Te ch ni ca For further information and requests, please contact us mailto:[email protected] or find your local distributor at http://www.austriamicrosystems.com/distributor www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 23 - 24 AS1123 Datasheet Copyrights Copyright © 1997-2011, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies. al id Disclaimer lv Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems 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 life-support or life-sustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. ca am lc s on A te G nt st il The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. Headquarters ni Contact Information ch austriamicrosystems AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten, Austria Te 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 www.austriamicrosystems.com/LED-Driver-ICs Revision 1.00 24 - 24