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 Data sheet A S 112 1 16-C han ne l LED D river with D o t C o r r e c t i o n a n d G r e y s c a l e P W M 2 Key Features Greyscale PWM Control: 12-Bit (4096 Steps) The AS1121 is a 16-channel, constant current-sink LED driver. Each of the 16 channels can be individually adjusted by 4096-step greyscale PWM brightness control and 64-step constant-current sink (dot correction). Dot Correction: 6-Bit (64 Steps) al id 1 General Description Drive Capability (Constant-Current Sink): 0 to 40mA The dot correction circuitry adjusts the brightness variations between the AS1121 channels and other LED drivers. Greyscale control and dot correction circuitry are accessible via the SPI-compatible serial interface. A single external resistor sets the maximum current value of all 16 channels. LED Power Supply Voltage: up to 30V The open LED detection function indicates a broken or disconnected LED at one or more of the outputs. The overtemperature protectionflag indicates that the device is in an overtemperature condition. Output Delay for controlled Inrush Current (factory set, can be turned off) lv Supply Voltage Range: 3.1V to 3.6V am lc s on A te G nt st il SPI-Compatible Serial Interface Factory set rise- and fall-time for EMI improvement An additional power-down pin puts the AS1121 into a 40nA standbymode. PWM Clock Rate: up to 10 MHz The AS1121 is available in a 32-pin TQFN 5x5 mm package. Data Transfer Clock Rate: up to 30 MHz CMOS Level I/O Diagnostic Features 32-pin TQFN 5x5 mm Package 3 Applications The device is ideal for mono-, multi-, and full-color LED displays, LED signboards, and display backlights. Figure 1. AS1121 - Block Diagram 1 CLK IREF Max OUTn Current 24 OEN Greyscale Counter Control ch 3 Te Overtemp 12-Bit Greyscale PWM Control Dot Correction 0 Register 5 6-Bit Dot Correction Open LED Detect 22 Control 12-Bit Greyscale PWM Control Dot Correction 6 Register 11 6-Bit Dot Correction 4 OUT0 Constant Current Driver Delay OUT1 . . . Open&Short LED Detection Control Constant Current Driver 21 Greyscale 180 Register191 12-Bit Greyscale PWM Control Dot Correction 90 Register 95 6-Bit Dot Correction XERR 30 GND Delay 5 Greyscale 12 Register 23 . . Input Shift Register Constant Current Driver Open&Short LED Detection . MODE 27 Greyscale 0 Register 11 Input Shift Register Status Open LED Detect, Overtemperature, Dot Correction Data VCC 29 PD Control ni GSCLK 31 32 LD VREF = 1.24V ca 26 2 SDI Delay OUT15 Open&Short LED Detection 23 AS1121 www.austriamicrosystems.com/AS1121 SDO Revision 1.01 1 - 21 AS1121 Datasheet - P i n o u t 4 Pinout Pin Assignments 1 24 GSCLK SDI 2 23 SDO MODE 3 OUT0 4 OUT1 5 OUT2 6 OUT3 7 OUT4 8 22 XERR AS1121 21 OUT15 Thermal Pad 20 OUT14 19 OUT13 18 OUT12 33 22 XERR 23 24 26 25, 27 12,13,28 SDO GSCLK IREF VCC N/C Description Serial Data Shift Clock Serial Data Input Mode Select input with internal pulldown MODE = GND: Selects greyscale mode (see Setting Greyscale Brightness on page 14) MODE = VCC: Selects dor correction mode (see Setting Dot Correction on page 13) Constant-Current Outputs 0:7 Constant-Current Outputs 8:15 Error Output 0 = LED open detection or overtemperature condition is detected. 1 = Normal operation. Serial Data Output Greyscale Clock. Reference clock for greyscale PWM control Reference Current Terminal Power Supply Voltage This pins must not be connected Power Down 0 = normal operation mode 1 = power down mode Ground Blank Outputs 0 = OUTn outputs are controlled by the greyscale PWM control. 1 = OUTn outputs are forced off; the greyscale counter is reset. Data Latch. The internal connections are switched by pin MODE. For LD (MODE = GND), the greyscale register receives new data. For LD (MODE = VCC), the dot correction register receives new data. Thermal Pad. This pin must be connected to GND to ensure normal operation. ni ca OUT0:OUT7 OUT8:OUT15 16 OUT10 4:11 14:21 15 OUT9 MODE 14 OUT8 3 13 N/C Pin Name CLK SDI 11 OUT7 OUT5 Pin Number 1 2 12 N/C 9 Table 1. Pin Descriptions 10 OUT6 am lc s on A te G nt st il 17 OUT11 lv VCC 25 IREF 26 N/C 28 VCC 27 PD 29 GND 30 LD 32 Pin Descriptions PD ch 29 OEN 31 CLK al id Figure 2. Pin Assignments (Top View) GND 31 OEN 32 LD 33 Thermal Pad Te 30 www.austriamicrosystems.com/AS1121 Revision 1.01 2 - 21 AS1121 Datasheet - A b s o l u t e M a x i m u m R a t i n g s 5 Absolute Maximum Ratings Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Electrical Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2. Absolute Maximum Ratings Parameter Min Max Units Comments -0.3 5 V -0.3 VCC + 0.3 V VSDO, VXERR to GND -0.3 VCC + 0.3 V VOUT0 : VOUT15 to GND -0.3 30 V 50 mA -100 100 mA Output Current Electrostatic Discharge Electrostatic Discharge HBM Thermal Information Norm: JEDEC 78 am lc s on A te G nt st il Input Current (latch-up immunity) lv VCC to GND All other pins to GND al id Electrical Parameters +/- 2 Junction to ambient thermal resistance kV Norm: MIL 883 E method 3015 37 °C/W For more information about thermal metrics, see application note AN01 Thermal Characteristics. +150 ºC +150 ºC Temperature Ranges and Storage Conditions Junction Temperature Storage Temperature Range -55 Package Body Temperature Humidity non-condensing 5 ºC 85 % 3 Represents a max. floor life time of 168h Te ch ni ca Moisture Sensitive Level +260 The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD020“Moisture/Reflow Sensitivity Classification for NonHermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). www.austriamicrosystems.com/AS1121 Revision 1.01 3 - 21 AS1121 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 VCC = +3.1V to +3.6V, Typical values are at TAMB = +25°C, VCC = 3.3V (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 Min TAMB Operating Temperature Range -40 TJ Operating Junction Temperature -40 Supply Voltage 3.1 Typ Input Supply Supply Current ICC All outputs off, RIREF = 1kΩ 8.5 All outputs on, RIREF = 1kΩ 15 All outputs off, RIREF = 10kΩ +85 °C +125 °C 3.6 V 15 20 2 4 3 5 am lc s on A te G nt st il All outputs on, RIREF = 10kΩ VIN = VCC or GND; Pins OEN, GSCLK, CLK, SDI, LD, PD Input Current I -1 50 -1 Power Down Current IPD Output VOUT Voltage Applied to Output (OUT0:OUT15) ICOC Constant Output Current ΔICOC 1.5 Line Regulation ch Load Regulation V 44 mA ±1 VOUT = 1.5V, RIREF = 10kΩ, OUT0:OUT15 ±1.5 Device to device, average current from OUT0:OUT15, RIREF = 1kΩ ±1 Device to device, average current from OUT0:OUT15, RIREF = 10kΩ ±1 All outputs off, VOUT = 30V, RIREF = 1kΩ, OUT0:OUT15 20 VOUT = 1V, RIREF = 1kΩ OUT0:OUT15 ±1 ±2.5 VOUT = 1V, RIREF = 10kΩ OUT0:OUT15 ±0.2 ±2.5 VOUT = 1.5V to 4V, RIREF = 1kΩ, OUT0:OUT15 ±0.1 ±0.4 VOUT = 1.5V to 4V, RIREF = 10kΩ, OUT0:OUT15 ±0.01 ±0.4 ca ΔILNR ni Leakage Output Current 40 nA 30 VOUT = 1.5V, RIREF = 1kΩ, OUT0:OUT15 Constant Output Current Error ILEAK 36 µA 1 40 All outputs on, VOUT = 1.5V, RIREF = 1kΩ mA 1 VIN = VCC; pin MODE VIN = GND; pin MODE ΔILDR Unit lv VCC Max al id Symbol % nA %/V %/V Logic Levels High-Level Input Voltage 0.8 x VCC VCC V VIL Low-Level Input Voltage GND 0.2 x VCC V VOH High-Level Output Voltage IOH = -1mA, SDO VOL Low-Level Output Voltage IOL = 1mA, SDO, XERR IOH High-Level Output Current VCC = 5 V at SDO Te VIH www.austriamicrosystems.com/AS1121 Revision 1.01 VCC -0.5 V 0.5 -1.0 V mA 4 - 21 AS1121 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 Min IOL Low-Level Output Current VCC = 5 V at SDO, XERR 1.0 VLOD LED Open Detection Threshold VIREF Reference Voltage Output RIREF = 1kΩ 1.23 Typ Max Unit mA 0.3 0.4 V 1.27 1.32 V TTWF Thermal Warn Flag Threshold 125 TTEF Thermal Error Flag Threshold 150 ºC ºC lv Timing Characteristics al id Thermal Protection VCC = +3.1V to +3.6V, TAMB = -40°C to +85ºC. Typical values are at TAMB = +25°C, VCC = 3.3V (unless otherwise specified). am lc s on A te G nt st il Table 4. Output Tming Characteristics Symbol Parameter tR0 Rise Time 1 tR1 tF0 tF1 Conditions Fall Time 1 tPD0 Min SDO 8 OUTn, DC = 3FHEX, RIREF = 1kΩ 25 SDO 8 OUTn, DC = 3FHEX, RIREF = 1kΩ 25 CLK, SDO Max Unit ns ns 2 2 tPD1 Propagation Delay Time OUT0, OUT1, OUT2, OUT3 , RIREF = 1kΩ, turn ON delay 15 ns 25 ns 2 OUT0, OUT1, OUT2, OUT3 , RIREF = 1kΩ, turn OFF delay tPD2 OUT4, OUT5, OUT6, OUT7 Average Output Delay Time (can be turend off on request) ca tD Typ 2 OUT8, OUT9, OUT10, OUT11 2 OUT12, OUT13, OUT14, OUT15 2 ni 1. Value can be factory trimmed for EMI improvement 2. See Figure 24 on page 16. Interface Characteristics ch VCC = +3.1V to +3.6V, TAMB = -40°C to +85ºC. Typical values are at TAMB = +25°C, VCC = 3.3V (unless otherwise specified). Table 5. Serial Interface Timing Characteristics Parameter Conditions fCLK Data Shift Clock Frequency CLK fGSCLK Greyscale Clock Frequency GSCLK Te Symbol 1 tWH0/tWL0 CLK Pulse Duration CLK = 1/0 tWH1/tWL1 GSCLK Pulse Duration GSCLK = 1/0 tWH2 LD Pulse Duration LD = 1 tWH3 OEN Pulse Duration OEN = 1 www.austriamicrosystems.com/AS1121 Revision 1.01 Min 1 2 2 Typ Max Unit 30 MHz 5 MHz 16 ns tbd ns 20 ns 20 ns 5 - 21 AS1121 Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s Table 5. Serial Interface Timing Characteristics tERR Error Detection Duration SDI, CLK tSU1 CLK, LD Setup Time Min LD = 1, OEN = 0 tSU0 tSU2 4 3 Typ Max 1000 MODE, CLK 5 4 tSU4 OEN, GSCLK tH0 CLK, SDI tH1 LD, CLK ns 12 12 2 12 3 12 1 12 CLK, MODE 4 12 ns am lc s on A te G nt st il tH3 LD, MODE tH4 Unit 12 MODE, LD Hold Time 3 12 tSU3 tH2 4 OEN, GSCLK ns 12 2 12 See Figure 20 on page 13. See Figure 24 on page 16. See Figure 18 on page 11 See Figure 22 on page 14. See Figure 17 on page 10. Te ch ni ca 1. 2. 3. 4. 5. Conditions al id Parameter lv Symbol www.austriamicrosystems.com/AS1121 Revision 1.01 6 - 21 AS1121 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 TAMB = +25°C, VCC = 3.3V (unless otherwise specified) Figure 3. Constant Output Current vs. Output Voltage Figure 4. Constant Output Current vs. Output Voltage 40 35 Icoc = 30mA (1.33kΩ) 30 25 Icoc = 20mA (1.96kΩ) 20 15 Icoc = 10mA (4.02kΩ) 10 Icoc =4mA (10kΩ) 5 Icoc = 1mA (40.2kΩ) 0 45 Icoc = 40mA (1kΩ) al id Icoc = 40mA (1kΩ) 40 35 Icoc = 30mA (1.33kΩ) 30 25 Icoc = 20mA (1.96kΩ) lv 45 Constant Output Current (mA) 50 20 15 Icoc = 10mA (4.02kΩ) 10 Icoc =4mA (10kΩ) am lc s on A te G nt st il Constant Output Current (mA) 50 5 Icoc = 1mA (40.2kΩ) 0 0 1 2 3 4 5 6 7 8 9 10 0 0.25 0.5 0.75 Output Voltage (V) Figure 5. Constant Output Current vs. VOUT; RIREF = 1kΩ 1.5 1.75 2 Figure 6. Constant Output Current vs. VOUT; RIREF = 1kΩ 40 35 30 25 20 15 10 Constant Output Current (mA) 45 -40°C +25°C 5 +85°C 0 0 1 2 3 4 5 6 7 8 45 40 35 30 25 20 15 10 -40°C +25°C 5 +85°C 0 9 10 0 0.5 Output Voltage (V) Constant Output Current (mA) Te 41 40.5 40 39.5 39 -40 -15 10 35 60 85 4.15 4.1 4.05 4 3.95 3.9 -40 Ambient Temperature (°C) www.austriamicrosystems.com/AS1121 2 4.2 ch 41.5 1.5 Figure 8. ICOC vs. Temp.; RIREF = 10kΩ, VOUT = 1.5V ni 42 1 Output Voltage (V) Figure 7. ICOC vs. Temp.; RIREF = 1kΩ, VOUT = 1.5V Constant Output Current (mA) 1.25 50 ca Constant Output Current (mA) 50 1 Output Voltage (V) -15 10 35 60 85 Ambient Temperature (°C) Revision 1.01 7 - 21 AS1121 Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s Figure 10. ICOC vs. Dot Correction; VOUT = 1.5V 40 50 35 45 25 20 15 10 5 0 RIREF = 10kOhm 40 35 30 25 al id 30 RIREF = 1kOhm 20 15 10 5 0 0 5 10 15 20 25 30 35 40 0 9 18 Figure 11. Supply Current vs. Temp.; RIREF = 1kΩ, VOUT = 1.5V 25 27 36 45 54 63 Dot Correction am lc s on A te G nt st il R IREF (kOhm) lv Constant Output Current (mA) Constant Output Current (mA) Figure 9. ICOC vs. RIREF; VOUT = 1.5V Figure 12. ΔICOC vs. Constant Output Current average 4 all channels on, DC=63, OEN=LOW 3.5 Vout = 1.5V Vout = 3.0V all channels off DC=0, OEN=HIGH 3 all channels off , DC=63 OEN=HIGH delta Icoc (%) Supply Current (mA) all channels off , DC=0, OEN=LOW 20 15 10 2.5 2 1.5 1 5 0.5 0 -40 0 -15 10 35 60 85 0 Figure 13. ΔICOC vs. Temp.; RIREF = 1kΩ 1.75 delta Icoc (%) delta Icoc (%) 25 30 35 40 1.5 1 Te 20 1.75 1.25 0.75 0.5 1.25 1 0.75 0.5 Vout = 1.5V 0.25 0 -40 15 2 ch 1.5 10 Figure 14. ΔICOC vs. Temp.; RIREF = 10kΩ ni 2 5 Constant Output Current average (mA) ca Ambient Temperature (°C) -15 10 35 60 85 0 -40 Ambient Temperature (°C) www.austriamicrosystems.com/AS1121 Vout = 1.5V 0.25 Vout = 3.0V Vout = 3.0V -15 10 35 60 85 Ambient Temperature (°C) Revision 1.01 8 - 21 AS1121 Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s Figure 15. LED Open Detection Threshold vs. Temperature Figure 16. ICOC vs. Supply Voltage; RIREF = 1kΩ 41 36 34 32 30 -40 40.75 40.5 40.25 40 al id 38 39.75 39.5 39.25 39 -15 10 35 60 85 3.1 3.2 3.3 3.4 3.5 3.6 Supply Voltage (V) Te ch ni ca am lc s on A te G nt st il Ambient Temperature (°C) lv Constant Output Current (mA) LED Open Detection Threshold (mV) 40 www.austriamicrosystems.com/AS1121 Revision 1.01 9 - 21 AS1121 Datasheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description Serial Interface The AS1121 features a versatile 3-pin (CLK, SDI, and SDO) serial interface, which can be connected to microcontrollers or digital signal processors in various configurations. al id The rising edge of the CLK signal shifts data from pin SDI to the internal register. After all data is clocked in, the serial data is latched into the internal registers at the rising edge of the LD signal. Note: All data is clocked in with the MSB first. Multiple AS1121 devices can be cascaded by connecting the SDO pin of one device with pin SDI of the next device (see Figure 25 on page 17). The SDO pin can also be connected to the microcontroller to receive status information from the AS1121. The serial data format is 96-bit or 192bit wide, depending on mode of the device (see LD on page 2). MODE Greyscale Mode Data Input Cycle tH3 LD SDI DCn-1 LSB DCn MSB SDO 1 DCn-1 MSB DCn-1 MSB-1 tSU3 DCn LSB tH2 CLK Dot Correction Mode Data Input Cycle am lc s on A te G nt st il Dot Correction Mode Data Input Cycle lv Figure 17. Serial Data Input Timing Diagram 96 DCn-1 LSB tH3 GSn MSB GSn LSB tSU2 tSU2 1 DCn MSB DCn-1 MSB-1 DCn+1 MSB 192 X X 1 SID MSB 2 X ca Error Information Output ni The open-drain output pin XERR indicates if the device is in one of the two error conditions: overtemperature flag or open LED detect. During normal operation, the internal transistor connected to pin XERR is turned off and the voltage on XERR is pulled up to VCC through an external pullup resistor. ch If an overtemperature or open LED condition is detected, the internal transistor is switched on, and XERR is pulled to GND. Because XERR is an open-drain output, multiple AS1121 devices can be ORed together and pulled up to VCC with a single pullup resistor (see Figure 25 on page 17). This reduces the number of signals needed to report a system error. Te To differentiate the overtemperature flag from the open LED detect flag from pin XERR, the open LED detect flag can be masked out by setting OEN = 1 (see Table 6). www.austriamicrosystems.com/AS1121 Revision 1.01 10 - 21 AS1121 Datasheet - D e t a i l e d D e s c r i p t i o n Table 6. XERR Truth Table Error Condition T e m p TJ < TTEF TJ > TTEF OEN Mode Status XERR OUTn > VLOD 0 Don't Care 0 0 0 1 normal OUTn < VLOD 0 Don't Care 1 0 0 0 open error OUTn > VLOD 1 Don't Care 0 0 0 0 temp. error 0 open & temp. error OUTn < VLOD 1 Don't Care 1 0 0 TJ > TTEF Don't Care 0 Don't Care Don't Care 1 0 1 normal TJ < TTEF Don't Care 1 Don't Care Don't Care 1 0 0 temp error TJ > TTWF Don't Care Don't Care 0 Don't Care 1 1 1 normal TJ < TTWF Don't Care Don't Care 1 Don't Care 1 1 0 temp. warn am lc s on A te G nt st il Overtemperature Error/Warning Flags lv O p e n OUTn Voltage Selected Mode al id Temp. Error Information Thermal Thermal Open LED Warning Error Flag Detect Flag The AS1121 provides a overtemperature circuit to indicate that the device is in an overtemperature condition. If the device junction temperature (TJ) exceeds the threshold temperature (150°C typ), the overtemperature circuit trips and pulls XERR to ground. The overtemperature flag status can be read out from the AS1121 status register. To prevent an overtemperature condition the AS1121 offers an temperature warning flag at 125°C typical. This flag can be used to take precautions (e.g. start an external cooling) against a overtemperature condition. Open LED Detection The AS1121 integrated open LED detection circuit reports an error if any of the 16 LEDs is open or disconnected from the circuit. The open LED detection circuit trips when the error detection is activated and the voltage at OUTn is less than VLOD. Note: The voltage at each OUTn is sampled 1 µs after being switched on. Please refer to Figure 18 on page 11. The open LED detection circuit also pulls XERR to GND when tripped. The open LED status of each channel can also be read out from the AS1121 status information data (SID) during a greyscale data input cycle. Figure 18. Error Detection Timing (GS=FFFFHEX, DC=3FHEX) ca LD tERR ni OEN ch GSCLK Te SID LODn Error Detection Start LODn+1 Error Detection End Note: The rising edge of LD latches new data into the internal registers depending on the logic level of the pin MODE. If the pin MODE is tied GND, the greyscale registers are updated. If the pin MODE is tied to VCC, the dot correction registers are updated. www.austriamicrosystems.com/AS1121 Revision 1.01 11 - 21 AS1121 Datasheet - D e t a i l e d D e s c r i p t i o n OUTn Enable All OUTn channels can be collectively switched off with one signal. When OEN is set to 1, all OUTn channels are disabled, regardless of the device logic operations. The greyscale counter is also reset when OEN is set to 1. When OEN is set to 0, all OUTn channels are in normal operation. OEN OUT0:OUT15 0 Normal Operation 1 Disabled al id Table 7. Pin OEN Truth Table Setting Maximum Channel Current Where: VIREF RIREF x 31.5 (EQ 1) am lc s on A te G nt st il IMAX = lv The maximum output current per channel is programmed by a single resistor, RIREF, which is placed between pin IREF and GND. The voltage on pin IREF is set by an internal band gap VIREF (1.27V typ). The maximum channel current is equivalent to the current flowing through RIREF multiplied by a factor of 31.5. The maximum output current is calculated as: VIREF = 1.27V; RIREF = User-selected external resistor. Power Dissipation To ensure proper operation of the device, the total power dissipation of the AS1121 must be below the power dissipation rating of the device package. Total power dissipation is calculated as: PD = (VCC x ICC) + (VOUT x IMAX x n x Where: DCn dPWM) 63 (EQ 2) ni ca VCC is the device supply voltage; ICC is the device supply current; VOUT is the device OUTn voltage when driving LED current; IMAX is the LED current adjusted by RIREF; DCn is the maximum dot correction value for OUTn; n is the number of OUTn driving LED at the same time; dPWM is the duty cycle defined by pin OEN or the greyscale PWM value. Operating Modes ch The AS1121 operates in two modes (see Table 8). Greyscale operating mode (see Figure 22 on page 14) and the shift registers are in reset state at power-up. Table 8. Operating Modes Input Shift Register Operating Mode 0 192-bit Greyscale PWM Mode 1 96-bit Dot Correction Data Input Mode Te Mode www.austriamicrosystems.com/AS1121 Revision 1.01 12 - 21 AS1121 Datasheet - D e t a i l e d D e s c r i p t i o n Setting Dot Correction The AS1121 can perform independent fine-adjustments to the output current of each channel, i.e., dot correction. Dot correction is used to adjust brightness deviations of LEDs connected to the output channels (OUT0:OUT15). The device powers up with the following default seetings: DC = 63 and GS = 4095. The 16 channels can be individually programmed with a 6-bit word. The channel output can be adjusted in 64 steps from 0 to 100% of the maximum output current (IMAX). The output current for each OUTn channel can be calculated as: DCn 63 al id IOUTn = IMAX x (EQ 3) Where: lv IMAX is the maximum programmable output current for each output; DCn is the programmed dot correction value for output (DCn = 0 to 63); n = 0 to 15 am lc s on A te G nt st il Dot correction data are simultaneously entered for all channels. The complete dot correction data format consists of 16 x 6-bit words, which forms a 96-bit serial data packet (see Figure 19). Channel data is put on one by one, and the data is clocked in with the MSB first. Figure 19. Dot Correction Data Packet Format MSB 95 DC15.5 ... 90 89 DC15.0 DC14.5 DC OUT15 ... 6 5 DC1.0 DC0.5 DC OUT14:DC OUT1 ... LSB 0 DC0.0 DC OUT0 Figure 20. Dot Correction Data Input Timing Diagram Dot Correction Mode Data Input Cycle n VCC MODE GND DCn-1 LSB DCn MSB DCn MSB-1 DCn MSB-2 DCn LSB+1 ca SDI Dot Correction Mode Data Input Cycle n +1 tSU0 CLK DCn LSB DCn+1 MSB DCn+1 MSB-1 tWH0 2 1 ni 1 95 96 1 2 tWL0 DCn-1 MSB DCn-1 MSB-1 ch SDO DCn-1 MSB-2 DCn-1 LSB+1 DCn-1 LSB tSU1 DCn MSB-1 DCn MSB tWH2 DCn MSB-2 tH1 Te LD www.austriamicrosystems.com/AS1121 Revision 1.01 13 - 21 AS1121 Datasheet - D e t a i l e d D e s c r i p t i o n Setting Greyscale Brightness The brightness of each channel output can be adjusted using a 12 bits-per-channel PWM control scheme which results in 4096 brightness steps, from 0% to 100% brightness. The brightness level for each output is calculated as: GSn x 100 4095 %Brightness = (EQ 4) al id Where: GSn is the programmed greyscale value for OUTn (GSn = 0 to 4095); n = 0 to 15 greyscale data for all outputs. The device powers up with the following default seetings: GS = 4095 and DC = 63. lv The input shift register shifts greyscale data into the greyscale register for all channels simultaneously. The complete greyscale data format consists of 16 x 12 bit words, which forms a 192-bit wide data packet (see Figure 21). Note: The data packet must be clocked in with the MSB first. MSB 191 ... GS15.11 am lc s on A te G nt st il Figure 21. Greyscale Data Packet Format 180 179 GS15.0 GS14.11 GS OUT15 ... 12 11 GS1.0 GS0.11 GS OUT14:GS OUT1 ... LSB 0 GS0.0 GS OUT0 When pin MODE is tied to GND, the AS1121 enters greyscale data input mode. The device switches the input shift register to 192-bit width. After all data is clocked in, the rising edge of the LD signal latches the data into the greyscale register (see Figure 22). All greyscale data in the input shift register is replaced with status information data (SID) after latching into the greyscale register. Figure 22. Greyscale Data Input Timing Diagram Dot Correction Mode Data Input Cycle Following Greyscale Mode Data Input Cycle ca MODE 1st Greyscale Mode Data Input Cycle After Dot Correction Input tH3 tSU3 tH3 GSn MSB DCn-1 LSB ch SDI ni LD GSn LSB tH2 tSU2 CLK Te SDO DCn-1 MSB-1 DCn-1 MSB tSU1 tH0 96 1 x www.austriamicrosystems.com/AS1121 GSn+1 MSB tPD0 192 x x GSn+1 LSB 1 SIDn MSB Revision 1.01 192 SIDn MSB-1 SIDn MSB-2 SIDn LSB SIDn MSB 14 - 21 AS1121 Datasheet - D e t a i l e d D e s c r i p t i o n Status Information Data (SID) The AS1121 contains an integrated status information register, which can be accessed in greyscale mode (MODE = GND). Once the LD signal latches the data into the greyscale register, the input shift register data is replaced with status information data (see Figure 23). Figure 23. Status Information Data Packet Format MSB LSB ... 176 175 174 LOD0 TEF TWF Open LED Detect Data 167 X DC15.5 Overtemperature Flag DC Values Bit # 167:72 71:32 31:16 15:0 71 DC0.0 X ... 31:16 15:0 LOD 0 Description Dot Correction Readback (16 x 6 Bit) reserved LED Open Detection (Optional, same as bits 176:191), LOD reserved am lc s on A te G nt st il Description reserved Temperature Error Flag (TEF, 150ºC, typ) Temperature Warning Flag (TWF, 125ºC, typ) reserved ... 72 Te ch ni ca Bit # 191:176 175 174 173:168 ... 168 lv 191 LOD15 al id Open LED and overtemperature flags as well as the dot-correction registers can be read out at pin SDO. The status information data packet is 192 bits wide. Bits 191:176 and 31:16 contain the open LED detection status of each channel (either 191:176 or 31:16 can be used for readout). Bit 175 contains the thermal error flag status. Bits 167:72 contain the data of the dot-correction register. Bit 15:0 contains the LED shorted flags. The remaining bits are reserved. The complete status information data packet is shown in Figure 23. www.austriamicrosystems.com/AS1121 Revision 1.01 15 - 21 AS1121 Datasheet - D e t a i l e d D e s c r i p t i o n Greyscale PWM Operation The falling edge of the OEN signal initiates a greyscale PWM cycle. The first GSCLK pulse after the falling edge of OEN increments the greyscale counter by one and switches on any OUTn whose greyscale value does not equal zero. Each subsequent rising edge of GSCLK increments the greyscale counter by one. The AS1121 compares the greyscale value of each OUTn channel with the greyscale counter value. All OUTn whose greyscale values equal the counter values are switched off. A OEN = 1 signal after 4096 GSCLK pulses resets the greyscale counter to zero and completes a greyscale PWM cycle (see Figure 24). all LED’s ON al id Figure 24. Greyscale PWM Cycle Timing Diagram Greyscale PWM Cycle n+1 Greyscale PWM Cycle n all LED’s OFF tWL1 tWH1 GSCLK tH4 2 4096 3 tW1 tPD1 tPD2 tPD2+td OUT4:OUT7 Current OUT8:OUT11 Current tPD2 am lc s on A te G nt st il tPD2 tSU4 tWH3 1 OUT0:OUT3 Current lv OEN tPD2+2xtd tPD2+3xtd OUT12:OUT15 Current XERR Output Delay ca To minimize the ripple on the inrush current, the outputs are delayed and are not switching at the same time. The 16 channels of the AS1121 are combined in groups of 4. The channels within the groups OUT0:OUT3, OUT4:OUT7, OUT8:OUT11, OUT12:OUT15 are switching at the same time. Between the 4 groups a delay of td = 25ns (typ.) is implemented. On request this delay can be turned off (see Ordering Information on page 20). Te ch ni To increase the EMI performance the rising and falling edges of the OUTn signals are symmetrical (tR = tF = 25ns). The rise- and fall-times are factory set and can be changed on request. For further information and requests, please contact us mailto:[email protected]. www.austriamicrosystems.com/AS1121 Revision 1.01 16 - 21 AS1121 Datasheet - D e t a i l e d D e s c r i p t i o n Serial Data Transfer Rate Figure 25 shows a cascaded arrangement AS1121 devices connected to a controller, building a basic module of an LED display system. Figure 25. Cascaded Configuration VLED VLED VLED ... 100kΩ OUT0 VLED ... OUT15 OUT0 ... OUT15 SIN SDI SDO XERR SDI SDO VCC XERR VCC XERR CLK VCC LD VCC CLK AS1121 LD GSCLK VCC 100nF GSCLK MODE GND MODE GSCLK MODE VCC 100nF GND am lc s on A te G nt st il OEN AS1121 lv CLK LD al id VCC OEN SOUT OEN IREF Controller IREF 6 The maximum number of cascading AS1121 devices depends on the application system and is in the range of 40 devices. The minimum frequency needed can be calculated by the following equations: fGSCLK = 4096 x fUPDATE Where: (EQ 5) fGSCLK is the minimum frequency needed for GSCLK; fUPDATE is the update rate of whole cascaded system. ca fCLK = 193 x fUPDATE x n Where: (EQ 6) ni fCLK is the minimum frequency needed for CLK and SIN; fUPDATE is the update rate of whole cascaded system; Te ch n is the number of cascaded of AS1121 devices. www.austriamicrosystems.com/AS1121 Revision 1.01 17 - 21 AS1121 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 9 Package Drawings and Markings Figure 27. Packaging Code YYWWIZZ YY WW manufacturing week I plant identifier ZZ free choice / traceability code Te ch ni ca am lc s on A te G nt st il last two digits of the current year lv al id Figure 26. 32-pin TQFN 5x5 mm Marking www.austriamicrosystems.com/AS1121 Revision 1.01 18 - 21 AS1121 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 28. 32-pin TQFN 5x5 mm Package www.austriamicrosystems.com/AS1121 Revision 1.01 19 - 21 AS1121 Datasheet - O r d e r i n g I n f o r m a t i o n 10 Ordering Information The device is available as the standard products shown in Table 9. Table 9. Ordering Information Marking Description Delivery Form Package AS1121-BQFT AS1121 16-Channel LED Driver with Dot Correction and Greyscale PWM Tape and Reel 32-pin TQFN 5x5 mm AS1121B-BQFT* AS1121B 16-Channel LED Driver with Dot Correction and Greyscale PWM without Output Delay Tape and Reel 32-pin TQFN 5x5 mm 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/Technical-Support Te ch ni ca am lc s on A te G nt st il For further information and requests, please contact us mailto:[email protected] or find your local distributor at http://www.austriamicrosystems.com/distributor lv *) on request al id Ordering Code www.austriamicrosystems.com/AS1121 Revision 1.01 20 - 21 AS1121 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/AS1121 Revision 1.01 21 - 21