AS1112 D a ta s h e e t 16-Channel LED Driver with Dot Correction and Greyscale PWM 1 General Description 2 Key Features ! The AS1112 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). ! The dot correction circuitry adjusts the brightness variations between the AS1112 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. The open & short LED detection function indicates a broken, shorted or disconnected LED at one or more of the outputs. The overtemperature flag indicates that the device is in an overtemperature condition. Table 1. Standard Products Model Power-Down TEST pin AS1112 Yes Connect to GND AS1112B No Connect to VCC 16 Channels Greyscale PWM Control: 12-Bit (4096 Steps) ! Dot Correction: 6-Bit (64 Steps) ! Drive Capability (Constant-Current Sink): 0 to 80mA ! LED Power Supply Voltage: Up to 15V ! Supply Voltage Range: 3.0 to 5.5 V ! SPI-Compatible Serial Interface ! Controlled In-Rush Current ! Data Transfer & PWM Clock Rate: up to 30 MHz ! CMOS Level I/O ! Diagnostic Features - LED Open/Short Detection - Overtemperature Flag ! 32-pin TQFN 5x5 mm Package An additional power-down pin puts the AS1112 into a 40nA standby-mode. 3 Applications The AS1112 is available in a 32-pin TQFN 5x5 mm package. The device is ideal for mono-, multi-, and full-color LED displays, LED signboards, and display backlights. Figure 1. Block Diagram 1 CLK 26 IREF Max OUTn Current 2 SDI Greyscale Counter Control Greyscale 0 Register 11 12-Bit Greyscale PWM Control Dot Correction 0 Register 5 6-Bit Dot Correction Input Shift Register Greyscale 12 Register 23 12-Bit Greyscale PWM Control Dot Correction Register 11 6-Bit Dot Correction 6 . MODE Open LED Detect 22 Constant Current Driver Input Shift Register Delay x1 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 OUT0 5 3 Thermal Flag Delay x0 Open&Short LED Detection Control Status Open LED Detect, Overtemperature Flag, Dot Correction Data 27 Constant Current Driver 4 Control OEN VCC 29 PD VREF = 1.24V 24 GSCLK 31 32 LD Delay x15 OUT15 Open&Short LED Detection 23 AS1112 www.austriamicrosystems.com SDO Revision 1.06 1 - 18 AS1112 Datasheet - P i n o u t 4 Pinout Pin Assignments Figure 2. Pin Assignments (Top View) XTEST 25 IREF 26 N/C 28 VCC 27 N/C 29 GND 30 LD 32 OEN 31 TEST 25 IREF 26 N/C 28 VCC 27 PD 29 GND 30 LD 32 OEN 31 CLK 1 24 GSCLK CLK 1 24 GSCLK SDI 2 23 SDO SDI 2 23 SDO MODE 3 22 XERR MODE 3 OUT0 4 21 OUT15 OUT0 4 OUT1 5 20 OUT14 OUT1 5 OUT2 6 19 OUT13 OUT2 6 OUT3 7 18 OUT12 OUT3 7 OUT4 8 17 OUT11 OUT4 8 AS1112 Thermal Pad 33 22 XERR AS1112B 21 OUT15 Thermal Pad 20 OUT14 19 OUT13 18 OUT12 33 17 OUT11 16 OUT10 15 OUT9 14 OUT8 13 N/C 11 OUT7 OUT5 12 N/C 9 10 OUT6 16 OUT10 15 OUT9 14 OUT8 13 N/C 11 OUT7 OUT5 12 N/C 9 10 OUT6 Pin Descriptions Table 2. Pin Descriptions Pin Number 1 2 3 4:11 14:21 22 23 24 25 26 27 12,13,28 29 30 31 32 33 Pin Name CLK SDI 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 12). MODE MODE = VCC: Selects dot correction mode (see Setting Dot Correction on page 11). OUT0:OUT7 Constant-Current Outputs 0:7 OUT8:OUT15 Constant-Current Outputs 8:15 Error Output 0 = LED open detection or overtemperature condition is detected. XERR 1 = Normal operation. Serial Data Output SDO Greyscale Clock. Reference clock for greyscale PWM control GSCLK Test Pin This pin must be connected to GND (AS1112) to ensure normal operation. TEST Test Pin This pin must be connected to VCC (AS1112B) to ensure normal operation. XTEST Reference Current Terminal IREF Power Supply Voltage VCC This pin must not be connected. N/C Power Down input with internal pulldown (AS1112) 0 = normal operation mode PD 1 = powerdown mode Not Connected (AS1112B) N/C Ground GND Blank Outputs 0 = OUTn outputs are controlled by the greyscale PWM control. OEN 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. LD For LD (MODE = VCC), the dot correction register receives new data. Thermal Pad Thermal Pad. This pin must be connected to GND to ensure normal operation. www.austriamicrosystems.com Revision 1.06 2 - 18 AS1112 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 3 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 Recommended Operating Conditions on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 3. Absolute Maximum Ratings Parameter Min Max Units Input Voltage Range to GND 0.3 6 V Output Current (DC) 90 mA Input Voltage Range -0.3 VCC + 0.3 V Output Voltage Range VSDO, VXERR to GND -0.3 VCC + 0.3 V Output Voltage Range VOUT0: VOUT15 to GND -0.3 15 V 2 kV ESD Rating Comments JEDEC 22-A114 Human Body Model Storage Temperature Range -55 +150 ºC Operating Ambient Temperature Range -40 +85 ºC 23 ºC/W on 4-Layer PCB ºC The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD-020D “Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). 32-pin TQFN 5x5 mm Package Thermal Impedance Package Body Temperature www.austriamicrosystems.com +260 Revision 1.06 3 - 18 AS1112 Datasheet - R e c o m m e n d e d O p e r a t i n g C o n d i t i o n s 6 Recommended Operating Conditions Table 4. DC Characteristics Symbol Parameter Conditions Min Typ Max Unit VCC Supply Voltage 5.5 V VOUT Voltage Applied to Output (OUT0:OUT15) 15 V VIH High-Level Input Voltage 0.8 x VCC VCC V VIL Low-Level Input Voltage GND 0.2 x VCC V IOH High-Level Output Current VCC = 5 V at SDO -1.0 mA IOL Low-Level Output Current VCC = 5 V at SDO, XERR 1.0 mA ICOC Constant Output Current OUT0:OUT15 3 80 mA Max Unit 30 MHz 30 MHz Table 5. AC Characteristics – VCC = 3 V to 5.5 V, TAMB = -40 to 85°C (unless otherwise noted) Symbol Parameter Conditions fCLK Data Shift Clock Frequency CLK fGSCLK Greyscale Clock Frequency GSCLK 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 SDI, CLK tSU1 CLK, LD Setup Time 2 1 tSU0 tSU2 Min 2 3 3 ns 16 ns 20 ns 20 ns 12 MODE, CLK 4 4 MODE, LD tSU4 OEN, GSCLK tH0 CLK, SDI tH1 LD, CLK Hold Time 16 12 tSU3 tH2 Typ 12 12 2 12 3 12 1 12 CLK, MODE 4 4 tH3 LD, MODE tH4 OEN, GSCLK ns 12 ns 12 2 12 1. See Figure 10 on page 12. 2. See Figure 14 on page 14. 3. See Figure 12 on page 13. 4. See Figure 7 on page 8. www.austriamicrosystems.com Revision 1.06 4 - 18 AS1112 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 7 Electrical Characteristics VCC = +3.0 to +5.5V, TAMB = -40 to +85ºC. Typical values are at TAMB = 25°C, VCC = 5V (unless otherwise specified). Table 6. Electrical Characteristics Symbol Parameter Condition Min VOH High-Level Output Voltage IOH = -1mA, SDO VCC 0.5 VOL Low-Level Output Voltage IOL = 1mA, SDO, XERR VIN = VCC or GND; Pins OEN, TEST, GSCLK, CLK, SDI, LD I Input Current Supply Current Max 0.5 -1 -1 All outputs off, RIREF = 10kΩ 1.2 3 All outputs off, RIREF = 1.3kΩ 4 10 All outputs on, RIREF = 1.3kΩ 15 20 All outputs on, RIREF = 640Ω 30 40 Power Down Current ICOC Constant Output Current All outputs on, VOUT = 2V, RIREF = 640Ω ILEAK Leakage Output Current All outputs off, VOUT = 15V, RIREF = 640Ω, OUT0:OUT15 20 VOUT = 2V, RIREF = 640Ω, OUT0:OUT15 ±3 ±4.5 VOUT = 2V, RIREF = 480Ω, OUT0:OUT15 ±3 ±4.5 Device to device, average current from OUT0:OUT15, RIREF = 1920Ω (20 mA) ±3 ±4.5 Device to device, average current from OUT0:OUT15, RIREF = 480Ω (80 mA) ±3 ±4.5 VOUT = 2V, RIREF = 640Ω OUT0:OUT15 ±1 ±2.5 VOUT = 2V, RIREF = 480Ω OUT0:OUT15 ±1 ±2.5 VOUT = 2 to 4V, RIREF = 640Ω, OUT0:OUT15 ±0.1 ±0.5 VOUT = 2 to 4V, RIREF = 480Ω, OUT0:OUT15 ±0.1 ±0.5 ΔILNR ΔILDR Constant Current Error Line Regulation Load Regulation 40 TTEF Thermal Error Flag Threshold Junction temperature TTWF Thermal Warn Flag Threshold Junction temperature VLSD LED Short Detection Threshold VLOD LED Open Detection Threshold VIREF Reference Voltage Output 61 mA nA 69 mA nA % %/V %/V 1 150 ºC 1 125 ºC 3.6 V VCC = 5V RIREF = 640Ω µA 1 IPD ΔICOC V 1 100 54 Unit V VIN = VCC; pin MODE, PD VIN = GND; pin MODE, PD ICC Typ 1.20 0.3 0.4 V 1.24 1.28 V 1. Specified by design. Not tested. www.austriamicrosystems.com Revision 1.06 5 - 18 AS1112 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 VCC = +3.0 to +5.5V, TAMB = -40 to +85ºC. Typical values are at TAMB = 25°C, VCC = 5V (unless otherwise specified). Table 7. Switching Characteristics Symbol Parameter Conditions tR0 tR1 Rise Time tF1 8 OUTn, DC = 3FHEX 20 SOUT 8 OUTn, DC = 3FHEX 20 1 tPD0 CLK, SDO tPD1 OEN, OUT0 Propagation Delay Time tPD2 2 Average Output Delay Time OUTn, OUTn+1 Unit ns ns 30 ns 2 GSCLK, OUT0 Max 15 OUTn, XERR (includes error detection time, see Figure 8 on page 10) tPD3 tD Typ SDO tF0 Fall Time Min 1000 2 30 2 30 ns 1. See Figure 12 on page 13. 2. See Figure 14 on page 14. Dissipation Ratings Table 8. Dissipation Ratings Package Type Power Rating (TAMB < 25ºC) Derating Factor above 25ºC Power Rating (TAMB = 70ºC) Power Rating (TAMB = 85ºC) 32-pin TQFN 5x5 mm 5433mW 43.47mW/ºC 3477mW 2825mW www.austriamicrosystems.com Revision 1.06 6 - 18 AS1112 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 8 Typical Operating Characteristics VDD = 5V, TAMB = 25ºC. Figure 3. Output Current vs. VDS; Figure 4. Output Current vs. VDS; 90 90 RIREF = 480Ω 80 80 70 70 60 60 50 IOUT (mA) . IOUT (mA) . RIREF = 480Ω RIREF = 1kΩ 40 30 20 50 RIREF = 1kΩ 40 30 20 RIREF = 3.9kΩ 10 RIREF = 3.9kΩ 10 0 0 0 3 6 9 12 15 0 0.5 1 VDS (V) 1.5 2 2.5 3 VDS (V) Figure 5. Output Current vs. REXT Figure 6. Output Current vs. Dot Correction Value 90 100 80 RIREF = 480Ω IOUT (mA) . IOUT (mA) . 70 10 60 50 40 30 RIREF = 1kΩ 20 10 1 0 0 1 2 3 4 5 6 7 8 9 10 0 REXT (kOhm) www.austriamicrosystems.com 9 18 27 36 45 54 63 Dot Correction Value Revision 1.06 7 - 18 AS1112 Datasheet - D e t a i l e d D e s c r i p t i o n 9 Detailed Description Serial Interface The AS1112 features a versatile 3-pin (CLK, SDI, and SDO) serial interface, which can be connected to microcontrollers or digital signal processors in various configurations. 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 AS1112 devices can be cascaded by connecting the SDO pin of one device with pin SDI of the next device (see Figure 15 on page 15). The SDO pin can also be connected to the microcontroller to receive status information from the AS1112. The serial data format is 96-bit or 192-bit wide, depending on mode of the device (see LD on page 2). Figure 7. Serial Data Input Timing Diagram Dot Correction Mode Data Input Cycle Greyscale Mode Data Input Cycle Dot Correction Mode Data Input Cycle MODE tH3 tSU3 tH3 LD SDI DCn-1 LSB DCn MSB DCn LSB tH2 CLK SDO 1 DCn-1 MSB DCn-1 MSB-1 96 DCn-1 LSB GSn MSB GSn LSB tSU2 tSU2 1 DCn MSB DCn-1 MSB-1 DCn+1 MSB 192 X X 1 SID MSB 2 X Error Information Output 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. 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 AS1112 devices can be ORed together and pulled up to VCC with a single pullup resistor (see Figure 15 on page 15). This reduces the number of signals needed to report a system error. 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 9). www.austriamicrosystems.com Revision 1.06 8 - 18 AS1112 Datasheet - D e t a i l e d D e s c r i p t i o n Table 9. XERR Truth Table Error Condition Temp. O p e n T e m p TJ < TTEF TJ > TTEF Thermal OUTn Voltage Error Flag Error Information Thermal LED Warning Open Detect Flag Selected Mode Short LED Detect Status OEN Mode XERR OUTn > VLOD 0 Don't Care 0 Don't Care 0 0 1 normal OUTn < VLOD 0 Don't Care 1 Don't Care 0 0 0 open error OUTn > VLOD 1 Don't Care 0 Don't Care 0 0 0 temp. error OUTn < VLOD 1 Don't Care 1 Don't Care 0 0 0 open & temp. error TJ > TTEF Don't Care 0 Don't Care Don't Care Don't Care 1 0 1 normal TJ < TTEF Don't Care 1 Don't Care Don't Care Don't Care 1 0 0 temp error TJ > TTWF Don't Care Don't Care 0 Don't Care Don't Care 1 1 1 normal TJ < TTWF Don't Care Don't Care 1 Don't Care Don't Care 1 1 0 temp. warn Overtemperature Error/Warning Flags The AS1112 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 AS1112 status register. To prevent an overtemperature condition the AS1112 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 AS1112 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 (see Table 9) and the voltage at OUTn is less than VLOD. Note: The voltage at each OUTn is sampled 1µs after being switched on. Please refer to Figure 8. 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 AS1112 status information data (SID) during a greyscale data input cycle. Shorted LED Detection The AS1112 integrated shorted LED detection circuit detects if any of the 16 LEDs is short-circuited. The shorted LED detection circuit trips when the error detection is activated and the voltage at OUTn is higher than VLSD. Note: The voltage at each OUTn is sampled 1µs after being switched on. Please refer to Figure 8. The shorted LED status of each channel can only be read out from the AS1112 status information data (SID) during a greyscale data input cycle. www.austriamicrosystems.com Revision 1.06 9 - 18 AS1112 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 8. Error Detection Timing (GS=FFFFHEX, DC=3FHEX) LD >1µs OEN GSCLK SID LODn, LSDn Error Detection Start LODn+1, LSDn+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. Delay Between Outputs The AS1112 uses graduated delay circuits between OUTn outputs. These circuits are contained in the constant-current driver block of the AS1112 (see Figure 1 on page 1). The average-delay time is 30ns (typ). The maximum delay is 450ns (typ) from OUT0 to OUT15. The delay scheme works by switching on and switching off each output channel. Thus the on/off time of each channel is the same regardless of the delay. These delays prevent large inrush currents and switching noise that can reduce bypass capacitance when the outputs are switched on. 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. Table 10. Pin OEN Truth Table OEN OUT0:OUT15 0 Normal Operation 1 Disabled Setting Maximum Channel Current 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 (1.24V 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: IMAX = VIREF x 31.5 (EQ 1) RIREF Where: VIREF = 1.24V; RIREF = User-selected external resistor. Figure 5 on page 7 shows the maximum output current IOUT versus RIREF, where RIREF is the value of the resistor between IREF terminal to GND, and IOUT is the constant output current of OUT0:OUT15. www.austriamicrosystems.com Revision 1.06 10 - 18 AS1112 Datasheet - D e t a i l e d D e s c r i p t i o n Power Dissipation To ensure proper operation of the device, the total power dissipation of the AS1112 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 DCn dPWM) 63 (EQ 2) Where: 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 The AS1112 operates in two modes (see Table 11). Greyscale operating mode (see Figure 12 on page 13) and the shift registers are in reset state at power-up. Table 11. Operating Modes Mode Input Shift Register Operating Mode 0 192-bit Greyscale PWM Mode 1 96-bit Dot Correction Data Input Mode Setting Dot Correction The AS1112 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: IOUTn = IMAX x DCn 63 (EQ 3) Where: 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 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 9). Channel data is put on one by one, and the data is clocked in with the MSB first. Figure 9. Dot Correction Data Packet Format MSB LSB 95 DC15.5 ... 90 89 DC15.0 DC14.5 DC OUT15 www.austriamicrosystems.com ... DC OUT14:DC OUT1 Revision 1.06 6 5 DC1.0 DC0.5 0 ... DC0.0 DC OUT0 11 - 18 AS1112 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 10. Dot Correction Data Input Timing Diagram Dot Correction Mode Data Input Cycle n Dot Correction Mode Data Input Cycle n +1 VCC MODE GND SDI DCn-1 LSB DCn MSB DCn MSB-1 tSU0 CLK DCn MSB-2 DCn LSB+1 DCn LSB DCn+1 MSB DCn+1 MSB-1 tWH0 1 2 1 95 96 1 2 tWL0 DCn-1 MSB SDO DCn-1 MSB-1 DCn-1 MSB-2 DCn-1 LSB+1 DCn-1 LSB DCn MSB-1 DCn MSB tWH2 tSU1 DCn MSB-2 tH1 LD 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: %Brightness = GSn x 100 4095 (EQ 4) 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. 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 11). Note: The data packet must be clocked in with the MSB first. Figure 11. Greyscale Data Packet Format LSB MSB 191 GS15.11 ... 180 179 GS15.0 GS14.11 GS OUT15 ... GS OUT14:GS OUT1 12 11 GS1.0 GS0.11 0 ... GS0.0 GS OUT0 When pin MODE is tied to GND, the AS1112 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 12). All greyscale data in the input shift register is replaced with status information data (SID) after latching into the greyscale register. www.austriamicrosystems.com Revision 1.06 12 - 18 AS1112 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 12. Greyscale Data Input Timing Diagram 1st Greyscale Mode Data Input Cycle After Dot Correction Input Dot Correction Mode Data Input Cycle Following Greyscale Mode Data Input Cycle MODE tH3 tSU3 LD tH3 GSn MSB DCn-1 LSB SDI GSn LSB tH2 tSU2 CLK SDO 1 DCn-1 MSB DCn-1 MSB-1 x GSn+1 LSB tSU1 tH0 96 GSn+1 MSB 192 x 1 SIDn MSB-1 SIDn MSB x 192 SIDn MSB-2 SIDn LSB SIDn MSB Status Information Data (SID) The AS1112 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 13). Open, shorted LED, temperature warning 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. Bit 174 contains the temperature warning flag. 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 13. Figure 13. Status Information Data Packet Format MSB LSB 191 LOD15 ... Open LED Detect Bit # 0:15 16:31 32:71 72:167 176 175 174 LOD0 TEF TWF ... 168 167 X DC15. Overtemperature ... 72 71 DC0. X ... 16:31 0:15 LOD LSD DC Values Description LED Short Detection, LSD LED Open Detection (Optional, same as bits 176:191), LOD Undefined Dot Correction Readback (16 x 6 Bit) Bit # Description 168:173 Undefined 174 Temperature Warning Flag (TWF, 125ºC, typ) 175 Temperature Error Flag (TEF, 150ºC, typ) 176:191 LED Open Detection, LOD 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 AS1112 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 14). www.austriamicrosystems.com Revision 1.06 13 - 18 AS1112 Datasheet - D e t a i l e d D e s c r i p t i o n Figure 14. Greyscale PWM Cycle Timing Diagram Greyscale PWM Cycle n+1 Greyscale PWM Cycle n OEN tWL1 tWH1 GSCLK tH4 tSU4 tWH3 2 1 3 4096 tW1 tPD1 tPD3 tPD3 OUT0 Current n x tD tPD3 tPD1 + tD OUT1 Current ... ... ... ... tPD1 + 15 x tD OUT15 Current tPD2 XERR www.austriamicrosystems.com Revision 1.06 14 - 18 AS1112 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 15 shows a cascaded arrangement AS1112 devices connected to a controller, building a basic module of an LED display system. Figure 15. Cascaded Configuration VCC VLED VLED VLED ... 100kΩ OUT0 VLED ... OUT15 OUT0 ... OUT15 SIN SDI SDO XERR SDI SDO VCC VCC XERR XERR CLK VCC VCC CLK LD LD GSCLK CLK 100nF AS1112 LD AS1112 100nF GSCLK TEST GSCLK TEST MODE GND MODE GND MODE OEN SOUT OEN OEN IREF IREF Controller 6 The maximum number of cascading AS1112 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 (EQ 5) Where: fGSCLK is the minimum frequency needed for GSCLK; fUPDATE is the update rate of whole cascaded system. fCLK = 193 x fUPDATE x n (EQ 6) Where: fCLK is the minimum frequency needed for CLK and SIN; fUPDATE is the update rate of whole cascaded system; n is the number of cascaded of AS1112 devices. www.austriamicrosystems.com Revision 1.06 15 - 18 AS1112 Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s 10 Package Drawings and Markings The device is available in an 32-pin TQFN 5x5 mm package. Figure 16. 32-pin TQFN 5x5 mm Package Symbol Min A 0.80 A1 b 0.18 D E D1 E1 3.50 3.50 Common Dimensions Nom Max Symbol 1.00 0.203 REF 0.23 5.00 BSC 5.00 BSC 3.60 3.60 3.70 3.70 Nom 0.5 BSC Max 0.30 0.40 0.50 e L 0.30 Min L1 0.10 P 45° BSC aaa 0.15 ccc 0.10 Notes: 1. Dimensioning and tolerancing conform to ASME Y14.5 M-194. 2. All dimensions are in millimeters while angle is in degrees. 3. Dimension b applies to metallized terminal and is measured between 0.25mm and 0.30mm from the terminal tip. Dimension L1 represents terminal full back from package edge up to 0.1mm is acceptable. 4. Coplanarity applies to the exposed heat slug as well as the terminal 5. Radius on terminal is optional. www.austriamicrosystems.com Revision 1.06 16 - 18 AS1112 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 12. Table 12. Ordering Information Model Description Delivery Form Package AS1112-BQFT 16-Channel LED Driver with Dot Correction and Greyscale PWM with Active-High TEST Input and Power-Down Mode Tape and Reel 32-pin TQFN 5x5 mm LED Driver with Dot Correction and Greyscale PWM AS1112B-BQFT 16-Channel with Active-Low XTEST Input and without Power-Down Mode Tape and Reel 32-pin TQFN 5x5 mm All devices are RoHS compliant and free of halogene substances. www.austriamicrosystems.com Revision 1.06 17 - 18 AS1112 Datasheet Copyrights Copyright © 1997-2009, austriamicrosystems AG, Schloss Premstaetten, 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. Disclaimer 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. 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. Contact Information Headquarters austriamicrosystems AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten - Graz, 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-us www.austriamicrosystems.com Revision 1.06 18 - 18