Atmel LED Drivers MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface Datasheet Brief Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface General Description The Atmel® LED DriversMSL4163 and MSL4164 compact, high-power LED string drivers use internal current control MOSFETs to sink up to 100mA per string, with current accuracy and matching better than 3%. The MSL4163/4 drive 16 parallel strings of 10 white LEDs each, for a total of 160 white LEDs per device. Sixteen interconnected devices control up to 2560 white LEDs. The MSL4164 features a 20MHz SPI bus, and the MSL4163 offers a 1MHz I2C serial interface. Both interfaces support video frame-by-frame LED string intensity control for up to 16 interconnected devices to allow active area dimming. The devices include an advanced PWM engine that easily synchronizes to a video signal, and per-string phase adjustment to reduce unwanted LCD artifacts such as motion blur. Additionally, an on-chip EEPROM allows the power-up defaults to be customized through the serial interface. The MSL4163/4 adaptively control the DC-DC converters that power the LED strings, using Atmel's Adaptive SourcePower™ technology. These efficiency optimizers minimize power use, while maintaining LED current accuracy. A unique combination of peak current controls and pulse width management offer simple, full- screen brightness control, versatile area dimming, and a consistent white point. One external resistor sets the global peak reference current for all LED strings, and global peak current fine-tuning is available through an 8-bit register. Global string drive pulse width is adjusted with an 8-bit global intensity register, and individual string pulse width is modulated with 12-bit registers. The MSL4163/4 feature fault monitoring of open circuit, short circuit, loss of video sync, and over-temperature conditions, and provide a fault output to notify the system controller. Detailed fault status and control are available through the serial interface. The MSL4163/4 are offered in 6 x 6 x 0.75mm, 40-pin TQFN packages and operate over a -40°C to 85°C temperature range. Applications Long Life, Efficient LED Backlighting for: • Televisions and Desktop Monitors • Medical and Industrial Instrumentation • Automotive Audio-visual Displays Channel Signs Architectural Lighting Ordering Information 16-CHANNEL LED STRING DRIVERS 2 PART INTERFACE PACKAGE MSL4163BT I2C 40-pin, 6 x 6 x 0.75mm TQFN MSL4164BT SPI 40-pin, 6 x 6 x 0.75mm TQFN Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface Key Features • 12-bit PWM String Dimming Operates at 240Hz • ±3% Current Accuracy and Current Balance • Fast Serial Interfaces Support up to 16 Devices per Bus: • Video Frame (Vsync) and Line (Hsync) Sync Inputs • Sync Loss Detectors Optionally Disable LED Strings - MSL4164: 20MHz SPI - MSL4163: 1MHz I2C • Multiple MSL4163/4s Share String Power Supplies and Automatically Negotiate the Optimum Supply Voltage • 8-bit Adaptive Power Correction Maximizes Efficiency of up to Three String Power Supplies • EEPROM Allows Customized Power-on Defaults • Drives 16 Parallel LED Strings of 10 White LEDs Each, for up to 2560 White LEDs per Serial Bus • Less than 1µa LED String-off Leakage Current • String Open Circuit and LED Short Circuit Detection with Adjustable Short Circuit Threshold • Supports Adaptive, Real-time Area Dimming for Highest Dynamic Range LCD TVs and Monitors • Individual Fault Detection Enable for Each String • Programmable String Phase Reduces Motion Blur • Over-temperature Shutoff Protection • Global Intensity Control via Serial Interface • -40°C To +85°C Operating Temperature Range • 100mA Peak, 60mA Average LED String Current • 4kv HBM ESD Rated String Drive Outputs • Single Resistor Sets Peak Current for all LED Strings Application Circuit VLED DC/DC PWM VOUT CONTROLLER (ANY NON-ISOLATED TOPOLOGY) FB 10 WHITE LEDs PER STRING COUT 1N4148 FBO1 5V STR0 VIN VDD 10µF 4.7µF MSL4163/4 ILED 12.7k STR15 16 STRINGS PER DEVICE W / RGB LED DRIVER GSC PHI GND SERIAL INTERFACE µC MSL4163/4 MSL4163/4 Atmel LED Drivers-MSL4163/MSL4164 SYNC SIGNALS FROM VIDEO SUBSYSTEM (OPTIONAL) 2 OR 4 WIRE UP TO 16 MSL3163/4s PER INTERFACE SENSORS 3 FBO2 FBI1 FBO1 NC VDD VIN EN ILED GND CGND Package Pin-out 40 39 38 37 36 35 34 33 32 31 FBI2 1 30 AD1 FBO3 2 29 SDA FBI3 3 28 TEST PHI 4 27 SCL GSC 5 26 AD0 PWM 6 MSL4163 STR0 7 (TOP VIEW) STR1 8 23 STR14 STR2 9 22 STR13 STR3 10 21 STR12 25 FLTB 11 12 13 14 15 16 17 18 19 20 STR4 STR5 STR6 STR7 CGND GND STR8 STR9 STR10 STR11 24 STR15 Figure 1. Atmel LED Driver-MSL4163 Pin-out, 40-pin TQFN. 4 Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 FBO2 FBI1 FBO1 NC VDD VIN EN ILED GND CSB 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface 40 39 38 37 36 35 34 33 32 31 FBI2 1 30 AD1 FBO3 2 29 MOSI FBI3 3 28 MISO PHI 4 27 SCK GSC 5 26 AD0 PWM 6 MSL4164 STR0 7 (TOP VIEW) STR1 8 23 STR14 STR2 9 22 STR13 STR3 10 21 STR12 25 FLTB 11 12 13 14 15 16 17 18 19 20 STR4 STR5 STR6 STR7 CGND GND STR8 STR9 STR10 STR11 24 STR15 Figure 2. Atmel LED Driver-MSL4164 Pin-out, 40-pin TQFN. Atmel LED Drivers-MSL4163/MSL4164 5 Figure 3. Package Dimensions: 40-pin, 6mm x 6mm x 0.75mm TQFN (0.5mm Pin Pitch) with Exposed Pad. 4.700 ±0.050 Exposed pad 6.000 ±0.050 PIN 1 DOT BY MARKING PIN #1 IDENTIFICATION CHAMFER 0.300 X 45° 0.400 ±0.050 6.000 ±0.050 40L TQFN (6x6mm) 0.0500 Bsc 4.700 ±0.050 Exposed pad 0.250 ±0.050 TOP VIEW 4.500 BOTTOM VIEW A MAX. NOM. MIN. TQFN 0.800 0.750 0.700 0.203 A 0.000 – 0.050 6 SIDE VIEW Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface Package Pin-out Table 1. Pin Descriptions PIN 1 PIN NAME PIN DESCRIPTION MSL4163 MSL4164 FBI2 FBI2 Efficiency Optimizer input 2 Connect FBI2 to FBO2 of the next device when chaining devices (Figure 7). If unused, connect FBI2 to GND. 2 FBO3 FBO3 Efficiency Optimizer output 3 Connect FBO3 to the third power supply’s feedback node or to FBI3 of the previous device when chaining devices (Figure 7). If unused, connect FBO3 to GND. 3 FBI3 FBI3 Efficiency Optimizer input 3 Connect FBI3 to FBO3 of the next device when chaining devices (Figure 7). If unused, connect FBI3 to GND. 4 PHI PHI Phase synchronization input Drive PHI with an external signal from 40Hz to 10kHz to synchronize the MSL4163/4 clock. PHI is typically the VSYNC signal input. 5 GSC GSC Gate shift clock input Drive GSC with the gate shift clock of the video signal from 0 to 10MHz. GSC is typically the HSYNC signal input. PWM input PWM allows direct external control of the brightness of all LED strings. The PWM input may also be used as a gate signal for the output of the PWM engine. Drive PWM with a pulse-width modulated signal with duty ratio ranging from 0% to 100% and frequency up to 5kHz. When not configured for use as an input, PWM is high impedance. 6 PWM PWM 7 - 14, 17 - 24 STR0 thru STR15 STR0 thru STR15 LED string current sink outputs Connect the cathode of the nth string’s bottom LEDs to STRn. Connect unused STRn outputs to GND. 15 CGND CGND Connect to ground Connect CGND to GND and to EP with short, wide traces. 16, 32 GND GND Signal ground Connect all GNDs to system ground and to EP with short, wide traces. 25 FLTB FLTB Fault indication output (active low) Open drain output FLTB sinks current to GND whenever a fault condition is verified. Toggle EN low or read the fault registers to clear FLTB. Once cleared, FLTB reasserts if the fault conditions persist. 26,30 AD0, AD1 AD0, AD1 27 28 SCL TEST SCK MISO Atmel LED Drivers-MSL4163/MSL4164 Slave ID selection inputs Connect AD1 and AD0 to GND through resistors to set the device address for the serial interface. MSL4163: I²C serial clock input SCL is the clock input for the I²C serial interface. MSL4164: SPI serial shift clock SCK is the clock input for the SPI bus. MSL4163: Factory test I/O Factory test. Make no electrical connection to TEST. MSL4164: Master input slave output MISO is the SPI serial data output. 7 Table 1. Pin Descriptions PIN 29 31 33 MSL4163 SDA GND ILED PIN DESCRIPTION MSL4164 MOSI CSB ILED MSL4163: I²C serial data I/O SDA is the data I/O for the I²C serial interface. MSL4164: Master input slave output MOSI is the SPI serial data input. MSL4163: Ground. Connect GND to system ground and to EP with short, wide traces. MSL4164: Chip select (active low) CSB is the chip select input for SPI transactions. CSB is active low. Maximum LED string current setting input Connect a resistor from ILED to GND to set the full-scale LED string current for all strings, using ISTRING = 762 / RILED. For example, connect a 12.7kΩ resistor to GND to set a 60mA maximum sink current through each LED string. 34 EN EN Enable input (active high) Drive EN high to turn on the MSL4163/4, and drive EN low to turn off the MSL4163/4. For automatic start-up, connect EN to VIN. When EN is low, the entire device, including the serial interface, is turned off. Driving EN high initiates a boot load of the EEPROM data into the control registers, simulating a cold start-up. 35 VIN VIN Supply voltage input Connect a 5V supply to VIN. Bypass VIN to GND with a 10µF ceramic capacitor placed close to VIN. 36 VDD VDD 2.5V internal LDO regulator output VDD powers internal logic. Bypass VDD to GND with a 4.7µF ceramic capacitor placed close to VDD. 37 NC NC 38 FBO1 FBO1 Efficiency Optimizer output 1 Connect FBO1 to the first power supply’s feedback node or to FBI1 of the previous device when chaining devices (Figure 7). If unused, connect FBO1 to GND. 39 FBI1 FBI1 Efficiency Optimizer input 1 Connect FBI1 to FBO1 of the next device when chaining devices (Figure 7). If unused, connect FBI1 to GND. FBO2 Efficiency Optimizer output 2 Connect FBO2 to the second power supply’s feedback node or to FBI2 of the previous device when chaining devices (Figure 7). If unused, connect FBO2 to GND. 40 EP 8 PIN NAME FBO2 EP EP No connection Leave NC unconnected. Exposed pad, power ground EP is the path that the string currents take to ground. EP also provides thermal relief for the die. Provide large traces from EP back to the string power supplies. Also connect EP to system ground and to GND using short, wide traces. Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface Absolute Maximum Ratings Voltage (With Respect to GND, CGND = EP = GND) VIN, EN......................................................................................................................................................................... -0.3V to +6V VDD.......................................................................................................................................................................... -0.3V to +2.75V MSL4163: SDA, SCL............................................................................................................................................. -0.3V to +6V MSL4164: MISO, MOSI, CSB, SCK............................................................................................ -0.3V to (VIN + 0.3V) FLTB............................................................................................................................................................................... -0.3V to +6V ILED, AD0, AD1..................................................................................................................................-0.3V to (VDD + 0.3V) PHI, GSC, PWM, FBO1, FBO2, FBO3, FBI1, FBI2, FBI3................................................. -0.3V to (VIN + 0.3V) STR0 thru STR15................................................................................................................................................ -0.3V to +40V CGND........................................................................................................................................................................ -0.3V to +0.3V Current (Into Pin) VIN................................................................................................................................................................................................ 50mA EP............................................................................................................................................................................................-1700mA STR0 thru STR15.............................................................................................................................................................. 105mA All other pins.............................................................................................................................................................................20mA Continuous Power Dissipation 40-pin 6mm x 6mm QFN (derate 37mW/°C above TA = +70°C)......................................................2963mW Ambient Operating Temperature Range TA = TMIN to TMAX....................................... -40°C to +85°C Junction Temperature ................................................................................................................ +125°C Storage Temperature Range...................................................................................... -65°C to +125°C Lead Soldering Temperature, 10s............................................................................................. +300°C Atmel LED Drivers-MSL4163/MSL4164 9 Electrical Characteristics Typical application circuit, VIN = 5V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VIN = 5V, TA = +25°C. PARAMETER SYMBOL CONDITIONS AND NOTES MIN TYP MAX UNIT 4.75 5 5.5 V 18 21 DC ELECTRICAL CHARACTERISTICS VIN operating supply voltage VIN operating supply current VIN IVIN EN = VIN, SLEEP = 0, RILED = 12.7kΩ, PHI = 240Hz, GSC = 983.04kHz, POWERCTRL = 0x4F, ISTR = 0xFF, OSCCTRL = 0x04, GSCINTEN = 0, PHIINTEN = 0, STRnEN = 1 PWMn = 0x7FF mA PWMn = 0xFFF 24 27.5 VIN shutdown supply current ISHDN EN = GND, SDA, SCL, AD0, AD1, PWM, PHI and GSC = GND 10 µA VIN sleep current ISLEEP EN = 1, SLEEP = 1, SDA, SCL, AD0, AD1, PWM, PHI and GSC = GND or VDD 1.5 mA VDD regulation voltage VDD 2.4 Input high voltage: SDA, SCL, PWM, PHI, GSC, MOSI, CSB, SCK VIH 0.7 x VDD Input low voltage: SDA, SCL, PWM, PHI, GSC, MOSI, CSB, SCK VIL 2.5 1.22 0.8 VOH ISOURCE = 5mA Output low voltage: PHI, GSC, SDA, MISO, FLTB VOL ISINK = 5mA ILED regulation voltage VIN – 0.4 FBI feedback input current 350 0 FBO feedback output current range VFBO ≤ VIN – 0.5V 0 FBO feedback output current step size FBI input disable threshold RILED = 12.7kΩ, ISTR = 0xFF, VSTRn = 1V STR0 thru STR15 sink current maximum RILED = 7.68kΩ, ISTR = 0xFF (Note 1) RILED = 12.7kΩ; ISTR = 0xFF, STR0 thru STR15 current load regulation FLDBKEN = 0, VSTRn = 1V to 5V STR0 thru STR15 current matching 10 55 RILED = 12.7kΩ, ISTR = 0x7F, VSTRn = 1V VSTR RILED = 12.7kΩ; ISTR = 0xFF 60 V mV 365 μA 365 μA 1.1 STR0 thru STR15 sink current V V 0.4 RILED = 12.7kΩ V V Input low voltage: EN Output high voltage: PHI, GSC, MISO V V 0.3 x VDD Input high voltage: EN STR0 thru STR15 minimum headroom 2.6 μA 140 mV 67 mA 100 mA 0.033 %/V -5 5 0.5 % V Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface PARAMETER STR0 thru STR15 short circuit fault detection threshold SYMBOL SCREF STR0 thru STR15 current slew rate Thermal shutdown temperature PARAMETER CONDITIONS AND NOTES MIN TYP SCTHR = 0x00 4.5 SCTHR = 0x01 5.0 SCTHR = 0x02 5.5 SCTHR = 0x03 6.0 Current rising (Note 2) 608 Current falling (Note 2) 10868 (Note 2) SYMBOL CONDITIONS AND NOTES MAX UNIT V mA/µs 135 °C MIN TYP MAX UNIT 18.15 20.00 21.88 MHz 10 kHz AC ELECTRICAL CHARACTERISTICS OSC frequency fOSC PHI frequency fPHI OSCCTRL = 0x04 0.04 PHI lock PHI cycles 4 GSC frequency fGSC PWM frequency fPWM 0 PWM duty cycle PARAMETER 10 MHz 50 kHz 100 % MAX UNIT 1 MHz 0 SYMBOL CONDITIONS AND NOTES MIN TYP I²C TIMING CHARACTERISTICS, MSL4163 SCL clock frequency Bus timeout period STOP to START condition bus free time 1/tSCL ttimeout Bus timeout disabled (Note 3) 0 OSCCTRL = 0x04 fOSC = 16MHz to 23MHz 30 ms 600,000 / fOSC s tBUF 0.5 µs tHD:STA 0.26 µs Repeated START condition setup time tSU:STA 0.26 µs STOP condition set-up time tSU:STOP 0.26 µs SDA data hold time tHD:DAT 0 ns SDA data valid acknowledge time tVD:ACK (Note 4) 0.05 0.45 µs SDA data valid time tVD:DAT (Note 5) 0.05 0.45 µs SDA data set-up time tSU:DAT 100 ns SCL clock low period tLOW 0.5 µs SCL clock high period tHIGH 0.26 µs Repeated START condition hold time SDA, SCL fall time tf SDA, SCL rise time tr SDA, SCL input suppression filter period tSP Atmel LED Drivers-MSL4163/MSL4164 (Note 6) (Note 7) (Note 8) 50 120 ns 120 ns ns 11 PARAMETER SYMBOL CONDITIONS AND NOTES MIN TYP MAX UNIT 20 MHz SPI TIMING CHARACTERISTICS, MSL4164 SCK frequency CSB to rising edge of SCK set-up time tCSB:SCK(SU) 20 ns Rising edge of SCK to CSB hold time tCSB:SCK(HD) 20 ns MOSI to rising edge of SCK set-up time tMOSI(SU) 20 ns Rising edge of SCK to MOSI hold time tMOSI(HD) 20 ns MOSI, CSB, SCK signal rise time tR(SPI) receiving 5.0 ns MOSI, CSB, SCK signal fall time tF(SPI) receiving 5.0 ns MISO signal rise time MISO signal fall time Cload = 10pF 20 ns Cload = 10pF 20 ns CSB falling edge to MISO data valid tCSB:MISO(DV) 50 ns CSB rising edge to MISO high impedance tCSB:MISO(HIZ) 50 ns tVALID 20 ns SCK falling edge to MISO data valid Note 1. Subject to thermal dissipation characteristics of the device Note 2. Guaranteed by design, and not production tested. Note 3. Minimum SCL clock frequency is limited by the bus timeout feature, which resets the serial bus interface if either SDA or SCL is held low for ttimeout. Disable bus timeout via the power control register 0x02[6]. Note 4. tVD:ACK = SCL low to SDA (out) low acknowledge time. Note 5. tVD:DAT = minimum SDA output data-valid time following SCL low transition. Note 6. A master device must internally provide an SDA hold time of at least 300ns to ensure an SCL low state. Note 7. The maximum SDA and SCL rise times are 300ns. The maximum SDA fall time is 250ns. This allows series protection resistors to be connected between SDA and SCL inputs and the SDA/SCL bus lines without exceeding the maximum allowable rise time. Note 8. MSL4163/4 include input filters on SDA, SCL, AD0, and AD1 inputs that suppress noise less than 50ns. 12 Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface Block Diagram The block diagram for the MSL4163/4 is shown in Figure 4. Figure 4. Atmel LED Drivers-MSL4163/4 Block Diagram. VIN EN FBI1 FBO1 FBI2 FBO2 FBI3 FBO3 LDO REGULATOR STRING CURRENT CONTROL VDD = 2.5V VDD ILED STRING FBO SELECT AND FAULT DETECTION EFFICIENCY OPTIMIZER LOGIC AND CONTROL + - REF SDA (MOSI) SCL (SCK) (MISO) (CSB) AD1 AD0 I2C - MSL3163 (SPI - MSL3164) INTERFACE FLTB FAULT STATUS STR0 + - 8-BIT ISTR DAC STR15 + - E2PROM + - SYSTEM CONTROLLER PWM GSC PHI STRING DUTY, PHASE AND FADE CONTROL PWM SIGNALS MSL4163 MSL4164 DGND Atmel LED Drivers-MSL4163/MSL4164 AGND EP 13 MSL4164 EP 30 29 28 27 26 25 24 23 22 21 AD1 MOSI MISO SCK AD0 FLTB STR15 STR14 STR13 STR12 STR11 STR10 STR9 STR8 AGND DGND STR7 STR6 STR5 STR4 20 19 18 17 16 15 14 13 12 11 CSB FLTB SCK MISO MOSI VSYNC HSYNC PWM - + +5V ENABLE 1 2 3 4 5 6 7 8 9 10 4.7µF 10µF 1N4148 CSB AGND ILED EN VIN VDD NC FBO1 FBI1 FBO2 FBI2 FBO3 FBI3 PHI GSC PWM STR0 STR1 STR2 STR3 12.7kΩ RILED RTOP RBOTTOM 31 32 33 34 35 36 37 38 39 40 FB VOUT LED STRING DC/DC CONVERTER COUT 10k Ω 10kΩ Typical Application Circuit Figure 5. Atmel LED Driverr-MSL4164 Driving 160 White LEDs in 16 Strings at 60mA per String. 14 Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface Detailed Description The MSL4163 and MSL4164 are highly integrated, flexible multi-string LED drivers with power supply control to maximize system efficiency. The drivers easily connect to a video subsystem. Although optional, this offers a simple architecture for use in LCD TV backlight applications. Up to 16 drivers easily connect together to drive large numbers of LED strings in a system. The drivers provide multiple methods of controlling LED brightness through both peak current control and pulse width control of the string drive signals. Peak current control offers excellent color consistency, while pulse width control allows brightness management. An onchip EEPROM holds all the default control register values. At power-up, the data in the EEPROM are automatically copied directly to the control registers, setting up the device for operation. The devices interface to an MCU via I2C (MSL4163) or SPI (MSL4164). The robust, 1MHz I2C interface supports up to 16 devices on the bus. The 20MHz bus addressable SPI bus supports up to 16 devices per chip select line. While typically the LED drive PWM signal is internally generated, both drivers also accept an external, direct-drive PWM signal and offer optional string drive phase spreading. With direct-drive PWM, a pulse width modulated signal applied to the PWM input sets the PWM duty cycle and the frequency of the LED drive signal. With phase spreading enabled, a progressive 1/16 PWM-frame time delay per string helps reduce both the transient load on the LED power supplies and the power supply input capacitor size requirements. The PWM frequency of the drivers is either synchronized to an external signal applied to PHI or generated from the internal oscillator for standalone applications. Typically, the VSYNC signal from the video system is used for the PHI input. The on time of each string is individually programmed via the device registers, providing a peak resolution of 12 bits when using the on-chip PWM generator. The actual resolution of the PWM frequency depends on the ratio of the Atmel LED Drivers-MSL4163/MSL4164 GSC frequency (typically provided by a system’s HSYNC signal, but can be internally generated) to the PHI frequency, because the on time of a string is programmed as a 12-bit count of the number of GSC clock cycles. This count can be further scaled by an 8-bit global intensity value, when enabled. The GSC clock is also used to precisely set each string’s phase delay so that it is synchronized relative to the video frame. The efficiency optimizers control a wide range of external DC-DC and AC-DC converter architectures. Multiple drivers in a system communicate with each other in real time to select an optimized operating voltage for the LEDs. This allows design of the power supply for the worst case forward voltage (Vf) of the LEDs without concern about excessive power dissipation issues. During the start-up sequence, the MSL4163/4 automatically reduce the power supply voltage to the minimum voltage required to keep the LEDs in current regulation. The devices can be configured to periodically perform this optimization to compensate for changes in the LED forward voltage, and to assure continued optimum power savings. Internal Regulators and Enable Input The MSL4163/4 includes an internal linear regulator that operates from the 5V nominal input supply, VIN, and provides an internal 2.5V supply, VDD, to power the low-voltage internal circuitry. Bypass VDD (pin 36) to GND with a 4.7μF capacitor. Bypass VIN (pin 35) to GND with a 10µF capacitor. The MSL4163/4 enable input, EN, enables the device. Drive EN low to enter low power operation, which lowers quiescent current draw to less than 20µA. With EN low, the serial interface is ignored. Drive EN high to turn on the device. When EN is driven high, the contents of the EEPROM are boot loaded into the control registers, simulating a cold start-up. 15 Setting the LED String Current with RILED and ISTR The MSL4163/4 features 16 current sink outputs rated at 40V, each designed to sink up to 100mA peak. Limit average current to 60mA if the PCB copper around the MSL4163/4 is the only heat sink employed. The maximum string current, IILED, for all 16 LED string inputs is set by a single external resistor, RILED, placed from ILED to GND, whose value is determined using: RILED = 762 . I ILED For example, a full-scale LED current of 60mA returns RILED = 12.7kΩ. The current for all LED strings is reduced from its full-scale value with 8-bit resolution using ISTR, the string current control register, 0x0F. VOUT POWER SUPPLY RTOP FB COUT 1N4148 RBOTTOM FBOn STR0 STR15 MSL4163 MSL4164 Figure 6. FBOn Connects to the Power Supply Voltage Divider through a Diode. Connecting the Efficiency Optimizer to an LED String Power Supply and Selecting Resistors The MSL4163/4 are designed to control LED string power supplies that use a voltage divider (RTOP and RBOTTOM in Figure 6) to set output voltage, and whose regulation feedback voltage is not more than 3.5V. The efficiency optimizer improves power efficiency by injecting a current of between 0 and 255µA into the voltage divider of the external power supply, dynamically adjusting the power supply’s output to the minimum voltage required by the LED strings. To select the resistors, first determine VOUT(MIN) and VOUT(MAX), the minimum and maximum string supply voltage limits, using: VOUT ( MIN) = (Vf ( MIN) ∗ [# ofLEDs])+ 0.5 , and VOUT ( MAX) = (Vf ( MAX) ∗ [# ofLEDs])+ 0.5 , 16 Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface where Vf(MIN) and Vf(MAX) are the LEDs’ minimum and maximum forward voltage drops at the peak current set by RILED (page 10). For example, if the LED data are Vf(MIN) = 3.5V and Vf(MAX) = 3.8V, and 10 LEDs are used in a string, then the total minimum and maximum voltage drops across the LEDs are 35V and 38V, respectively. Adding an allowance of 0.5V to the string drive MOSFET headroom brings VOUT(MIN) to 35.5V and VOUT(MAX) to 38.5V. Do not to exceed the 40V maximum specification of string drivers STR1 - STR15. Then, determine RTOP using: RTOP = VOUT ( MAX ) − VOUT ( MIN ) I FBOn ( MAX ) , where IFBOn(MAX) is the 255µA maximum output current of the efficiency optimizer outputs, FBOn (if cascading multiple MSL4163/4s determine IFBOn(MAX) as shown in the next section). Finally, determine RBOTTOM using: RBOTTOM = RTOP * VFB VOUT(MAX) _ VFB , where VFB is the regulation feedback voltage of the power supply. Place a diode (1N4148 or similar) between FBOn and the supply’s feedback node to protect the MSL4163/4 against current flow into FBOn. Using Multiple Atmel LED Drivers-MSL4163/4s to Control a Common Power Supply Cascade multiple MSL4163/4 devices into a chain configuration, with the FBIn of one device connected to the FBOn of the next (Figure 7). Connect the first FBOn to the power supply feedback resistor node through a diode and the unused FBIn inputs (and any unused FBOn outputs) to GND as close to the MSL4163/4 as possible. Assign all strings powered by a common supply to the proper FBOn output using string set registers (STRnSET) 0x20 - 0x3F. The chained devices work together to ensure that the system operates at optimum efficiency. Note that the accuracy of the feedback chain may degrade through each link of the FBIn/FBOn chain by as much as 2%. Determine the potential worst case maximum FBOn current IFBOn(MAX/MIN) using: IFBOn (MAX / MIN) = 225 A* (0.98)N-1 , where N is the number of MSL4163/4s connected in series. Use this result in the above RTOP resistor equation for the term IFBOn(MAX) instead of using 255µA. Take care in laying out the traces for the efficiency optimizer connections. Minimize the FBIn/FBOn trace lengths as much as possible. Do not route the signals close to traces with large variations in voltage or current, because noise may couple into FBIn. If these traces must be routed near noisy signals, shield them from noise by using ground planes or guard traces. Atmel LED Drivers-MSL4163/MSL4164 17 VOUT POWER SUPPLY 1 RTOP FB RBOTTOM 1N4148 VOUT POWER SUPPLY 2 RTOP FB STRn RBOTTOM 1N4148 FBO1 FBO2 FBO3 STRm FBI1 FBI2 FBI3 STRn STRm FBO1 FBO2 FBO3 FBI1 FBI2 FBI3 STRn FBO1 FBO2 FBO3 STRm FBI1 FBI2 FBI3 DEVICE 1 DEVICE 2 DEVICE N MSL4163 MSL4164 MSL4163 MSL4164 MSL4163 MSL4164 Figure 7. Example of Cascading Multiple Devices to Optimize Common Power Supplies. Direct PWM Control of the LED Strings An external PWM signal applied to the PWM input allows direct PWM control over the strings when bits PWMEN and PWMDIRECT are set in PWM control register, 0x1E. This configuration bypasses PHI and GSC, but allows automatic LED string phase delay using bit D2 of register 0x1E. The PWM input can also be configured as a gate for the output of the PWM engine using the PWM global enable bit D3 of the PWM control register, 0x1E. 18 Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface Register Map and the EEPROM Register Map Summary The MSL4163/4 controlled using the 96 registers in the range 0x00 - 0x5F (Table 2). It may be convenient, and it is allowed, to read and write to unused bits in this range when accessing registers, but always write zeros. Reads from unused bits always return zeros. Three additional registers, 0x90, 0x91, and 0x93, allow access to the EEPROM and provide efficiency optimizer status. The power-up default values for all control registers are stored within the on-chip EEPROM, and any of these EEPROM values may be changed through the serial interface. Table 2. Atmel LED Drivers-MSL4163/4 Register Map ADDRESS AND REGISTER NAME 0x00 CONTROL0 0x01 CONTROL1 FUNCTION LED string enables 0x02 POWERCTRL Fault configuration 0x03 FLTSTATUS Fault status, global 0x04 OCSTAT0 0x05 OCSTAT1 0x06 SCSTAT0 0x07 SCSTAT1 0x08 FLTMASK0 0x09 FLTMASK1 0x0A FBOCTRL0 0x0B FBOCTRL1 0x0C FBODAC1 0x0D FBODAC2 0x0E FBODAC3 String open circuit fault status REGISTER DATA D7 D6 D5 D4 D3 STR6EN STR5EN STR4EN STR3EN STR2EN STR1EN STR0EN STR14EN STR13EN STR12EN STR11EN STR10EN STR9EN STR8EN SLEEP I2CTOEN PHIMINFEN GSCMAXFEN STRSCFEN STROCFEN FBOOCEN FBOEN - - PHIMINFLT GSCMAXFLT STRSCDET STROCDET FBOOC FLTDET OC7 OC6 OC5 OC4 OC3 OC2 OC1 OC0 OC15 OC14 OC13 OC12 OC11 OC10 OC9 OC8 String short circuit fault status SC7 SC6 SC5 SC4 SC3 SC2 SC1 SC0 SC15 SC14 SC13 SC12 SC11 SC10 SC9 SC8 String fault masks FLTEN7 FLTEN6 FLTEN5 FLTEN4 FLTEN3 FLTEN2 FLTEN1 FLTEN0 FLTEN15 FLTEN14 FLTEN13 FLTEN12 FLTEN11 FLTEN10 FLTEN9 FLTEN8 Efficiency optimizer control HDRMSTEP[1:0] FBCLDLY[1:0] FBSDLY[1:0] SCCDLY[1:0] DECRSTEP[1:0] INITPWM ACALEN ICHKDIS FBODAC3[7:0] OSCCTRL Oscillator frequency - - - - - 0x11 GSCCTRL GSC processing control GSCCHKSEL - - - GSCMAXEN GSCGEN Internal GSC clock generator 0x14 GSCMUL GSC multiplier - - - 0x15 GSCDIV GSC divider - - - GSCMAX Max oscillator cycles between GSC pulses Atmel LED Drivers-MSL4163/MSL4164 ACAL100 FBODAC2[7:0] 0x10 0x17 FBCFDLY[1:0] FBODAC1[7:0] Efficiency optimizer DAC readback ISTR 0x16 D0 STR7EN 0x0F 0x13 D1 STR15EN 8-bit global string current 0x12 D2 ISTR[7:0] OSCTRL[2:0] GSCPOL GSCPHISYNCEN GSCINTEN GSCGEN[7:0] GSCGEN[15:8] GSCMUL[4:0] - GSCDIV[3:0] GSCMAX[7:0] GSCMAX[15:8] 19 Table 2. Atmel LED Drivers-MSL4163/4 Register Map ADDRESS AND REGISTER NAME 0x18 0x19 0x1A 0x1B 0x1C FUNCTION PHICTRL PHI processing control PHIGEN Internal PHI clock generator REGISTER DATA D7 D6 D5 - - - D4 D3 - - - - 0x1E PWMCTRL PWM control FLDBKEN - GINTEN PWMOFLOWEN 0x1F GINT Global PWM scaling STR0SET Phase delay and EO assignment for string 0 ↓ ↓ ↓ Phase delay and EO assignment for string 15 PHDLY15[7:0] STR15SET PWM0 12-bit PWM setting for string 0 0x20 0x3E 0x40 0x41 ↓ 0x5E 0x5F PHIPOL PHIINTEN UNUSED - 0x3F PHIMINEN UNUSED - ↓ D0 PHIGEN[15:8] PHIMIN 0x21 D1 PHIGEN[7:0] Min GSC pulses over PHI period 0x1D D2 PHIMIN[7:0] PHIMIN[11:8] PWMGLBLEN PHADLYEN PWMDIRECT PWMEN GINT[7:0] PHDLY0[7:0] COLSTR0[1:0] COLSTR15[1:0] - - - PHDLY[11:8] - PHDLY[11:8] PWM0[7:0] - - - - PWM0[11:8] ↓ ↓ ↓ PWM15 12-bit PWM setting for string 15 PWM15[7:0] SCTHRESH Short circuit threshold - - - - PWM15[11:8] - DO NOT ACCESS ADDRESS RANGE 0X60 THRU 0X73 0x74 - - - - - - SCTHR[0:1] - DO NOT ACCESS ADDRESS RANGE 0X75 THRU 0X8F 0x90 E2ADDR 0x91 E2CTRLSTA EEPROM read/write access 0x93 FBOSTATUS FBO status 20 E2BUSY E2ADDR[6:0] BLDACT FBOOPEN[3:1] E2ERR - FBOACTIVE[3:1] RWCTRL[2:0] FBOCAL FBOINITCAL Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface Register Power-Up Defaults Register power-up default values are shown in Table 3. Table 3. Atmel LED Drivers-MSL4163/4 Register Power-up Defaults REGISTER NAME AND ADDRESS POWER-UP CONDITION REGISTER DATA D7 D6 D5 D4 D3 D2 D1 D0 0x00 CONTROL0 LED strings STR0 thru STR7 enabled 1 1 1 1 1 1 1 1 0x01 CONTROL1 LED Strings STR8 thru STR15 Enabled 1 1 1 1 1 1 1 1 0x02 POWERCTRL Efficiency optimizer outputs enabled FBO open circuit detection enabled String open circuit detection enabled LED short circuit detection enabled GSC maximum fault detection disabled PHI minimum fault detection disabled I2C bus timeout detection enabled Device awake 0 1 0 0 1 1 1 1 0x08 FLTMASK0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 Strings current set to 50% of RILED setting 0 1 1 1 1 1 1 1 Fault detection enabled on all strings 0x09 FLTMASK1 0x0A FBOCTRL0 0x0B FBOCTRL1 0x0F ISTR 0x10 OSCCTRL fOSC = 20MHz 0 0 0 0 0 1 0 0 0x11 GSCCTRL GSC synchronized to the falling edge of the external signal 0 0 0 0 0 0 0 0 Although disabled, internal GSC frequency = 20MHz / (19 + 1) = 1MHz 0 0 0 1 0 0 1 1 GSCGEN 0 0 0 0 0 0 0 0 0x12 0x13 Current sink error confirmation delay = 4µS FBO power supply correction delay = 2ms Efficiency optimizer recalibration delay = 1s Efficiency optimizer correction steps = 6 Current sink error detection not disabled auto recalibration enabled PWM settings used during auto recalibration PWM duty cycle = 100% during initial calibration Efficiency optimizer operates using 1µA steps LED short circuit confirmation delay = 4µs Atmel LED Drivers-MSL4163/MSL4164 21 Table 3. Atmel LED Drivers-MSL4163/4 Register Power-up Defaults REGISTER NAME AND ADDRESS POWER-UP CONDITION REGISTER DATA D7 D6 D5 D4 D3 D2 D1 D0 0x14 GSCMUL GSC multiplied by 4 0 0 0 0 0 0 1 1 0x15 GSCDIV GSC not divided 0 0 0 0 0 0 0 0 Although disabled, GSC max count is set to 19 clock cycles 0 0 0 1 0 0 1 1 GSCMAX 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 1 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PWM operation enabled Internal PWM engine determines tON and tOFF Phase delay enabled PWM input not used as gate for PWM engine output String on times allowed to extend beyond PWM frame GINT ignored String current foldback enabled 1 0 0 1 0 1 0 1 Although disabled, global intensity is set to (127) / 256 = 49.6% 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0* 1* 0 0 0 0 0 0 0x16 0x17 0x18 PHICTRL PHI synchronized to the falling edge of the external signal PHIGEN Although disabled, internal PHI frequency = 20MHz / (8 * (10416 + 1)) = 240Hz 0x19 0x1A 0x1C PHIMIN No PHI minimum 0x1D 0x1E PWMCTRL 0x1F GINT 0x20 STR0SET 0x21 ↓ ↓ 0x3E All strings set to zero phase delay Strings efficiency optimizer assignments are: FBO1: Strings 0,4,8,12 FBO2: Strings 1,2,5,6,9,10,13,14 FBO3: Strings 3, 7, 11, 15 ↓ 0 0 0 0 0 0 0 0 1* 1* 0 0 0 0 0 0 STR15SET 0x3F 22 Atmel LED Drivers-MSL4163/MSL4164 Atmel LED Drivers-MSL4163/MSL4164 16-string, White and RGB LED Drivers with Adaptive Power Control, EEPROM, and SPI/I²C/SMBus Serial Interface REGISTER NAME AND ADDRESS POWER-UP CONDITION 0x40 REGISTER DATA D7 D6 D5 D4 D3 D2 D1 D0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 PWM0 0x41 ↓ ↓ All strings have PWM value = 512 GSC cycles 0x5E ↓ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 SCREF = 6.0V 0 0 0 0 0 0 1 1 EEPROM 7-bit address = 0x00 0 0 0 0 0 0 0 0 PWM15 0x5F 0x74 SCTHRESH 0x90 E2ADDR 0x91 E2CTRLSTA EEPROM read/write disabled 0 0 0 0 0 0 0 0 0x93 FBOSTATUS Feedback output status 0 0 0 0 0 0 0 0 * These bits set the FBOn string assignments. Atmel LED Drivers-MSL4163/MSL4164 23 Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131 USA Tel: (+1)(408) 441-0311 Fax:(+1)(408) 487-2600 www.atmel.com Atmel Asia Limited Unit 01-5 & 16, 19F BEA Tower, Millennium City 5 418 Kwun Tong Road Kwun Tong, Kowloon HONG KONG Tel: (+852) 2245-6100 Fax:(+852) 2722-1369 Atmel Munich GmbH Business Campus Parkring 4 D-85748 Garching b. Munich GERMANY Tel: (+49) 89-31970-0 Fax:(+49) 89-3194621 Atmel Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 JAPAN Tel: (+81)(3) 3523-3551 Fax:(+81)(3) 3523-7581 © 2011 Atmel Corporation. All rights reserved. / Rev.: MEM-MSL4163/64DB1-E-US_06-11 Atmel®, logo and combinations thereof, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and products descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life.