Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface Datasheet Brief Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface General Description Atmel LED Driver-MSL3162 is a compact, high-power, 16-parallel-string LED driver. It uses internal current control MOSFETs to sink up to 100mA per LED string with better than 3% accuracy and with up to 10 series white LEDs per string, or 160 LEDs per MSL3162. The advanced PWM engine is easily synchronized to the video signal and refresh timing using a built-in DLL multiplier and sync dividers. Per-string phase adjustment reduces unwanted LCD artifacts such as motion blur. Up to 16 MSL3162s can share the same 1MHz I2C/SMBus-compatible serial interface, which is fast enough for frame-by-frame LED string intensity control of 16 MSL3162s, or 2560 white LEDs in total. The MSL3162 adaptively controls the voltage powering the LED strings using patented Atmel's Efficiency Optimizer control. The Efficiency Optimizer minimizes LED driver power losses while maintaining high current accuracy. The MSL3162 uses 6-bit analog (LED current) dimming as well as 10-bit PWM dimming control. PWM dimming is derived from the product of the 8-bit individual string PWM setting, the 6-bit global intensity, and the 8-bit thermal derating. One external resistor provides the global reference current for all the LED strings. The MSL3162 features fault monitoring of open circuit, short circuit, and overtemperature conditions, with fault status available through the dedicated FLTB output as well as the I2C/SMBus serial interface. It supports both individual device I2C read/write and broadcast write commands, allowing multiple MSL3162s to be configured simultaneously. The MSL3162 includes on-chip user EEPROM, allowing customization of the internal register power-up defaults. The MSL3162 is offered in a lead-free, halogen-free, RoHS-compliant package with 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 Digital Signage Solid-State Lighting Ordering Information 2 PART DESCRIPTION PACKAGE MSL3162BT 16-ch LED driver 40-pin, 6x6x0.75mm TQFN Atmel LED Driver-MSL3162 Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface Key Features • 100ma Maximum Peak LED String Current • Adaptive Power Correction Optimizes LED Supplies • Multiple MSL3162s Can Share String Supplies • MSL3162s Automatically Negotiate The Lowest Supply Voltage That Maintains Regulation Across All MSL3162s • Better Than ±3% Current Accuracy and Balance • Single Resistor Sets Peak Current For All LED Strings • Individual LED String Intensity (Peak Current And PWM) • Individual LED String Phase Controls • Global LED Intensity Control – I2C Or PWM Input Pin • Programmable String Phase Delays Reduce Motion Blur • Flexible Video Frame (VSYNC) And Line (HSYNC) Synchronization With DLL Multiplier and Dividers • Sync Loss Detectors Optionally Disable LED Strings • Open Circuit and Short Circuit Fault Detection • Individual Fault Detection Enables For Each String • 1Mhz I2C/SMbus Interface with 16 Slave Addresses • I2C/SMbus Broadcast Mode Simplifies Configuration • User EEPROM Saves Power-On Default Settings • Die Over-Temperature Cutoff Protection • <1µa LED String Current Sink Off Leakage Current • Automatic LED Current Temperature Compensation • -40°C To +85°C Operating Temperature Range • Lead-Free, Halogen-Free, RoHs-Compliant Package • Supports Adaptive, Real-Time 2D Area Dimming For Highest Dynamic Range LCD TVs and Monitors Application Circuit Atmel LED Driver-MSL3162 3 Quick Start Guide The MSL3162 is an LED string driver that drives, monitors, and dims up to 160 white LEDs (up to 10 series and up to 16 parallel) at high efficiency for LCD backlighting and signage applications. This section summarizes the capabilities of the MSL3162 for quick evaluation. How Many LEDS and Drivers? The MSL3162 drives 16 strings of series-connected LEDs. The maximum number of LEDs per string is limited to 10 white LEDs by the 40V maximum string voltage rating. More series LEDs can be driven if their forward voltage (VF) is lower. When an LED string is turned off, the voltage across the LEDs does not drop to zero. This allows more series LEDs to be driven, but eliminates the MSL3162's ability to sustain a shorted LED string. Sixteen MSL3162s can share an I2C/SMBus serial interface, with both individual and broadcast (all MSL3162s on a bus) addressing. The high total LED drive capability of multiple bussed MSL3162s makes the driver suitable for LCD TV and monitor backlights as well as LED signage and general lighting. The LED drive capability is summarized in Table 1. Table 1. Atmel LED Driver MSL3162 LED Drive Capability LED TYPE VF(MAX) LEDs IN STRING PER MSL3162 16 X MSL3162s LED POWER PER MSL3162 LED POWER 16 X MSL3162s White, Green, Blue 3.6V 10 LEDs 160 LEDs 2560 LEDs Red 2.4V 15 LEDs 240 LEDs 3840 LEDs 34W (at 60mA string current) 544W (at 60mA string current) RGB - 10 LEDs 50 RGB LEDs 800 RGB LEDs 26W (at 60mA) 415W (at 60mA) LEDS, Power Supplies (PSUs), and Efficiency Optimizers The MSL3162 obtains high efficiency by adjusting up to three LED string power supplies to deliver the minimum necessary voltage to accurately drive all LED strings connected to each LED string supply via the three Efficiency Optimizers. Multiple MSL3162s sharing string supplies automatically negotiate the voltage among themselves using the FBI/FBO pins. No system intervention is needed after initial configuration. Use any appropriate LED string power supply topology, typically a DC-DC boost or buck converter with a controllable resistive feedback voltage divider. The Efficiency Optimizer sets the LED voltage to maintain regulation on the highest voltage LED string. The better the LED string voltage matching, the lower the dissipation the MSL3162 absorbs, and, therefore, better LED matching improves efficiency. RGB LEDs should be driven by three separate string supplies. Also, consider using multiple string supplies for high-power, single-color systems, such as a white backlight. 4 Atmel LED Driver-MSL3162 Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface Timing, PWM, Intensity Controls and Synchronization The internal PWM dimming is synchronized to the LCD's frame timing through the PHI input (typically VSYNC) and the GSC input (typically HSYNC) to eliminate beating artifacts and maintain high timing accuracy. Suitability for LED backlight architectures is shown in Table 2. LED area dimming for direct backlighting is supported for contrast improvement. Motion blur is reduced by setting each LED string's PWM phasing individually to synchronize PWM off times with the LCD refresh timing for the zone being lit. Table 2. Atmel LED Driver-MSL3162 LED Common Backlight Drive Architectures STRING SUPPLY OPTIONS MOTION BLUR REMOVAL LED ZONE MANAGEMENT White LED – Bottom, edge-lit No No White LED – Top/bottom, edge-lit No No No No Yes - LED strip phasing Higher contrast ratio (area dimming) Yes - LED strip phasing Higher contrast ratio and color gamut BACKLIGHT TYPE White LED – Four sides, edge-lit Up to three efficiency optimized supplies White LED – Direct, back-lit RGB LED – Direct, back-lit Atmel LED Driver-MSL3162 R, G, B efficiency optimized supplies 5 FBO2 FBI2 FBO1 FBI1 VDD VIN EN ILED N/C GND Package Pin-out 40 39 38 37 36 35 34 33 32 31 FBI3 1 30 N/C FBO3 2 29 AD0 CGND 3 28 SDA PHI 4 27 SCL GSC 5 26 AD1 PWM 6 MSL3162-TB 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 GND CGND STR8 STR9 STR10 STR11 24 STR15 Figure 1. 40-pin, 6mm x 6mm x 0.75mm TQFN (0.5mm pin pitch) with Exposed Pad 6 Atmel LED Driver-MSL3162 Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface Package Pin-out Figure 2. 40-pin TQFN Package Dimensions Atmel LED Driver-MSL3162 7 Pin Descriptions Table 3. Pin Descriptions 8 PIN NAME PIN NUMBER FBI1, FBI2, FBI3 37, 39, 1 Efficiency Optimizer feedback inputs When using a common LED voltage over multiple MSL3162s, connect FBIs and FBOs in a chain, with the first FBI grounded and the last FBO controlling the external power source. For standalone operation, connect FBI to GND. FBO1, FBO2, FBO3 38, 40, 2 Efficiency Optimizer feedback outputs FBO controls the external regulator to dynamically adjust the LED voltage for optimal efficiency. When using a common LED voltage over multiple MSL3162s, connect FBIs and FBOs in a chain, with the first FBI grounded and the last FBO driving the feedback node of an external power source. CGND 3, 16 Signal ground Connect all CGND and GND pins to system GND and to the exposed pad, EP, using short, wide traces as close to the MSL3162 as possible GND 15, 31 Power ground Connect all GND and CGND pins to system GND and to the exposed pad, EP, using short, wide traces as close to the MSL3162 as possible PHI 4 Phase synchronization input Drive PHI with an external signal from 40Hz to 10kHz to synchronize the MSL3162 PWM dimming to the signal at PHI. Connect PHI to GND if unused. GSC 5 Gate shift clock input GSC sets the PWM dimming resolution. Drive GSC with the video signal gate shift clock up to 5MHz. Connect GSC to GND if unused. PWM 6 PWM dimming input Drive PWM with a pulse-width modulated signal with a duty ratio ranging from 0% to 100% and frequency from 20Hz to 50kHz to control the brightness of all LED strings. STR0 to STR15 7 - 14, 17 - 24 STR0 to STR15 LED string current sink outputs Connect the cathode end of each series LED string to one of STR0 to STR15. Connect unused outputs to GND, and disable unused strings using the master control registers. FLTB 25 Fault indication output (open drain, active low) FLTB sinks current to GND whenever the MSL3162 detects a fault. Once a fault is detected, FLTB remains low until the fault registers have been read. AD1, AD0 26, 29 I²C slave ID selection inputs AD0 and AD1 select the I²C slave address used. Connect AD0 and AD1 to either GND, VDD, SCL, or SDA to select the slave ID. SCL 27 I²C serial clock input SCL is the I²C serial interface clock input. SDA 28 I²C serial data I/O SDA is the I²C serial interface data I/O N/C 30, 32 ILED 33 Maximum LED current control input Connect a resistor from ILED to GND to set the full-scale LED string current. A 34.8kΩ resistor to GND sets a 60mA sink current through each LED string. EN 34 Enable input (active high) Drive EN high to turn on the MSL3162, and drive it low to turn it off. For automatic start-up, connect EN to VIN. PIN DESCRIPTION Factory connection. Leave unconnected. Atmel LED Driver-MSL3162 Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface PIN NAME PIN NUMBER VIN 35 Supply voltage input Connect the 5V ±10% supply to VIN. Bypass VIN to GND with a 10µF or greater ceramic capacitor VDD 36 2.5V internal LDO regulator output VDD is the output of the internal regulator and powers internal logic. Bypass VDD to GND with a 1µF ceramic capacitor EP Exposed Pad PIN DESCRIPTION Power ground Connect the exposed pad, EP, to system GND and to the GND pins using short, wide traces Absolute Maximum Ratings Voltage (With Respect to GND) VIN, EN..................................................................................................................................................................................... -0.3V to +6V SDA, SCL, AD0, AD1, FLTB................................................................................................................................-0.3V to +5.5V PHI, GSC, PWM...................................................................................................................................................-0.3V to VIN +0.3V FBI1, FBI2, FBI3, ILED................................................................................................................................. -0.3V to VDD +0.3V VDD, FBO1, FBO2, FBO3.................................................................................................................................-0.3V to +2.75V STR0 to STR15.............................................................................................................................................................. -0.3V to +40V CGND...............................................................................................................................................................................-0.05V to +0.05V Current (Into Pin) VIN...................................................................................................................................................................................................................50mA GND........................................................................................................................................................................................................1700mA STR0 to STR15.................................................................................................................................................................................105mA All other pins...............................................................................................................................................................-20mA to 20mA Note 1. Pins 3, 15, 16, 31 and the exposed pad, EP, must all be connected to the system GND using short, wide traces Note 2. Pins 30 and 32 must be left open circuit Continuous Power Dissipation at 70°C 40-pin, 6mm x 6mm QFN (see Note 8, Note 9)................................................................................................. 2963mW Ambient Operating Temperature Range, TA.................................................................................. -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 Driver-MSL3162 9 Electrical Characteristics (Circuit of Figure 4, VVIN = 5V, VEN = 5V, default register settings of Table 5, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C) PARAMETER CONDITIONS AND NOTES MIN TYP MAX UNIT 4.5 5 5.5 V DC ELECTRICAL CHARACTERISTICS VIN operating supply voltage VIN operating supply current Run mode; all LED strings driven 7 20 mA VIN shutdown supply current Sleep mode; SDA, SCL, AD0, AD1, PWM, PHI, GSC at GND or VDD 20 25 µA 2.5 2.65 V VDD regulation voltage 2.35 Input high voltage SDA, SCL, AD0, AD1, PWM, PHI, GSC 0.7 x VDD V Input low voltage SDA, SCL, AD0, AD1, PWM, PHI, GSC 0.3 x VDD Input high voltage EN 1.2 V V Input low voltage EN 0.8 V Output low voltage SDA Sinking 6mA 0.4 V Output low voltage FLTB Sinking 6mA 0.6 V ILED regulation voltage IILED = 10µA 370 mV 0 140 μA 0 55 μA 3.6 μA 340 FBI_ feedback input current FBO_ feedback output current VFBO_ = 0 to 1.8V FBO_ feedback output current step size FBI_ = GND; TA = +25°C FBI_ input disable threshold (Note 10) LED string sink current STR0 to STR15 2.5 355 3 140 RILED = 34.8kΩ ±0.1%; ISTRn = 0x20; VSTRn = 1V; TA = +25°C 28.5 RILED = 34.8kΩ ±0.1%; ISTRn = 0x3F; VSTRn = 1V; TA = +25°C (Note 10) LED string sink current matching STR0 to STR15 RILED = 34.8kΩ ±0.1%; ISTRn = 0x20; VSTRn = 1V; LED string sink current maximum STR0 to STR15 RILED = 20.5kΩ; ISTRn = 0x3F (Note 8, Note 9, Note 10) Short circuit fault detection threshold TA = +25°C Thermal cutoff temperature (Note 10) 30 31.5 58.9 100 2.5 3.5 % mA 4.5 135 CONDITIONS AND NOTES mA mA 3 Input leakage PARAMETER mV V °C 10 µA MIN TYP MAX UNIT 18 20 22 MHz 10000 Hz AC ELECTRICAL CHARACTERISTICS OSC initial accuracy PHI frequency 10 OSCTRL = 0x04 (fOSC=20MHz); TA=25°C 40 Atmel LED Driver-MSL3162 Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface PARAMETER CONDITIONS AND NOTES MIN TYP MAX UNIT 5 MHz GSC frequency 0 High and low time PHI, GSC 40 PWM frequency 20 50000 Hz PWM duty cycle 0.5 100 % PHI DLL lock cycles PARAMETER (Note 10) SYMBOL ns PHI cycles 4 CONDITIONS AND NOTES MIN TYP MAX UNIT 1000 kHz I²C SWITCHING CHARACTERISTICS SCL clock frequency Bus timeout period STOP to START condition bus free time 1/tSCL tTIMEOUT Bus timeout disabled (Note 2) 0 OSCTRL = 0x04 (fOSC=20MHz); TA=25°C 27 OSCTRL = 0x00 to 0x07; fOSC=16 to 23MHz 30 33 600000 / fOSC ms tBUF 0.5 µs Repeated START condition hold time tHD:STA 0.26 µs Repeated START condition setup time tSU:STA 0.26 µs STOP condition setup time tSU:STOP 0.26 µs SDA data hold time tHD:DAT 5 ns SDA data valid acknowledge time tVD:ACK (Note 3) 0.05 0.55 µs SDA data valid time tVD:DAT (Note 4) 0.05 0.55 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 SDA, SCL fall time tF SDA, SCL rise time tR SDA, SCL input suppression filter period tSP (Note 5, Note 6) (Note 7, Note 10) 120 ns 120 ns 50 ns Note 1. All parameters are tested at TA=25°C unless otherwise noted. Specifications at temperature are guaranteed by design Note 2. 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 feature for DC operation Note 3. tVD:ACK = SCL low to SDA (out) low acknowledge time Note 4. tVD:DAT = minimum SDA output data-valid time following SCL low transition Note 5. A master device must internally provide an SDA hold time of at least 300ns to ensure an SCL low state Note 6. 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 7. MSL3162 includes input filters on SDA, SCL, AD0, and AD1 inputs that suppress noise less than 50ns Note 8. Subject to thermal dissipation characteristics of the device Note 9. When mounted according to JEDEC, JEP149, and JESD51-12 for a two-layer PCB, θJA = 18.6°C/W and θJC = 1.4°C/W Note 10.Guaranteed by design and characterization. Not production tested Atmel LED Driver-MSL3162 11 Block Diagram Figure 3. Atmel LED Driver-MSL3162 Block Diagram 12 Atmel LED Driver-MSL3162 Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface GND GND MSL3162BT 20 19 18 17 16 15 14 13 12 11 GND 30 29 28 27 26 25 24 23 22 21 N/C AD0 SDA SCL AD1 FLTB STR15 STR14 STR13 STR12 STR11 STR10 STR9 STR8 CGND GND STR7 STR6 STR5 STR4 EP 1 2 3 4 5 6 7 8 9 10 GND FBI3 FBO3 CGND PHI GSC PWM STR0 STR1 STR2 STR3 C2 1 F GND N/C ILED EN VIN VDD FBI1 FBO1 FBI2 FBO2 SCL SDA FLTB VSYNC HSYNC PWM ENABLE GND GND RbottomB 35k GND GND +5V 31 32 33 34 35 36 37 38 39 40 VDD GND RbottomG C1 1 F RILED GND FB D1 CMPSH-3 D2 CMPSH-3 FB FB D3 CMPSH-3 VOUT RtopB DC-DC Converter DC-DC Converter VOUT Green LED String Blue LED String RtopG VOUT Red LED String DC-DC Converter RtopR RbottomR . Typical Application Circuit . Figure 4. Single Atmel LED Driver-MSL3162 Driving 60 Red, 60 Green, and 60 Blue LED Strings at 60mA Per String Atmel LED Driver-MSL3162 13 Detailed Description Internal Regulators and Enable Input Setting the Maximum LED String Current Built-in current control MOSFETs capable of withstanding up to 40V provide a compact solution. The Efficiency Optimizer circuit controls the LED voltage generated by an external DC-DC converter to minimize losses on the current control MOSFETs, improving efficiency and reducing driver power dissipation. The MSL3162 uses a high-speed, 1MHz I2C serial interface to control LED current, PWM dimming, and fault detection circuitry, making it an optimal solution for driving LED backlights for LCD panels. Onboard EEPROM allows default settings to be reconfigured for customization and settings to be saved at turn-off, eliminating the need to re-write settings at the next turn-on. The tiny, 6mm x 6mm QFN package enables a compact solution while maintaining high power dissipation. The maximum IILED current for the 16 LED strings STR0 to STR15 is set by external resistor RILED from the ILED pin to GND and is determined by the equation: Internal Regulators and Enable Input The MSL3162 includes an internal linear regulator that provides 2.5V supply voltage to power internal circuitry. Bypass VDD to GND with a 1μF or greater capacitor as close to the MSL3162 as possible. The EN input turns the MSL3162 on and off. To turn on the MSL3162, drive EN high with a 5V logic level, and drive EN low to turn it off. When EN is low, the MSL3162 enters low-power mode, reducing input current to 20µA, and turns off the serial interface. For automatic start-up, connect EN to VIN, allowing the MSL3162 to start automatically when voltage is applied. I ILED = 2050 R ILED where IILED is in mA and RILED is in kΩ. RILED=34.8kΩ sets the full-scale LED current to 58.9mA. RILED=20.5kΩ sets the full-scale LED current to 100mA, the maximum allowed. The currents for the 16 LED strings, STR0 to STR15, are reduced individually from full scale with 6-bit resolution using the LED string current control registers. If IILED for the 16 LED strings, STR0 to STR15, is chosen to be 30mA or lower (by selecting the value of external resistor RILED to be greater than 68.3kΩ), then the values programmed into the LED string current control registers must be limited to the range 0x00 to 0x1F. The full range of 0x00 to 0x3F is only available if IILED is set to be greater than 30mA by using an RILED value of 68.3kΩ or lower. LED String Current Control Each MSL3162 includes 16 current sink outputs, rated at 40V, each capable of sinking up to 100mA through a string of series connected LEDs. The internal Efficiency Optimizer circuit controls the LED voltage, minimizing power dissipated in the current sinks while maintaining high current-regulation accuracy. The MSL3162 power dissipation is limited to 2.1W. When using all 16 current sinks, maintain the total power dissipation within power dissipation limits. 14 Atmel LED Driver-MSL3162 Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface Efficiency Optimizer The Efficiency Optimizer improves power efficiency by adjusting each external LED power supply output voltage to the minimum required by the connected LED strings. It does this by injecting a current from the FBO output into the external LED power source voltage divider (Figure 5), thus lowering the LED supply voltage. The power supply's feedback voltage (internal reference voltage) must be 1.4V or less, and the voltage setting feedback network divider must be accessible. Use a Schottky diode (CMPSH-3 or similar) as shown to protect the power source against reverse current flow into the FBO pin, should the power supply circuit be powered before the MSL3162. Figure 5. Atmel LED Driver-MSL3162 FBO_Connection to Power Supply Voltage Divider Connecting an LED String Power Supply to an Efficiency Optimizer An LED string power supply uses a voltage divider (RTOP and RBOTTOM in Figure 6) to set its output voltage. The maximum output voltage is set by the voltage divider ratio and the power supply feedback regulation voltage per the equation: VFB = VOUT ( MAX ) * RBOTTOM R + RBOTTOM or VOUT ( MAX ) = VFB * TOP RBOTTOM RTOP + RBOTTOM VOUT(MAX) must exceed the maximum LED string voltage to ensure regulation, but ensure that VOUT(MAX) is always under the 40V maximum rating of the MSL3162’s LED string outputs, STR0 to STR15. The Efficiency Optimizer modifies the feedback network by injecting a current, IFBO, in the range of 0 to 45µA from the FBO output into the measurement node, FB. The minimum power supply output voltage is determined by the equation: VOUT ( MIN ) = VOUT ( MAX ) − (I F BOx ( MAX ) * RTOP ) where IFBOx(MAX) is the 45µA maximum output current from the Efficiency Optimizer output. From these equations, the equations to calculate the feedback resistors are: RTOP = V FB * VMAX − VMIN I FBO ( MAX Atmel LED Driver-MSL3162 ) and RBOTTOM = RTOP * VFB VOUT − VFB 15 Using Multiple Atmel LED Driver-MSL3162s to Control a Single Power Supply To use multiple MSL3162s to control a single power supply, connect the FBOx output of one MSL3162 to the FBIx input of another MSL3162 to form a chain(Figure 6). The Efficiency Optimizer decides whether the current at the FBIx input is less than what the FBOx output is programmed to. If the FBIx current is less than the programmed current, the FBIx current is transferred to the FBOx output. Otherwise, the programmed current is used at FBOx. The power supply output is, therefore, programmed to the minimum voltage required by all MSL3162s controlling it, and so all LED strings have sufficient voltage to maintain current regulation and power supply noise rejection. Figure 6. Cascade Multiple Atmel LED Driver-MSL3162s to Control a Common Power Supply The accuracy of the FBOx output current can degrade through each link of the FBIx/FBOx chain by as much as 2%. Therefore, the maximum output voltage correction current can drop by 2% per link. Calculate the worst-case FBOx current by the equation: I FBOx ( MAX = 45 µA * (0 .98 ) N −1 / MIN ) where IFBOx(MAX/MIN) is the worst-case (minimum) maximum FBOx output current, and N is the number of MSL3162 FBIx/ FBOx I/Os connected in series. Take care in laying out the traces for the Efficiency Optimizer FBIx/FBOx I/Os. If the FBIx input is not used, connect it to GND as close to the MSL3162 as possible. When routing the FBIx/FBOx signals across circuit boards, minimize the trace length as much as possible. Do not route the traces close to other traces with large variations in voltage or current because such traces may couple noise into the FBIx/FBOx I/Os. If these traces must be routed near noisy signals, shield them from noise by use of ground planes or guard traces. 16 Atmel LED Driver-MSL3162 Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface Register Map Summary The MSL3162 are controlled through an I2C interface through 82 registers (Table 4). Internal register addressing autoincrements through the register map. In some cases writing to unused register addresses can cause unintended behavior as shown in Table 4. It may be convenient to read or write to unused register address locations when accessing a block of registers sequentially which include unused registers. The power-up default values for all control registers are stored within on-chip user EEPROM, and any of these user EEPROM values may be changed by the user through the I2C interface. Table 4. Atmel LED Driver-MSL3162 Register Map REGISTER ADDRESS CONTROL0 CONTROL1 0x00 0x01 POWERCTRL 0x02 FLTSTATUS 0x03 FLTMASK0 0x04 FLTMASK1 0x05 OCSTAT0 0x06 OCSTAT1 0x07 SCSTAT0 0x08 SCSTAT1 0x09 STRFB0 STRFB1 STRFB2 0x0A 0x0B 0x0C STRFB3 0x0D FBOCTRL0 0x10 FBOCTRL1 0x11 FBODAC1 FBODAC2 FBODAC3 0x12 0x13 0x14 OSCCTRL 0x18 IGSCGEN IPHIGEN 0x1A 0x1B 0x1C 0x1D PWMCTRL0 0x20 PWMCTRL1 0x21 SYSTEMP 0x22 OTTEMP 0x23 OTSLOPE 0x24 Atmel LED Driver-MSL3162 FUNCTION REGISTER DATA D7 D6 STR7EN STR6EN LED string enables STR15EN STR14EN Fault SLEEP configuration Fault status, 0 SCDET global Fault enables, FLTEN7 FLTEN6 LED string FLTEN15 FLTEN14 monitoring Fault status, OC7 OC6 LED string open OC15 OC14 circuit Fault status, SC7 SC6 LED string short SC15 SC14 circuit LED string STRFB3[1:0] feed-back STRFB7[1:0] assignment to STRFB11[1:0] power supplies FBO1, FBO2, STRFB15[1:0] FBO3 Efficiency HLDSTEP[1:0] Optimizer SCCDLY[1:0] configuration DSTAT1 0 Efficiency Optimizer DAC DSTAT2 0 readback DSTAT3 0 Oscillator frequency GSC clock generator internal PHI clock generator internal PWM and HPSCREN GINTEN phase control configuration System temperature Over-temp derating threshold Over-temp derating slope D5 D4 D3 D2 D1 D0 STR5EN STR13EN STR4EN STR12EN STR3EN STR11EN STR2EN STR10EN STR1EN STR9EN STR0EN STR8EN SCEN OCEN 0* TOEN FBEN PHAEN OCDET 0 0 0 FBOICAL FLTDET FLTEN5 FLTEN4 FLTEN3 FLTEN2 FLTEN1 FLTEN0 FLTEN13 FLTEN12 FLTEN11 FLTEN10 FLTEN9 FLTEN8 OC5 OC4 OC3 OC2 OC1 OC0 OC13 OC12 OC11 OC10 OC9 OC8 SC5 SC4 SC3 SC2 SC1 SC0 SC13 SC12 SC11 SC10 SC9 SC8 STRFB2[1:0] STRFB6[1:0] STRFB10[1:0] STRFB1[1:0] STRFB5[1:0] STRFB9[1:0] STRFB0[1:0] STRFB4[1:0] STRFB8[1:0] STRFB14[1:0] STRFB13[1:0] STRFB12[1:0] FBCLDLY[1:0] FBSDLY[1:0] FBCFDLY[1:0] - - ACALPWM 0 0 0 0 0 0 - - ACALFSTR ACALEN TRIDIS FBODAC1[3:0] FBODAC2[3:0] FBODAC3[3:0] - OSC[2:0] IGSCGEN[7:0] IGSCGEN[15:8] IPHIGEN[7:0] IPHIGEN[15:8] PHIPOL OTPDIGEN - - PHIMINEN GSCMAXEN FSNOZSK - PWMMODE INTPHI 1* INTGSC SYSTEMP[7:0] OTTEMP[7:0] OTSLOPE[7:0] 17 Table 4. Atmel LED Driver-MSL3162 Register Map REGISTER ADDRESS HPSCR 0x25 0x26 0x27 0x28 0x29 FRATE 0x2A GINT ISTR0 0x2B 0x30 GSCMAX PHIMIN to ISTR15 0x3F PHDLY0 0x40 PHDLY15 PWM0 PWM15 to to 0x4F 0x50 0x5F E2ADDR 0x90 E2CTRLSTA 0x91 FUNCTION Max osc. cycles per GSC pulse Min GSC pulses over PHI period GSC divider PHI freq. multiplier Global intensity LED string 6-bit individual analog current settings LED string 8-bit individual PWM phase settings LED string 8-bit individual PWM intensity settings User EEPROM read/write access REGISTER DATA D7 D6 D5 D4 - D3 D2 GSCMAX[7:0] GSCMAX[15:8] PHIMIN[7:0] - - - - - - - - GINT[6:0] ISTR0[5:0] to - - ISTR15[5:0] D1 D0 PHIMIN[15:8] HPSCR[3:0] FRATE[4:0] PHDLY0[7:0] to PHDLY15[7:0] PWM0[7:0] to PWM15[7:0] Do not access address range 0x60 to 0x8F E2ADDR[6:0] E2BUSY BLDACT E2ERR SLVATCNT[1:0] RWCTRL[1:0] - Value written is stored and can be read back, but is not used internally. * These bits must remain set to the indicated state. Table 5. Atmel LED Driver-MSL3162 Register Power-up Defaults REGISTER NAME AND ADDRESS 0x00 0x01 0x02 0x04 0x05 0x0A to 0x0D CONTROL0 CONTROL1 POWERCTRL FLTMASK0 FLTMASK1 STRFB0 STRFB1 STRFB2 STRFB3 POWER-UP CONDITION D7 D6 D5 D4 D3 D2 D1 D0 LED strings STR0 to STR7 are disabled LED strings STR8 to STR15 are disabled Sleep mode Fault detection for LED strings STR0 to STR7 is disabled Fault detection for LED strings STR8 to STR15 is disabled 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 LED strings STR0 to STR7 are not monitored by the voltage optimizers FBO1, FBO2, FBO3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x10 FBOCTRL0 0x11 FBOCTRL1 Current sink error confirmation delay is 4µs FBO power supply correction delay is 2ms Efficiency Optimizer recalibration delay is 1s Efficiency Optimizer correction steps is 2 Auto calibration is disabled 0x18 OSCCTRL fOSC is 20MHz 0x1A 0x1B 0x1C 0x1D 18 REGISTER DATA IGSCGEN fGSC = fOSC IPHIGEN fPHI = fOSC / 8 Atmel LED Driver-MSL3162 Atmel LED Driver-MSL3162 16-string, RGB and White LED Drivers with Adaptive Power Control and 1MHz I2C/SMBus Serial Interface Table 5. Atmel LED Driver-MSL3162 Register Power-up Defaults REGISTER NAME AND ADDRESS POWER-UP CONDITION REGISTER DATA D7 D6 D5 D4 D3 D2 D1 D0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 System temperature, SYSTEMP, is 0°C 0 0 0 0 0 0 0 0 PWM is individually controlled by registers PWM0 to PWM15 GSC low- and high-frequency fault detection is disabled Over-temperature derating of LED strings is disabled PHI input falling edge synchronizes LED PWM Global intensity control uses GINT register GSC input is divided by value of GSC prescaler register External GSC signal at GSC input pin is used External PHI signal at PHI input pin is used PWM input pin is unused 0x20 PWMCTRL0 0x21 PWMCTRL1 0x22 SYSTEMP 0x23 OTTEMP Temperature compensation threshold, OTCOMP, is 255°C 1 1 1 1 1 1 1 1 0x24 OTSLOPE Over-temperature derating slope, OTSLOPE, is 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 0 0 0 1 1 1 0 0 0 0 1 1 1 0 0 0 1 1 Individual LED string current ILED = 7/63 times the full-scale current set by external resistor RILED 0 0 0 0 0 1 1 1 Individual LED string phase delay tDLYx = 0 0 0 0 0 0 0 0 0 Individual LED string PWM duty ratio DPWM = 1/256 = 0.39% 0 0 0 0 0 0 0 0 User EEPROM 7-bit address = 0x00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x25 0x26 0x27 0x28 0x29 0x2A 0x2B 0x30 to 0x3F 0x40 to 0x4F 0x50 to 0x5F HPSCR FRATE GINT ISTR0 to ISTR15 PHDLY0 to PHDLY15 PWM0 to PWM15 0x90 E2ADDR 0x91 GSCMAX PHIMIN Maximum GSC pulse count is 65536 (0xFFFF) Minimum PHI pulse count is 0 Internal GSC clock is GSC input pin frequency PHI multiplier is 1 Global intensity PWM duty ratio GINT = 16/64 = 25% E2CTRLSTA User EEPROM read/write is disabled Atmel LED Driver-MSL3162 19 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. 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