Atmel LED Driver-MSL2100 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting Datasheet Brief Atmel LED Driver-MSL2100 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting General Description The Atmel® LED Driver MSL2100 compact, highpower LED string driver uses external MOSFETs to provide up 1A per string, with current accuracy and matching better than ±1%. The MSL2100 drives eight parallel strings of LEDs, and offers fault detection and management of open and short circuit LEDs. The MSL2100 features a 1MHz I2C serial interface. The interface supports video frame-by-frame LED string intensity control for up to 16 interconnected devices, allowing active area dimming when used for video displays. The advanced PWM engine synchronizes with the video signal, and offers phase shifted string drive, virtually eliminating waterfall noise and motion blur. The MSL2100 adaptively controls up to three DC-DC converters, which power the LED strings, using patented Atmel's Driver Adaptive SourcePower™ technology. These Efficiency Optimizers minimize power use while maintaining LED current accuracy, and allow up to 16 interconnected devices to automatically negotiate the optimum power supply voltages. A unique combination of peak current control and pulse width dimming management offers simple full-screen brightness control, versatile area dimming, and a consistent white point. LED string current is set for each string using a current sense (FET source) resistor. LED current is also digitally controlled for all eight LED strings. Global string drive pulse width is adjusted with a 6-bit global intensity register, and individual string pulse width is modulated with 8-bit control. Additionally, the MSL2100 optionally throttles back the PWM on time of all strings when the temperature of the LEDs exceeds a programmable threshold. The MSL2100 monitors for string open circuit, LED short circuit, loss-of-sync and over temperature faults, and provides a hardware fault output to notify the MCU. Detailed fault status and control are available through the serial interface. Additionally, the MSL2100 includes an on-chip EEPROM that allows the power-up default register settings to be customized via the serial interface. The MSL2100 is offered in a 6 x 6 x 0.85mm, 48-pin QFN package, and operates over a -40°C to +85°C temperature range. Applications • Edge-lit LED Backlit TVs • High-contrast Monitors • Medical and Industrial Displays • High-power LED Arrays • Multi-string LED Lighting • Solid-State Lighting (SSL) Ordering Information 2 PART DESCRIPTION PACKAGE MSL2100BR 8-Ch LED driver 48 pin, 6x6x0.85mm QFN Atmel LED Driver-MSL2100 Atmel LED Driver-MSL2100 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting Key Features • 8-bit PWM String Dimming • ±1% Current Accuracy and Current Balance • Fast, 1MHz I2C/SMBus Interface Supports up to 16 Devices per Bus • Video Frame (VSYNC) and Line (HSYNC) Sync Inputs • 4-Bit Adaptive Power Correction Maximizes Efficiency of up to Three Power Supplies • Sync Loss Detectors Optionally Disable LED Strings • External MOSFETs allow >0.5A LED String Current • Drives up to Eight Parallel High Power LED Strings • Multiple MSL2100s Share String Supplies and Automatically Negotiate Optimum Voltages • Supports Adaptive, Real-time 2-D Area Dimming for Highest Dynamic Range LCD TVs and Monitors • Programmable String Phase Virtually Eliminates Motion Blur and Improves Efficiency • Global LED Intensity Control via Serial Interface • Supports Direct PWM Control of all LED Strings with a Single PWM Input Signal • Internal EEPROM Allows Custom Power-up Default Settings • String Open Circuit and LED Short Circuit Fault Detection • <1µA LED String off Leakage Current • External Resistors Set Individual String Peak Current • Programmable LED Over-temperature Compensation • Automatic Die Over-temperature Protection • I2C/SMBus Broadcast Mode Simplifies Configuration • -40°C To +85°C Operating Temperature Range • Lead-free, Halogen-free, RoHs-compliant Package Application Circuit Atmel LED Driver-MSL2100 3 Quick Start Guide The MSL2100 controls eight strings of series-connected LEDs at up to 1A per string, and up to sixteen devices may share the serial interface. The MSL2100 FET gate drive output is optimized for FETs requiring no more than 10nC of charge. The MSL2100 PWM engine generates the PWM signal that drives the strings or, optionally, accepts an external PWM signal. How Many LEDs and Drivers? The MSL2100 drives eight strings of series-connected LEDs using external N-channel MOSFETs and current sense resistors. The LED drive capability (maximum number of LEDs per string) is limited only by the MOSFETs and the LED string power supplies, not by the MSL2100. Up to 16 MSL2100s may share an I2C/SMBus serial interface, with both individual and broadcast (all MSL2100s on a bus) addressing. The high LED drive power of the MSL2100 makes it suitable for large LCD TV and monitor backlights, as well as for LED signage and general lighting. LEDs, String Power Supplies, and the Efficiency Optimizer The MSL2100 features three Efficiency Optimizer outputs that dynamically adjust the LED string power supplies to the minimum voltage necessary to drive the LED strings, minimizing power use while assuring accurate LED current flow. The Efficiency Optimizers feature an input that allows up to 16 devices to be connected in a chain configuration. When implemented, the chains automatically negotiate, control and optimize the string power supplies for all LED strings driven by each chain. 4 The power supplies can use any topology that employs external feedback resistors with a maximum feedback voltage of 1.5V, and are typically DC-DC boost converters. The Efficiency Optimizers rely on close matching of the LEDs connected to a string supply; the better the matching, the better the overall efficiency. Differences between Atmel LED Driver-MSL2100 and MSL3082 The MSL2100 includes three independent Efficiency Optimizer circuits to control three separate string supplies (for RGB LEDs for example). The MSL3082 includes a single Efficiency Optimizer, is more suited for single-color LEDs, and is ideal for driving white backlight LEDs in an LCD monitor or TV application. Timing, PWM, Intensity Controls, and Synchronization The PWM LED drive signals synchronize to video frame timing via the PHI input, and to pixel timing via the GSC input. Suitability for LED backlight architectures is shown in Table 1 and Table 2. Area LED dimming for direct backlighting is supported for contrast and color gamut improvement. With area dimming, motion blur is reduced by setting each LED string’s PWM phasing to synchronize string off times with the LCD update timing. Also, the individual PWM intensity registers for eight LED strings are updated with only 92 I2C/SMBus clocks. Sixteen drivers (128 LED strings) update in 1.47ms with a 1MHz bus speed, offering area dimming support for frame rates up to 640Hz. Atmel LED Driver-MSL2100 Atmel LED Driver-MSL2100 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting Table 1. Atmel LED Driver-MSL2100 LED Common Backlight Drive Architectures BACKLIGHT TYPE 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 White LED - direct back-lit Yes - LED strip phasing Higher contrast ratio (area dimming) RGB LED - direct back-lit Yes - LED strip phasing Higher contrast ratio and color gamut White LED - four sides edge-lit One or more MSL2100 per Efficiency Optimized supply Table 2. Atmel LED Driver-MSL2100 Timing and LED Intensity Control Capability LED INENSITY CONTROL RESOLUTION Individual LED string current External resistors set maximum current for each LED string, up to at least 500mA Individual LED string current 6-bit ISTR registers reduce string current from maximum set by global resistor Global LED string pulse width 6-bit GINT register or PWM input (accepts 20Hz To 50kHz, 0% to 100% duty cycle) Individual LED string pulse width 8-bit PWM registers set individual string pulse width Global temperature derating 6-bit temperature pulse width derating individually applied to each string Total LED string pulse width control 10-bit LED string pulse width computed from global and individual pulse width settings Atmel LED Driver-MSL2100 5 PWM GSC PHI N/C CGND CGND CGND N/C GND EN VDD VIN Package Pin-out - Atmel LED Driver-MSL2100-TB 48 47 46 45 44 43 42 41 40 39 38 37 FLTB 5 32 G6 FBI1 6 31 S6 FBO1 7 MSL2100-TB 30 D5 FBI2 8 (TOP VIEW) 29 G5 FBO2 9 28 S5 FBI3 10 27 D4 FBO3 11 26 G4 GND 12 25 S4 13 14 15 16 17 18 19 20 21 22 23 24 D3 33 D6 G3 4 S3 AD0 D2 34 S7 G2 3 S2 SDA D1 35 G7 G1 2 S1 SCL D0 36 D7 G0 1 S0 AD1 Figure 1. 48-pin, 6mm x 6mm x 0.85mm QFN (0.4mm pin pitch) with Exposed Pad Figure 2. 48-pin TQFN Package Dimensions 6 Atmel LED Driver-MSL2100 Atmel LED Driver-MSL2100 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting Pin Descriptions PIN NAME 1 AD1 I²C slave ID selection inputs AD1 and AD0 select the device I²C slave address. 2 SCL I²C serial clock input SCL is the I²C serial interface clock input. 3 SDA I²C serial data I/O SDA is the I²C serial interface data I/O. 4 AD0 I²C slave ID selection inputs AD0 and AD1 select the device I²C slave address. 5 FLTB Fault output (open drain, active low) FLTB sinks current to GND when the MSL2100 detects a fault. FLTB remains low until the fault registers have been read or EN is toggled low. 6 FBI1 Efficiency Optimizer input Connect FBI1 to FBO1 of the next device when chaining the Efficiency Optimizers. If unused, connect FBI1 to GND. 7 FBO1 Efficiency Optimizer output Connect FBO1 through a Schottky diode to the string power supply’s feedback node (Figure 4) or to FBI1 of the previous device (Figure 5). If unused, leave FBO1unconnected. 8 FBI2 Efficiency Optimizer input Connect FBI2 to FBO2 of the next device when chaining the efficiency optimizers. If unused, connect FBI2 to GND. 9 FBO2 Efficiency Optimizer output Connect FBO2 through a Schottky diode to the string power supply’s feedback node (Figure 4) or to FBI2 of the previous device (Figure 5). If unused, leave FBO2 unconnected. 10 FBI3 Efficiency Optimizer input Connect FBI3 to FBO3 of the next device when chaining the efficiency optimizers. If unused connect FBI3 to GND. 11 FBO3 Efficiency Optimizer output Connect FBO3 through a Schottky diode to the string power supply’s feedback node (Figure 4) or to FBI3 of the previous device (Figure 5). If unused, leave FBO3 unconnected. 12, 40 GND Power ground Connect GND to system ground, to CGND, and to EP with short, wide traces. 13, 16, 19, 22, 25, 28, 31, 34 S0 - S7 String 0 thru 7 source sense inputs Connect Sn to the source of external MOSFETn and to the current sense resistor for LED stringn. The full-scale LED current is reached when 500mV is across the current sense resistor. 14, 17, 20, 23, 26, 29, 32, 35 G0 - G7 String 0 thru 7 external MOSFET gate drive outputs Connect Gn to the gate of external MOSFETn. 15, 18, 21, 24, 27, 30, 33, 36 D0 - D7 String 0 thru 7 external MOSFET drain sense inputs Connect Dn to the drain of external MOSFETn through a 10MΩ resistor. 37 VIN Supply voltage input Connect a 12V ±10% supply to VIN. Bypass VIN to GND with a 1µF ceramic capacitor placed close to VIN. 38 VDD Internal 2.5V regulator capacitor connection Bypass VDD to GND with a 10µF ceramic capacitor placed close to the device. Atmel LED Driver-MSL2100 DESCRIPTION 7 PIN NAME DESCRIPTION 39 EN Enable input (active high) Drive EN high to turn on the MSL2100, and drive it low to turn it off. For automatic startup, connect EN to VIN through a 100kΩ resistor. 41, 45 N/C No internal connection. Recommended to leave open. 42, 43, 44 CGND 46 PHI Phase synchronization input Drive PHI with an external signal from 40Hz to 10kHz to synchronize the PWM dimming to the signal at PHI. Connect PHI to GND if unused. 47 GSC Gate shift clock input Drive GSC with the gate shift clock of the video signal, up to 5MHz. GSC sets the resolution of PWM dimming. Connect GSC to GND if unused. 48 PWM PWM input Drive PWM with a pulse-width-modulated signal with a duty cycle of 0% to 100% and frequency of 20Hz to 50kHz to control the brightness of all LED strings. Exposed pad EP Connect to ground Connect CGND to system ground, to GND, and to EP using short, wide traces. Power ground Connect EP to system ground, GND, and CGND using short, wide traces. EP offers thermal relief to the die. Absolute Maximum Ratings Voltage (With Respect to GND) VIN, EN, D0-D7, G0-G7............................................................................................................................................... -0.3V to +16V SDA, SCL, AD0, AD1, FLTB.......................................................................................................................................-0.3V to +5.5V PHI, GSC, PWM, S0-S7, FBI1, FBI2, FBI3, FBO1, FBO2, FBO3............................. -0.3V to (VDD + 0.3V) VDD.............................................................................................................................................................................................-0.3V to +2.75V Current (Into Pin) VIN....................................................................................................................................................................................................................... 50mA GND................................................................................................................................................................................................................-500mA All other pins................................................................................................................................................................................................20mA Continuous Power Dissipation (See Note 8, Note 9) 48-pin, 6mm x 6mm x 0.85mm QFN (derate 45.5mW/°C above 70°C)................................ 2500mW 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 8 Atmel LED Driver-MSL2100 Atmel LED Driver-MSL2100 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting Electrical Characteristics (Circuit of Figure 3, VIN = 12V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VIN = 12V, TA = +25°C) PARAMETER CONDITIONS AND NOTES MIN TYP MAX UNIT 10.8 12.0 13.2 V 25.0 32.5 mA 10 20 μA 2.5 2.6 V DC ELECTRICAL CHARACTERISTICS VIN operating supply voltage VIN operating supply current All drivers on at 100% duty, I²C serial interface idle VIN shutdown supply current EN = 0, all digital inputs tied to VDD or GND VDD regulation voltage 2.3 Input high voltage SDA, SCL, AD0, AD1 2.31 V Input low voltage SDA, SCL, AD0, AD1 0.9 Input high voltage PHI, GSC, PWM 1.8 V Input low voltage PHI, GSC, PWM 0.7 Input high voltage EN 0.9 1.36 Input low voltage EN 50 Input quiescent current EN 1 Sinking 6mA V mV 20 0.4 S0 thru S7 regulation resolution V V 0.7 Input hysteresis EN SDA, FLTB output low voltage V μA V % of Full Scale 1 Open circuit detect voltage 7.3 8.3 9.0 V Short circuit detect voltage 6.5 7.8 9.0 V D0 thru D7 leakage current Voltage under 9V 0.1 Voltage between 9V to 16V 15 G0 thru G7 maximum gate drive voltage 10 G0 thru G7 gate drive current Current sense regulation voltage G0 thru G7 output current slew rate -20 Atmel LED Driver-MSL2100 20 mA 488 500 508 mV ISTRn = 0x1F 235 250 255 mV Current rising (Note 7, Note 8) 10 Current falling (Note 7, Note 8) 10 Up to FBOn maximum output current FBOn current step size FBOn feedback output current maximum V ISTRn = 0x3F Thermal cut-off temperature FBIn to FBOn current transfer error μA VFBO�= 0 to 1.8V 35 mA/µs 135 °C ±2 % 3 μA 45 55 μA 9 PARAMETER CONDITIONS AND NOTES MIN TYP 20 MAX UNIT 22 MHz AC ELECTRICAL CHARACTERISTICS fOSC OSCCTRL = 0x04 (fOSC=20MHz); TA=25°C 18 PHI frequency fPHI (Note 7) 40 10,000 Hz GSC frequency fGSC (Note 7) 5 MHz PWM frequency fPWM PWMDIRECT = PWMEN = 1 20 50,000 Hz PWMDIRECT = PWMEN = 1 0 100 % OSC initial accuracy PWM duty cycle PHI DLL lock cycles PHI Cycles 4 PARAMETER CONDITIONS AND NOTES MIN Bus timeout disabled (Note 1) 0 OSCCTRL = 0x04 (fOSC=20MHz); TA=25°C 27 TYP MAX UNIT 1,000 kHz 33 ms I²C SWITCHING CHARACTERISTICS SCL clock frequency Bus timeout period 1/tSCL tTIMEOUT 30 STOP to START condition bus free time tBUF 0.5 µs Repeated START condition hold time tHD:STA 0.26 µs Repeated START condition set-up time tSU:STA 0.26 µs STOP condition set-up time tSU:STOP 0.26 µs SDA data hold time tHD:DAT 15 ns SDA data valid acknowledge time tVD:ACK (Note 2) 0.05 0.55 µs (Note 3) 0.05 0.55 µs SDA data valid time tVD:DAT 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 4, Note 5) (Note 6) 50 120 ns 120 ns ns Note1. 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 Note2. tVD:ACK = SCL low to SDA (out) low acknowledge time Note3. tVD:DAT = minimum SDA output data-valid time following SCL low transition Note4. A master device must internally provide an SDA hold time of at least 300ns to ensure an SCL low state Note5. 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 Note6. The MSL2100 includes input filters on SDA, SCL, AD0, and AD1 inputs that suppress noise less than 50ns Note7. Parameter is guaranteed by design, and is not production tested Note8. Subject to thermal dissipation characteristics of the device Note9. When mounted according to JEDEC JEP149 and JESD51-12 for a one-layer PCB, θJA = 22°C/W and θJC = 1.3°C/W 10 Atmel LED Driver-MSL2100 Atmel LED Driver-MSL2100 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting Block Diagram Atmel LED Driver-MSL2100 11 Atmel LED Driver-MSL2100 Typical Application Circuit Figure 3. Typical Application Circuit 12 Atmel LED Driver-MSL2100 Atmel LED Driver-MSL2100 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting Detailed Description The MSL2100 is a highly integrated, flexible, multi-string LED driver that uses external MOSFETs to allow high LED string currents and includes power supply control for three supplies to maximize efficiency. The driver optionally connects to a video subsystem to offer easy synchronization for use in LCD TV backlight applications. Up to sixteen devices may be connected together to drive a large number 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 on-chip 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 factory programmed EEPROM values are changeable through the serial interface if a different power-up condition is desired. The device interfaces to an MCU via the I2C/SMBus interface. The robust 1MHz I2C/SMBus interface supports up to sixteen devices on the bus, and is fast enough to support area dimming for 16 interconnected devices. While typically the LED drive PWM signal is internally generated by the PWM engine, the device also accepts an external direct PWM drive signal applied to the PWM input to set the duty cycle and the frequency of the LED drive signals. When using the PWM engine, the MSL2100 allows phase spreading of the LED drive signals, which helps reduce the transient load on the LED power supplies. Phase spreading is not supported for direct PWM drive. The PWM frequency of the drivers is easily synchronized to an external video signal applied to PHI. Typically, the VSYNC signal from the video system is used as the PHI input. A frame-rate multiplier (1x to 16x) processes this signal for use by the PWM engine. The on time of each string is individually programmed via the device registers, providing a peak resolution of 10 bits when using the on-chip PWM generator. The actual resolution Atmel LED Driver-MSL2100 of the PWM frequency depends on the ratio of the GSC frequency (typically provided by a systems HSYNC signal) to the PHI frequency because the on time of a string is programmed as a function (8-bit count) of the number of GSC cycles. This count can be further scaled by a 6-bit global intensity register, when enabled. The GSC clock is also used to precisely set each string’s phase delay to be synchronized with its physical position relative to the video frame. Additionally, the MSL2100 features programmable temperature compensation, which throttles back the PWM on time of all strings when the temperature of the LEDs exceeds a programmable threshold. The Efficiency Optimizers control a wide range of different external DC-DC and AC-DC converter architectures. Multiple drivers in a system communicate in real time among themselves to select an optimized operating voltage for the LEDs. This allows design of the power supplies for the worst case forward voltage (Vf) of the LEDs without concern about excessive power dissipation issues. During the start-up sequence, the MSL2100 automatically reduces the power supply voltage to the minimum required to keep the LEDs in current regulation. The devices are configured to periodically perform this optimization to compensate for changes in LED forward voltage, and to assure continued optimum power savings. Internal Regulators and Enable Input The MSL2100 includes an internal linear regulator powered from VIN that provides 2.5V, VDD, to power the internal circuitry. Bypass VDD to GND with a 10μF or greater capacitor. The enable input, EN, turns the VDD regulator on and off. To turn on the MSL2100, force EN high with a 5V logic level, and force EN low to turn it off. When EN is low, the MSL2100 enters low-power mode, and the serial interface is ignored. Toggling EN low also clears all fault registers and releases FLTB. Faults re-establish if the conditions that generated them persist. 13 Setting LED String Currents The maximum string current, ILED, for each string is set by a resistor, RSn, connected to ground from the source terminal of the external string drive MOSFET. The feedback threshold is 500mV. Determine the resistor value using: R Sn = 0 .5 ohms. I LED , where ILED is in amperes and RSn is in For example, a full-scale LED current of 500mA returns RSn = 1.00Ω. The current for the LED strings is individually reduced from the full-scale resistor set value with 6-bit resolution using ISTRn, the string current control registers 0x10 through 0x1F. Connecting an LED String Power Supply to an Efficiency Optimizer Output The MSL2100 is designed to control up to three external LED string power supplies that use voltage dividers (RTOP and RBOTTOM in Figure 4) to set the output voltage, and whose regulation feedback voltage is not more than 1.5V. The Efficiency Optimizer improves power efficiency by injecting a current of between 0 and 45µA into the voltage dividers of the external power supplies, dynamically adjusting their outputs 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: where Vf(MIN) and Vf(MAX) are the LED minimum and maximum forward voltage drops at the peak current set by RSn (page_). For example, if the LED data are Vf(MIN) = 3.5V and Vf(MAX) = 3.8V, and ten LEDs are used in a string, then the total minimum and maximum voltage drops across a string are 35V and 38V, respectively. Adding an allowance of 0.5V for the string drive MOSFET headroom brings VOUT(MIN) to 35.5V and VOUT(MAX) to 38.5V. Then, determine RTOP using: RTOP = VOUT ( MAX ) − VOUT ( MIN ) I FBOn ( MAX ) , where IFBOn(MAX) is the 45µA maximum output current of the Efficiency Optimizer outputs, FBO1, FBO2, and FBO3. Finally, determine RBOTTOM using: R BOTTOM = RTOP ∗ V FB VOUT ( MAX ) − VFB , where VFB is the regulation feedback voltage of the power supply. Place a Schottky diode (CMPSH-3 or similar) between FBOn and the supply’s feedback node to protect the MSL2100 against current flow into FBOn. VOUT ( MIN ) = (V f ( MIN ) ∗ [# ofLEDs ])+ 0.5 , and VOUT ( MAX ) = (V f ( MAX ) ∗ [# ofLEDs ])+ 0.5 , Figure 4. FBOn Connection to Power Supply Voltage Divider 14 Atmel LED Driver-MSL2100 Atmel LED Driver-MSL2100 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting Using Multiple Atmel LED Driver-MSL2100s to Control a Single Power Supply Cascade multiple MSL2100 devices into a chain configuration (Figure 5) with the FBIn of one device connected to the FBOn of the next. Connect the first FBOn to the power supply feedback resistor node through a CMPSH-3 or similar Schottky diode, and the unused FBIn input to ground as close to the MSL2100 as possible. The chained devices work together to ensure that the system operates at optimum efficiency. Note that the accuracy of the feedback chain has the potential to degrade through each link of the FBIn/FBOn chain by as much as 2%. Determine the worst case maximum FBOn current, IFBOn(MAX/MIN), using: IFBOn(MAX / MIN) = 45µA* (0.98)N-1 , where N is the number of MSL2100s connected in series. Use this result in the above RTOP resistor equation for the term IFBOn(MAX) instead of using the 45µA figure shown here. 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 and/or guard traces. Figure 5. Cascade Multiple Atmel LED Driver-MSL2100s to Control a Common Power Supply Atmel LED Driver-MSL2100 15 Register Map Summary Control the MSL2100 using the registers in the range 0x00 through 0x57 (Table 3). Two additional registers, 0x90 and 0x91, allow access to, and programming of, the EEPROM. 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 3. Atmel LED Driver-MSL2100 Register Map REGISTER AND ADDRESS CONTROL 0x00 FUNCTION LED string enables REGISTER DATA D7 D6 D5 D4 D3 D2 D1 D0 STR7EN STR6EN STR5EN STR4EN STR3EN STR2EN STR1EN STR0EN I2CTOEN FBOEN PHADLYEN 0X01 UNUSED POWERCTRL 0x02 Power control SLEEP - STRSCEN STROCEN PWMDIRECT OSCCTRL 0x03 Oscillator frequency - - - - - OTTEMP 0x04 Over-temp threshold OTTEMP[7:0] SYSTEMP 0x05 System temperature SYSTEMP[7:0] OTSLOPE 0x06 Over-temp derating OTSLOPE[7:0] FLTSTATUS* 0x07 Fault status, global PWMCTRL 0x08 OCSTAT* 0x09 String open circuit status SCSTAT* 0X0A GINT - PWM and phase control, GSCDIVEN configuration STRSCDET STROCDET OSCFREQ[2:0] - - - FBOCAL FLTDET GINTEN PHIPOL TDERATE PHIMINEN GSCMAXEN OVRFLOEN PWMEN OC7 OC6 OC5 OC4 OC3 OC2 OC1 OC0 LED short circuit status SC7 SC6 SC5 SC4 SC3 SC2 SC1 SC0 0x0B Global intensity - - GSCDIV 0x0C GSC divider - - - PHIMUL 0x0D PHI multiplier - - - STR03FBO 0x0E STR47FBO 0x0F String FBO enables ISTR0 0x10 to ISTR7 0x1F PHDLY0 0x20 to PHDLY7 16 0x2F Individual string current throttle Individual string phase delay settings GINT[6:0] - GSCDIV[3:0] PHIMUL[4:0] STR3FBO[1:0] STR2FBO[1:0] STR1FBO[1:0] STR0FBO[1:0] STR7FBO[1:0] STR6FBO[1:0] STR5FBO[1:0] STR4FBO[1:0] - - ISTR0[5:0] - - to - - ISTR7[5:0] PHDLY0[7:0] to PHDLY7[7:0] Atmel LED Driver-MSL2100 Atmel LED Driver-MSL2100 REGISTER AND ADDRESS PWM0 0x30 to PWM7 0x3F 0x40 GSCMAX PHIMIN 0x41 0x42 0x43 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting FUNCTION REGISTER DATA D7 D6 D5 D4 0x47 0x50 FBOCTRL1 0x51 GSCMAX[7:0] GSCMAX[15:8] PHIMIN[7:0] - - - - FBO2DAC* FBO3DAC* PHIMIN[15:8] UNUSED Individual string fault monitoring enables FLTEN7 FLTEN6 FLTEN5 FLTEN4 FLTEN3 FLTEN2 FLTEN1 FLTEN0 UNUSED Efficiency Optimizer configuration HDRMSTEP[1:0] STRSCCDLY[1:0] FBCLDLY[1:0] - FBSDLY[1:0] - 0X52 THRU 0X56 FBO1DAC* D0 PWM7[7:0] Max oscillator cycles between GSC Pulses 0x48 thru 0x4F FBOCTRL0 D1 to 0X44 THRU 0X46 FAULTEN D2 PWM0[7:0] Individual string pulse width settings Min GSC pulses over PHI period D3 - FBCFDLY[1:0] - ACALEN ICHKDIS UNUSED 0x57 Efficiency Optimizer DAC readback FBO1ACT - - - FBO1DAC[3:0] 0x58 Efficiency Optimizer DAC readback FBO2ACT - - - FBO2DAC[3:0] 0x59 Efficiency Optimizer DAC readback FBO3ACT - - - FBO3DAC[3:0] DO NOT ACCESS ADDRESS RANGE 0X5A TO 0X8F E2ADDR 0x90 E2CTRLSTA 0x91 User EEPROM read/write access E2BUSY E2ADDR[6:0] BLDACT E2ERR - - RWCTRL[1:0] * Read-only registers Atmel LED Driver-MSL2100 17 Register Power-up Defaults Register power-up default values are shown in Table 4. Table 4. Atmel LED Driver-MSL2100 Register Power-up Defaults REGISTER NAME ANDADDRESS 0x00 18 CONTROL POWER-UP CONDITION REGIASTERS INITIALIZED FROM EEPROM REGISTER DATA D7 D6 D5 D4 D3 D2 D1 D0 HEX All LED strings drive outputs are enabled 1 1 1 1 1 1 1 1 FF String phase delay enabled Efficiency Optimizer feedback output enabled I2C bus timeout enabled Direct PWM disabled String open circuit detection enabled String short circuit detection enabled Device awake 0 1 1 1 0 1 1 1 77 0x02 POWERCTRL 0x03 OSCCTRL Internal oscillator fOSC set to 20MHz 0 0 0 0 0 1 0 0 04 0x04 OTTEMP Over-temperature threshold is 90°C 0 1 0 1 1 0 1 0 5A 0x05 SYSTEMP System temperature set to 30°C 0 0 0 1 1 1 1 0 1E 0x06 OTSLOPE Over-temperature slope set to 50°C 0 0 1 1 0 0 1 0 32 0x08 PWMCTRL PWM operation enabled String on times truncated at end of frame GSC low frequency fault detection disabled PHI high frequency fault detection disabled Over-temperature derating of string on times enabled PWM frame synchronized to rising edge at PHI input GINT global intensity control enabled GSC input frequency division disabled 0 1 1 1 0 0 0 1 71 0x0B GINT Global intensity PWM duty cycle GINT = 15/64 = 23.4% 0 0 0 0 1 1 1 1 0F 0x0C GSCDIV GSC input frequency is divided by 2^0 0 0 0 0 0 0 0 0 00 0x0D PHIMUL PHI input frequency is multiplied by 1 0 0 0 0 0 0 0 1 01 0x0E STR03FBO 1 1 1 0 1 0 0 1 E9 0x0F STR47FBO All strings are monitored by the Efficiency Optimizer and are assigned to the FBO outputs as follows: FBO1: Strings 0 and 4 FBO2: Strings 1, 2, 5 and 6 FBO3: Strings 3 and 7 1 1 1 0 1 0 0 1 E9 0x10 0x17 ISTR0 thru ISTR7 0 0 1 0 0 0 0 0 20 Individual peak string current = 0 .5 R Sn ∗ 32 63 Atmel LED Driver-MSL2100 Atmel LED Driver-MSL2100 REGISTER NAME ANDADDRESS 8-string, High-power, White or RGB LED Drivers for TVs, Monitors, or Intelligent Solid-state Lighting POWER-UP CONDITION REGIASTERS INITIALIZED FROM EEPROM REGISTER DATA D7 D6 D5 D4 D3 D2 D1 D0 HEX 0x20 0x27 PHDLY0 thru PHDLY7 All string phase delays set to zero processed GSC cycles 0 0 0 0 0 0 0 0 00 0x30 0x37 PWM0 thru PWM7 All strings PWM settings equal 48 processed GSC cycles 0 0 1 1 0 0 0 0 30 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 00 Fault detection is enabled for all strings 1 1 1 1 1 1 1 1 FF 0 0 0 0 1 1 0 0 0C 0x40 GSCMAX Maximum GSC pulse count is 0 0x41 0x42 PHIMIN Minimum PHI pulse count is 0 0x43 0x47 FAULTEN 0x50 FBOCTRL0 Current source error confirmation delay is 4µs FBOn power supply settling time allowance is 8ms Efficiency Optimizer auto recalibration delay is 1s Efficiency Optimizer gives three steps for headroom 0x51 FBOCTRL1 Current source error detection enabled Auto recalibration disabled String short circuit confirmation delay is 4µs 0 0 0 0 0 0 0 0 00 0x90 E2ADDR User EEPROM 7-bit address = 0x00 0 0 0 0 0 0 0 0 00 0x91 E2CTRLSTA User EEPROM read/write disabled 0 0 0 0 0 0 0 0 00 Atmel LED Driver-MSL2100 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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