EVALUATION KIT AVAILABLE High-Power LED Driver with Integrated MAX16834 High-Side LED Current Sense and PWM Dimming MOSFET Driver General Description Benefits and Features The MAX16834 is a current-mode high-brightness LED Integration Minimizes BOM for High-Brightness LED (HB LED) driver for boost, boost-buck, SEPIC, and high- Driver with a Wide Dimming Range Saving Space side buck topologies. In addition to driving an n-channel and Cost power MOSFET switch controlled by the switching con- Constant-Frequency, Peak Current-Mode Control troller, it also drives an n-channel PWM dimming switch to with Programmable Slope Compensation achieve LED PWM dimming. The MAX16834 integrates Integrated PWM Dimming MOSFET Driver all the building blocks necessary to implement a fixed-fre- 3000:1 PWM Dimming/Analog Dimming quency HB LED driver with wide-range dimming control. The MAX16834 features constant-frequency peak cur- Integrated High-Side Current-Sense Amplifier for rent-mode control with programmable slope compensa- LED Current Sense in Boost-Buck Converter tion to control the duty cycle of the PWM controller. Internal 7V Low-Dropout Regulator A dimming driver designed to drive an external n-chan- Simple Optimization for Efficiency, Board Space and nel MOSFET in series with the LED string provides Input Operating Range wide-range dimming control up to 20kHz. In addition to Supports Boost, Buck-Boost, SEPIC, and High- PWM dimming, the MAX16834 provides analog dim- Side Buck Topologies ming using a DC input at REFI. The programmable 100kHz to 1MHz Programmable High-Frequency switching frequency (100kHz to 1MHz) allows design Operation optimization for efficiency and board space reduction. A single resistor from RT/SYNC to ground sets the External Clock Synchronization Input switching frequency from 100kHz to 1MHz while an Wide Input Operating Voltage Range (4.75V to 28V) external clock signal at RT/SYNC disables the internal Works for Input Voltage > 28V with External oscillator and allows the MAX16834 to synchronize to Voltage Clamp on V for Boost Converter IN an external clock. The MAX16834s integrated high- 20-Pin TQFN-EP and TSSOP-EP Packages side current-sense amplifier eliminates the need for a Protection Features Increase System Reliability separate high-side LED current-sense amplifier in boost-buck applications. Programmable UVLO Programmable True Differential Overvoltage The MAX16834 operates over a wide supply range of 4.75V to 28V and includes a 3A sink/source gate driver Protection for driving a power MOSFET in high-power LED driver Fault Output (FLT) for Overvoltage, Overcurrent, applications. It can also operate at input voltages and Thermal-Warning Faults greater than 28V in boost configuration with an external voltage clamp. The MAX16834 is also suitable for DC- Simplified Application Circuit DC converter applications such as boost or boost- VIN buck. Additional features include external enable/ BOOST LED DRIVER disable input, an on-chip oscillator, fault indicator out- put (FLT) for LED open/short or overtemperature condi- LED+ tions, and an overvoltage protection sense input (OVP+) for true overvoltage protection. IN NDRV The MAX16834 is available in a thermally enhanced LEDs 4mm x 4mm, 20-pin TQFN-EP package and in a thermal- MAX16834 ly enhanced 20-pin TSSOP-EP package and is specified ON over the automotive -40C to +125C temperature range. OFF PWMDIM CS LED- ANALOG DIMOUT Applications REFI DIM Single-String LED LCD Backlighting PGND SENSE+ Automotive Rear and Front Lighting Projection System RGB LED Light Sources Architectural and Decorative Lighting (MR16, M111) Spot and Ambient Lights Ordering Information and Pin Configurations appear at end of data sheet. DC-DC Boost/Boost-Buck Converters 19-4235 Rev 5 1/15High-Power LED Driver with Integrated MAX16834 High-Side LED Current Sense and PWM Dimming MOSFET Driver Absolute Maximum Ratings IN, HV, LV to SGND................................................-0.3V to +30V V Short-Circuit Current to SGND Duration ...........................1s CC OVP+, SENSE+, DIMOUT, CLV to SGND ..............-0.3V to +30V Continuous Power Dissipation (T = +70C) A SENSE+ to LV........................................................-0.3V to +0.3V QFN, TQFN (derate 25.6mW/C* above +70C).........2051mW HV, IN to LV............................................................-0.3V to +30V TSSOP (derate 26.5mW/C above +70C) .....................2122mW OVP+, CLV, DIMOUT to LV......................................-0.3V to +6V Operating Temperature Range .........................-40C to +125C PGND to SGND .....................................................-0.3V to +0.3V Junction Temperature......................................................+150C V to SGND..........................................................-0.3V to +12V Storage Temperature Range .............................-65C to +150C CC NDRV to PGND...........................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C CC All Other Pins to SGND.............................................-0.3V to +6V Soldering Temperature (reflow) .......................................+260C NDRV Continuous Current................................................50mA *As per JEDEC51 standard (multilayer board). DIMOUT Continuous Current..............................................2mA Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Package Thermal Characteristics (Note 1) Junction-to-Ambient Thermal Resistance ( ) Junction-to-Case Thermal Resistance ( ) JA JC QFN, TQFN ........................................................................39C/W QFN, TQFN .....................................................................6C/W TSSOP .............................................................................37.7C/W TSSOP.............................................................................2C/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. Electrical Characteristics (V = V = 12V, V = 5V, V = V = V , C = 4.7F, C = 100nF, C = 100nF, R = 0.1 , IN HV UVEN LV PWMDIM SGND VCC LCV REF SENSE+ R = 10k, T = T = -40C to +125C, unless otherwise noted. Typical values are at T = +25C.) RT A J A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Voltage Range V 4.75 28 V IN Quiescent Supply Current I Excluding I 610 mA Q LED Shutdown Supply Current I V = 0V 30 60 A SHDN UVEN INTERNAL LINEAR REGULATOR (V ) CC Output Voltage V 0 I 50mA, 9.5V V 28V 6.3 7 7.7 V CC CC IN Dropout Voltage V I = 35mA (Note 2) 0.65 1V DO CC Short-Circuit Current V = 0V, V = 12V 80 300 mA CC IN LINEAR REGULATOR (CLV) 0 I 2mA, 6V V 28V, CLV HV Output Voltage (V V ) 4.7 5 5.3 V CLV - LV 6V V 22V (HV-LV) Dropout Voltage V I = 2mA, 0 V 23.3V (Note 3) 0.5 V DO CLV LV Short-Circuit Current V = 12V, V = 12V, V = 24V 2.2 10 mA CLV IN HV REFERENCE VOLTAGE (REF) Output Voltage V 0 I 1mA, 4.75V V 28V 3.625 3.70 3.775 V REF REF IN REF Short-Circuit Current V = 0V 30 mA REF UNDERVOLTAGE LOCKOUT/ENABLE INPUT (UVEN) UVEN On Threshold Voltage V 1.395 1.435 1.475 V UVEN THUP UVEN Threshold Voltage 200 mV Hysteresis Input Leakage Current I V = 0V 1 A LEAK UVEN PWMDIM PWMDIM On Threshold Voltage V 1.395 1.435 1.475 V PWMDIM www.maximintegrated.com Maxim Integrated 2