EVALUATION KIT AVAILABLE MAX17521 60V, 1A, Dual-Output, High-Efficiency, Synchronous Step-Down DC-DC Converter General Description Benefits and Features The MAX17521 dual-output, high-efficiency, high-voltage, Reduces External Components and Total Cost synchronous step-down DC-DC converter with integrated No SchottkySynchronous Operation MOSFETs operates over a 4.5V to 60V input. The converter All-Ceramic Capacitors, Compact Layout can deliver up to 1A at each output. Each output is Reduces Number of DC-DC Regulators to Stock programmable from 0.9V to 92%V . The feedback voltage IN Wide 4.5V to 60V Input regulation accuracy over -40C to +125C is 1.7%. Each Output Adjustable From 0.9V to 92%V IN Pin-Selectable 560kHz or 300kHz Switching The MAX17521 uses peak-current-mode control. Each output can be operated in the pulse-width modulation Frequency Independent Input Voltage Pin for Each Output (PWM) or pulse-frequency modulation (PFM) control schemes. Reduces Power Dissipation The MAX17521 is available in a 24-pin (4mm x 5mm) Peak Efficiency > 90% PFM Mode Enables Enhanced Light-Load Efficiency TQFN package. Simulation models are available. 1A Shutdown Current Applications Operates Reliably in Adverse Industrial Environments Industrial Control Power Supplies Hiccup Mode Overload Protection CPU, DSP, or FPGA Power Adjustable Soft-Start Pin for Each Output Distributed Supply Regulation Built-In Output Voltage Monitoring with RESET for General-Purpose Point of Load Each Output Adjustable EN/UVLO Threshold for Each Output Ordering Information appears at end of data sheet. Monotonic Startup Into Prebiased Load Overtemperature Protection -40C to +125C Operation Typical Application Circuit VIN 7.5V60V C1 C2 2.2 F 2.2 F EN/UVLO1 V PGND1 PGND2 V EN/UVLO2 IN1 IN2 MODE1 MODE2 C16 V V CC1 CC2 C6 1 F 1 F SGND2 SGND1 MAX17521 RESET1 RESET2 V L1 L2 V OUT1 OUT2 22 H 15 H 5V, 1A 3.3V, 1A LX1 LX2 C3 C4 22 F 10 F R9 R1 54.9k 82.5k SS1 COMP1 FSEL SYNC COMP2 SS2 FB1 FB2 C8 C7 3300pF 3300pF R10 R5 R8 R2 20.5k 14k 19.1k 18.2k C12 C10 33pF 22pF C9 C11 2700pF 2700pF 19-7479 Rev 0 3/15MAX17521 60V, 1A, Dual-Output, High-Efficiency, Synchronous Step-Down DC-DC Converter Absolute Maximum Ratings V to PGND ......................................................-0.3V to +65V Output Short-Circuit Duration ....................................Continuous IN EN/UVLO to SGND ............................. -0.3V to (V + 0.3V) Operating Temperature Range ......................... -40C to +125C IN LX to PGND ......................................... -0.3V to (V + 0.3V) Junction Temperature ......................................................+150C IN FB , RESET , FSEL, MODE , Storage Temperature Range ............................ -65C to +160C COMP , V , SYNC, SS to SGND ..............-0.3V to +6V Lead Temperature (soldering, 10s) .................................+300C CC SGND to PGND ................................................-0.3V to +0.3V Soldering Temperature (reflow) .......................................+260C LX Total RMS Current ........................................................1.6A Continuous Power Dissipation (T = +70C) A (derate 28.6mW/C above +70C) (multilayer board) ....................................................2285.7mW 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. (Note 1) Package Thermal Characteristics Junction-to-Ambient Thermal Resistance ( ) ..............35C/W JA Junction-to-Case Thermal Resistance ( ..................1.8C/W JC) 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 = +24V, V = V = V = 0V, C = 2.2F, C = 1F, V = 1.5V, C = 0.01F, FB = 0.98 x V , IN SGND PGND FSEL IN VCC EN/UVLO SS FB-REG COMP = unconnected, LX = unconnected, RESET = unconnected. T = T = -40C to +125C, unless otherwise noted. Typical A J values are at T = +25C. All voltages are referenced to SGND , unless otherwise noted.) (Note 2) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS INPUT SUPPLY (V ) IN Input Voltage Range V 4.5 60 V IN Input Shutdown Current I V = 0V, shutdown mode 1 3.5 A IN-SH EN I V > 2V 135 260 A Q PFM MODE Input Switching Current V > 2V 5 V < 0.8V, FSEL MODE I mA Q PWM V = 0.8V V < 0.8V 3.7 COMP FSEL ENABLE/UVLO (EN ) V V rising 1.19 1.215 1.24 EN R EN V V falling 1.11 1.135 1.16 EN F EN EN Threshold V V EN - V falling, true shutdown 0.75 EN TRUESD EN Input Leakage Current I V = V = 60V, T = +25C 300 nA EN EN IN A FREQUENCY SELECTOR (FSEL) V V low level 0.8 FSELR FSEL FSEL Threshold V V V high level 2 FSELF FSEL FSEL Input Leakage Current I V = V , T = +25C -2.5 +2.5 A FSEL FSEL CC A MODE SELECTOR (MODE ) V V low level 1.9 V MODE R MODE MODE Threshold V V high level 2.5 MODE F MODE MODE Input Leakage Current I V = V , T = +25C 300 nA MODE MODE CC A Maxim Integrated 2 www.maximintegrated.com