EVALUATION KIT AVAILABLE MAX17505 4.5V-60V, 1.7A, High-Efficiency, Synchronous Step-Down DC-DC Converter With Internal Compensation General Description Benefits and Features The MAX17505/MAX17505S high-efficiency, high- Eliminates External Components and Reduces Total voltage, synchro nously rectified step-down converter with Cost dual integrated MOSFETs operates over a 4.5V to 60V No Schottky-Synchronous Operation for High input. It delivers up to 1.7A and 0.9V to 90%V output Efficiency and Reduced Cost IN voltage. Built-in compensation across the output voltage Internal Compensation for Stable Operation at Any range eliminates the need for external components. The Output Voltage feedback (FB) regulation accuracy over -40NC to +125NC All-Ceramic Capacitor Solution: Ultra-Compact is 1.1%. The device is available in a compact (4mm x Layout with as Few as Eight External Components 4mm) TQFN lead(Pb)-free package with an exposed pad. Reduces Number of DC-DC Regulators to Stock Simulation models are available. Wide 4.5V to 60V Input Voltage Range 0.9V to 90%V Output Voltage IN The device features a peak-current-mode control Delivers Up to 1.7A Over Temperature architecture with a MODE feature that can be used to 100kHz to 2.2MHz Adjustable Frequency with operate the device in pulse-width modulation (PWM), External Synchronization pulse-frequency modulation (PFM), or discontinuous- MAX17505S Allows Higher Frequency Of Operation conduction mode (DCM) control schemes. PWM operation Available in a 20-Pin, 4mm x 4mm TQFN Package provides constant frequency operation at all loads, and is Reduces Power Dissipation useful in applications sensitive to switching frequency. PFM operation disables negative inductor current and Peak Efficiency > 90% additionally skips pulses at light loads for high efficiency. PFM and DCM Modes for High Light-Load Efficiency DCM features constant frequency operation down to Shutdown Current = 2.8FA (typ) lighter loads than PFM mode, by not skipping pulses but Operates Reliably only disabling negative inductor current at light loads. Hiccup-Mode Current Limit and Autoretry Startup DCM operation offers efficiency performance that lies Built-In Output-Voltage Monitoring (Open-Drain between PWM and PFM modes. The MAX17505S offers RESET Pin) Resistor-Programmable EN/UVLO Threshold a lower minimum on-time that allows for higher switching frequencies and a smaller solution size. Adjustable Soft-Start and Prebiased Power-Up High Industrial -40C to +125C Ambient Operating A programmable soft-start feature allows users to reduce Temperature Range/-40C to +150C Junction input inrush current. The device also incorporates an Temperature Range output enable/undervoltage lockout pin (EN/UVLO) that allows the user to turn on the part at the desired input- voltage level. An open-drain RESET pin provides a delayed power-good signal to the sys tem upon achieving successful regulation of the output voltage. Applications Ordering Information appears at end of data sheet. Industrial Power Supplies Distributed Supply Regulati on Base Station Power Supplie s Wall Transformer Regulatio n High -Voltage Single-Board Systems General-Purpose Point-of-L oad 19-6907 Rev 2 5/17MAX17505 4.5V-60V, 1.7A, High-Efficiency, Synchronous Step-Down DC-DC Converter With Internal Compensation Absolute Maximum Ratings (Note 1) V to PGND .........................................................-0.3V to +65V SGND to PGND ....................................................-0.3V to +0.3V IN EN/UVLO to SGND ...............................................-0.3V to +65V LX Total RMS Current ...........................................................4A LX to PGND................................................-0.3V to (V + 0.3V) Output Short-Circuit Duration ....................................Continuous IN BST to PGND ........................................................-0.3V to +70V Continuous Power Dissipation (T = +70C) (multilayer board) A BST to LX .............................................................-0.3V to +6.5V TQFN (derate 30.3mW/C above T = +70C) ......2424.2mW A BST to V ...........................................................-0.3V to +65V Junction Tempera ture ......................................................+150C CC FB, CF, RESET, SS, MODE, SYNC, Storage Tempera ture Range .............................-65NC to +160C RT to SGND .....................................................-0.3V to +6.5V Lead Temperature (soldering, 10s) .................................+300C V to SGND .......................................................-0.3V to +6.5V Soldering Temperature (reflow) .......................................+260C CC 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 Information PACKAGE TYPE: 20 TQFN Package Code T2044+4 Outline Number 21-0139 Land Pattern Number 90-0409 THERMAL RESISTANCE, FOUR-LAYER BOARD Junction to Ambient ( ) 33C/W JA Junction to Case ( ) 2C/W JC For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a +, , or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 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. Note 1: Junction temperature greater than +125C degrades operating lifetimes. Electrical Characteristics (V = V = 24V, R = 40.2kI (500kHz), C = 2.2F, V = V = V = V = 0V, LX = SS = RESET = IN EN/UVLO RT VCC PGND SGND MODE SYNC open, V to V = 5V, V = 1V, T = -40C to +125C, unless otherwise noted. Typical values are at T = +25C. All voltages are BST LX FB A A referenced to SGND, unless otherwise noted.) (Note 2) 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) 2.8 4.5 IN-SH EN/UVLO V = 1V, MODE = RT = open 118 A FB I Q PFM V = 1V, MODE = open 162 FB Input Quiescent Current I DCM mode, V = 0.1V 1.16 1.8 Q-DCM LX mA Normal switching mode, f = 500kHz, V SW FB I 9.5 Q PWM = 0.8V www.maximintegrated.com Maxim Integrated 2