EVALUATION KIT AVAILABLE Click here for production status of specific part numbers. MAX17634A/MAX17634B/ 4.5V to 36V, 4.25A, High-Efficiency, MAX17634C Synchronous Step-Down DC-DC Converter General Description Benefits and Features The MAX17634x is a high-efficiency, high-voltage, synchro- Reduces External Components and Total Cost nous step-down DC-DC converter with integrated MOSFETs No SchottkySynchronous Operation operating over an input-voltage range of 4.5V to 36V. It can Internal Compensation Components deliver up to 4.25A current. The MAX17634 is available in All-Ceramic Capacitors, Compact Layout three variants: MAX17634A, MAX17634B, and MAX17634C. Reduces Number of DC-DC Regulators to Stock The MAX17634A and MAX17634B are fixed 3.3V and fixed Wide 4.5V to 36V Input 5V output voltage parts, respectively. The MAX17634C is Adjustable Output Range from 0.9V up to 90% of V IN an adjustable output voltage (from 0.9V up to 90% of V ) IN 400kHz to 2.2MHz Adjustable Frequency with part. Built-in compensation across the output voltage range External Synchronization eliminates the need for external components. Available in a 20-Pin, 4mm x 4mm TQFN Package The MAX17634x features peak-current-mode control Reduces Power Dissipation architecture. The device can be operated in forced pulse- Peak Efficiency of 94% width modulation (PWM), pulse-frequency modulation (PFM), or discontinuous-conduction mode (DCM) to enable high PFM and DCM Modes Enable Enhanced Light- efficiency under full-load and lightload conditions. The Load Efficiency MAX17634x offers a low minimum on time that allows high Auxiliary Bootstrap Supply (EXTVCC) for Improved switching frequencies and a smaller solution size. Efficiency 2.8A Shutdown Current The feedback voltage regulation accuracy over -40C to +125C for the MAX17634x is 1.3%.The device is Operates Reliably in Adverse Industrial Environments available in a compact 20-pin (4mm x 4mm) TQFN package. Hiccup-Mode Overload Protection Simulation models are available. Adjustable and Monotonic Startup with Prebiased Output Voltage Applications Built-in Output-Voltage Monitoring with RESET Industrial Control Power Supplies Programmable EN/UVLO Threshold General-Purpose Point-of-Load Overtemperature Protection Distributed Supply Regulation High Industrial -40C to +125C Ambient Operating Base Station Power Supplies Temperature Range/-40C to +150C Junction Wall Transformer Regulation Temperature Range High-Voltage, Single-Board Systems Ordering Information appears at end of data sheet. Typical Application Circuit V IN 6.5V36V C1 2 x 4.7F EN/UVLO IN RT BST L1 C5 R5 8.2H 0.1F MODE/SYNC V 51.1k OUT LX 5V, 4.25A C4 INTVCC C3 2 x 47F MAX17634B FB 2.2F SGND EXTVCC C2 EP 5600pF SS fSW : 400kHz PGND RESET L1: 8.2H (XAL6060-822ME) C1: 4.7F/50V/X7R/1206 (GRM31CR71H475KA12) C4: 47uF/10V/X7R/1210 (GRM32ER71A476ME15) 19-100572 Rev 0 6/19MAX17634A/MAX17634B/ 4.5V to 36V, 4.25A, High-Efficiency, MAX17634C Synchronous Step-Down DC-DC Converter Absolute Maximum Ratings IN to PGND ...........................................................-0.3V to +40V PGND to SGND ....................................................-0.3V to +0.3V EN/UVLO to SGND ....................................-0.3V to (V + 0.3V) LX Total RMS Current ........................................................4.7A IN LX to PGND................................................-0.3V to (V + 0.3V) Output Short-circuit duration .....................................Continuous IN EXTVCC to SGND ...............................................-5.5V to +6.5V Continuous Power Dissipation (Multilayer Board) (T = +70C, A BST to PGND .....................................................-0.3V to +46.5V derate 38.5mW/C above +70C.) ..........................3076.9mW BST to LX .............................................................-0.3V to +6.5V Operating Temperature Range (Note1) ...............-40C to 125C BST to INTVCC .....................................................-0.3V to +40V Junction Temperature ....................................... -40C to +150C FB to SGND (MAX17634A and MAX17634B) .....-5.5V to +6.5V Storage Temperature Range ............................ -65C to +150C FB to SGND (MAX17634C) .................................-0.3V to +6.5V Lead Temperature (soldering, 10s) .................................+300C SS, MODE/SYNC, RESET, INTVCC, RT to SGND ....-0.3V to +6.5V Soldering Temperature (reflow) .......................................+260C Note 1: Junction temperature greater than +125C degrades operating lifetimes 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 TQFN PACKAGE CODE T2044+4C Outline Number 21-100172 Land Pattern Number 90-0409 Thermal Resistance, Four-Layer Board (Note 2) Junction to Ambient ( ) 26C/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. Note 2: Package thermal resistances were obtained using the MAX17634 evaluation kit with no airflow Maxim Integrated 2 www.maximintegrated.com