4.5V to 36V, 4.25A, High-Efficiency, Synchronous Step-Down DC-DC Converter

The MAX17634x is a high-efficiency, high-voltage, synchronous step-down DC-DC converter with integrated MOSFETs operating over an input-voltage range of 4.5V to 36V. It can deliver up to 4.25A current. The MAX17634 is available in three variants: MAX17634A, MAX17634B, and MAX17634C. The MAX17634A and MAX17634B are fixed 3.3V and fixed 5V output voltage parts, respectively. The MAX17634C is an adjustable output voltage (from 0.9V up to 90% of VIN) part. Built-in compensation across the output voltage range eliminates the need for external components.

The MAX17634x features peak-current-mode control architecture. The device can be operated in forced pulse-width modulation (PWM), pulse-frequency modulation (PFM), or discontinuous-conduction mode (DCM) to enable high efficiency under full-load and lightload conditions. The MAX17634x offers a low minimum on time that allows high switching frequencies and a smaller solution size.

The feedback voltage regulation accuracy over -40°C to +125°C for the MAX17634x is ±1.3%.The device is available in a compact 20-pin (4mm x 4mm) TQFN package. Simulation models are available.

Applications

* Industrial Control Power Supplies * General-Purpose Point-of-Load * Distributed Supply Regulation * Base Station Power Supplies * Wall Transformer Regulation * High-Voltage, Single-Board Systems

* Reduces External Components and Total Cost

* No Schottky–Synchronous Operation * Internal Compensation Components * All-Ceramic Capacitors, Compact Layout

* Reduces Number of DC-DC Regulators to Stock

* Wide 4.5V to 36V Input * Adjustable Output Range from 0.9V up to 90% of VIN * 400kHz to 2.2MHz Adjustable Frequency with External Synchronization * Available in a 20-Pin, 4mm x 4mm TQFN Package

* Reduces Power Dissipation

* Peak Efficiency of 94% * PFM and DCM Modes Enable Enhanced Light-Load Efficiency * Auxiliary Bootstrap Supply (EXTVCC) for Improved Efficiency * 2.8μA Shutdown Current

* Operates Reliably in Adverse Industrial Environments

* Hiccup-Mode Overload Protection * Adjustable and Monotonic Startup with Prebiased Output Voltage * Built-in Output-Voltage Monitoring with RESET (Active Low) * Programmable EN/UVLO Threshold * Overtemperature Protection * High Industrial -40°C to +125°C Ambient Operating Temperature Range/ -40°C to +150°C Junction Temperature Range