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

Description

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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 V_IN) 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.

Key Features

• 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 V_IN
  • 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

Applications/Uses

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