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

A High-Efficiency, High-Voltage, Synchronous Step-Down DC-DC Converter with Integrated MOSFETs

Product Details

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.

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 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

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
Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 4.5
VIN (V) (max) 36
VOUT1 (V) (min) 0.9
VOUT1 (V) (max) 32.4
IOUT1 (A) (max) 4.25
Switch Type Internal
Preset VOUT (V) -
Output Adjust. Method Preset
Resistor
Synchronous Switching? Yes
Power Good Signal Yes
# DC-DC Outputs 1
Switching Frequency (kHz) 400
2200
Design Tools EE-Sim
Package/Pins TQFN-CU/20
Budgetary
Price (See Notes)
$1.25 @1k
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Simplified Block Diagram

MAX17634A, MAX17634B, MAX17634C: Functional Diagram MAX17634A, MAX17634B, MAX17634C: Functional Diagram Zoom icon

Technical Docs

Design & Development

Click any title below to view the detail page where available.

Description

The MAX17634AEVKIT# 3.3V output evaluation kit (EV kit) provides a proven design to evaluate the MAX17634A high-voltage, high-efficiency, synchronous step-down DC-DC converter. The EV kit is preset for 3.3V output at load currents of 4.25A and features a 400kHz switching frequency for optimum efficiency and component size. The EV kit features an adjustable input undervoltage lockout, adjustable soft-start, open-drain active-low RESET signal, and external clock synchronization. EV kit specifications, settings, features and benefits are highlighted. The EV kit layout is optimized for thermal performance. For more details about the IC benefits and features, refer to the MAX17634 data sheet.

View Details

Features

  • Wide 4.5V to 36V Input Range
  • Programmed 3.3V Output, 4.25A Load Current
  • 400kHz Switching Frequency
  • EN/UVLO Input, Resistor-Programmable UVLO Threshold
  • Programmed 1ms Soft-Start Time
  • Selectable PWM, PFM, and DCM Modes
  • Open-Drain Active-low RESET Output Pulled Up to 5V of INTVCC
  • Provision for External Frequency Synchronization
  • Overcurrent and Overtemperature Protection
  • Proven PCB Layout
  • Fully Assembled and Tested

    Description

    The MAX17634BEVKIT# 5V output evaluation kit (EV kit) provides a proven design to evaluate the MAX17634B high-voltage, high-efficiency, synchronous step-down DC-DC converter. The EV kit is preset for 5V output at load currents of 4.25A and features a 400kHz switching frequency for optimum efficiency and component size. The EV kit features an adjustable input undervoltage lockout, adjustable soft-start, open-drain active-low RESET signal, and external clock synchronization. EV kit specifications, settings, features and benefits are highlighted. The EV kit layout is optimized for thermal performance. For more details about the IC benefits and features, refer to the MAX17634 data sheet.

    View Details

    Features

    • Wide 6.5V to 36V Input Range
    • Programmed 5V Output, 4.25A Load Current
    • 400kHz Switching Frequency
    • EN/UVLO Input, Resistor-Programmable UVLO Threshold
    • Programmed 1ms Soft-Start Time
    • Selectable PWM, PFM, and DCM Modes
    • Open-Drain Active-Low RESET Output Pulled Up To 5V of INTVCC
    • Provision for External Frequency Synchronization
    • Overcurrent and Overtemperature Protection
    • Proven PCB Layout
    • Fully Assembled and Tested

    Description

    The MAX17634CEVKIT# 5V output evaluation kit (EV kit) provides a proven design to evaluate the MAX17634C high-voltage, high-efficiency, synchronous step-down DC-DC converter. The EV kit is preset for 5V output at load currents of 4.25A and features a 400kHz switching frequency for optimum efficiency and component size. The EV kit features an adjustable input undervoltage lockout, adjustable soft-start, open-drain active-low RESET signal, and external clock synchronization. EV kit specifications, settings, features and benefits are highlighted. The EV kit also provides a good layout example, which is optimized for Conducted, Radiated EMI and thermal performance. For more details about the IC benefits and features, refer to the MAX17634 data sheet.

    View Details

    Features

    • Wide 6.5V to 36V Input Range
    • Programmed 5V Output, 4.25A Load Current
    • 400kHz Switching Frequency
    • EN/UVLO Input, Resistor-Programmable UVLO Threshold
    • Programmed 1ms Soft-Start Time
    • Selectable PWM, PFM, and DCM Modes
    • Open-Drain Active-Low RESET Output Pulled Up To 5V of INTVCC
    • Provision for External Frequency Synchronization
    • Overcurrent and Overtemperature Protection
    • Proven PCB Layout
    • Fully Assembled and Tested
    • Complies with CISPR22(EN55022) Class B Conducted and Radiated Emissions

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    Tools & Models

    EE-Sim: Design & Simulate MAX17634C

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    Support & Training

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    Parameters

    Parametric specs for Step-Down Switching Regulators
    VIN (V) (min) 4.5
    VIN (V) (max) 36
    VOUT1 (V) (min) 0.9
    VOUT1 (V) (max) 32.4
    IOUT1 (A) (max) 4.25
    Switch Type Internal
    Preset VOUT (V) -
    Output Adjust. Method Preset
    Resistor
    Synchronous Switching? Yes
    Power Good Signal Yes
    # DC-DC Outputs 1
    Switching Frequency (kHz) 400
    2200
    Design Tools EE-Sim
    Package/Pins TQFN-CU/20
    Budgetary
    Price (See Notes)
    $1.25 @1k

    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 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

    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

    Description

    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.

    Simplified Block Diagram

    MAX17634A, MAX17634B, MAX17634C: Functional Diagram MAX17634A, MAX17634B, MAX17634C: Functional Diagram Zoom icon

    Technical Docs

    Support & Training

    Search our knowledge base for answers to your technical questions.

    Filtered Search

    Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal