Top

High-Voltage, Step-Down DC-DC Controller in µMAX

High-Voltage (36V) Step-Down DC-DC Controller in µMAX

Product Details

The MAX1744/MAX1745 are step-down DC-DC controllers capable of handling up to 36V inputs. These parts use a proprietary current-limited control scheme for excellent light- and full-load efficiency, while their 330kHz (max) switching frequency permits small external components for space-critical applications. Operation to 100% duty cycle permits the lowest possible dropout voltage.

The MAX1744 contains an internal feedback network that provides a pin-selectable output voltage of either 3.3V or 5V. The MAX1745 uses an external feedback network to generate an adjustable output voltage between 1.25V and 18V.

The MAX1744/MAX1745 are available in a space-saving 10-pin µMAX® package.

Key Features

  • High-Voltage Operation (up to 36VIN)
  • Efficiency > 90%
  • Output Power Capability Exceeds 50W
  • 10-Pin µMax Package
  • Low-Dropout Voltage
  • 100% (max) Duty Cycle
  • 90µA Quiescent Current
  • 4µA Shutdown Current
  • Up to 330kHz Switching Frequency
  • Output Voltage
    • 5V or 3.3V (MAX1744)
    • Adjustable 1.25V to 18V (MAX1745)
  • Current-Limited Control Scheme

Applications/Uses

  • Automotive Electronics
  • FireWire®/IEEE® 1394
  • Industrial Control Systems
  • Telecom Systems
  • Wall-Cube-Powered Devices
Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 4.5
VIN (V) (max) 36
VOUT1 (V) (min) 3.3
VOUT1 (V) (max) 5
IOUT1 (A) (max) 10
Switch Type External
Preset VOUT (V) 5
Output Adjust. Method Preset
Resistor
# DC-DC Outputs 1
Switching Frequency (kHz) 330
Package/Pins UMAX/10
Budgetary
Price (See Notes)
$2.97 @1k
View More

Simplified Block Diagram

MAX1744, MAX1745: Typical Operating Circuit MAX1744, MAX1745: Typical Operating Circuit Zoom icon

Technical Docs

Design & Development

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

Description

The MAX1744 evaluation kit (EV kit) provides a selectable 3.3V or 5V output voltage from input as high as 36V. The MAX1744 operates up to 100% duty cycle, extending the usable input voltage range. The 100% duty cycle and a low 100mV current-sense level permit very low dropout voltages. The circuit is configured to deliver up to 2A of output current with greater than 90% conversion efficiency. The output current can be increased by changing the external components.

This EV kit is a fully assembled and tested circuit board. It can also be used to evaluate the MAX1745, which has an adjustable output voltage, by selecting feedback resistors R2 and R3.

View Details

Features

  • High Input Voltage (up to 36V)
  • Selectable 3.3V or 5V Output Voltage (MAX1744)
  • 1.25V to 18V Adjustable Output Voltage (MAX1745)
  • Low Dropout Voltage
  • 100% Maximum Duty Cycle
  • 2A Output Current
  • Up to 330kHz Switching Frequency
  • 4µA IC Shutdown Current
  • 10-Pin µMAX® Package
  • Fully Assembled and Tested

Description

The MAX1744 evaluation kit (EV kit) provides a selectable 3.3V or 5V output voltage from input as high as 36V. The MAX1744 operates up to 100% duty cycle, extending the usable input voltage range. The 100% duty cycle and a low 100mV current-sense level permit very low dropout voltages. The circuit is configured to deliver up to 2A of output current with greater than 90% conversion efficiency. The output current can be increased by changing the external components.

This EV kit is a fully assembled and tested circuit board. It can also be used to evaluate the MAX1745, which has an adjustable output voltage, by selecting feedback resistors R2 and R3.

View Details

Features

  • High Input Voltage (up to 36V)
  • Selectable 3.3V or 5V Output Voltage (MAX1744)
  • 1.25V to 18V Adjustable Output Voltage (MAX1745)
  • Low Dropout Voltage
  • 100% Maximum Duty Cycle
  • 2A Output Current
  • Up to 330kHz Switching Frequency
  • 4µA IC Shutdown Current
  • 10-Pin µMAX® Package
  • Fully Assembled and Tested

/en/design/design-tools/ee-sim.html?

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

Parameters

Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 4.5
VIN (V) (max) 36
VOUT1 (V) (min) 3.3
VOUT1 (V) (max) 5
IOUT1 (A) (max) 10
Switch Type External
Preset VOUT (V) 5
Output Adjust. Method Preset
Resistor
# DC-DC Outputs 1
Switching Frequency (kHz) 330
Package/Pins UMAX/10
Budgetary
Price (See Notes)
$2.97 @1k

Key Features

  • High-Voltage Operation (up to 36VIN)
  • Efficiency > 90%
  • Output Power Capability Exceeds 50W
  • 10-Pin µMax Package
  • Low-Dropout Voltage
  • 100% (max) Duty Cycle
  • 90µA Quiescent Current
  • 4µA Shutdown Current
  • Up to 330kHz Switching Frequency
  • Output Voltage
    • 5V or 3.3V (MAX1744)
    • Adjustable 1.25V to 18V (MAX1745)
  • Current-Limited Control Scheme

Applications/Uses

  • Automotive Electronics
  • FireWire®/IEEE® 1394
  • Industrial Control Systems
  • Telecom Systems
  • Wall-Cube-Powered Devices

Description

The MAX1744/MAX1745 are step-down DC-DC controllers capable of handling up to 36V inputs. These parts use a proprietary current-limited control scheme for excellent light- and full-load efficiency, while their 330kHz (max) switching frequency permits small external components for space-critical applications. Operation to 100% duty cycle permits the lowest possible dropout voltage.

The MAX1744 contains an internal feedback network that provides a pin-selectable output voltage of either 3.3V or 5V. The MAX1745 uses an external feedback network to generate an adjustable output voltage between 1.25V and 18V.

The MAX1744/MAX1745 are available in a space-saving 10-pin µMAX® package.

Simplified Block Diagram

MAX1744, MAX1745: Typical Operating Circuit MAX1744, MAX1745: Typical Operating Circuit 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