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4.2V–60V No-Opto Isolated Flyback Converter with Integrated FET

Reduce Solution Size and Component Count by Up to 30%

Product Details

Parametric specs for Isolated Power Supplies
VIN (V) (min) 4.2
VIN (V) (max) 60
Topology Flyback
Application (VIN) Base Station (24V)
Industrial (24V)
Networking (48V)
Power Over Ethernet (32-58V)
Switch Type Internal
Feedback Primary Side
Switching Frequency (kHz) 100-300
Oper. Temp. (°C) -40 to +125
Package/Pins TDFN-CU/12
Budgetary
Price (See Notes)
1.69
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Parameters

Parametric specs for Isolated Power Supplies
VIN (V) (min) 4.2
VIN (V) (max) 60
Topology Flyback
Application (VIN) Base Station (24V)
Industrial (24V)
Networking (48V)
Power Over Ethernet (32-58V)
Switch Type Internal
Feedback Primary Side
Switching Frequency (kHz) 100-300
Oper. Temp. (°C) -40 to +125
Package/Pins TDFN-CU/12
Budgetary
Price (See Notes)
1.69

Key Features

  • Reduces External Components and Total Cost
    • Eliminates the Optocoupler and Secondary-Side Error Amplifier
    • Up to 20% Space Savings
    • 76V, Low RDSON Integrated nMOSFET
    • Internal Loop Compensation (MAX17691A)
    • Built-In Soft-Start
  • Reduces Power Dissipation
    • > 90% Efficiency
    • Delivers up to 7.5W Output Power
    • Frequency Fold-Back Enables Enhanced Light-Load Efficiency
    • 2.5µA Shutdown Current
  • Supports Key System-Level Design Requirements
    • Frequency Dithering Supports Low-EMI, Spread-Spectrum Operation
    • Switching Frequency Synchronization to External Clock
    • Compliant with CISPR22 ClassB EMI Requirements
  • Operates Reliably in Adverse Environments
    • Output Diode Forward Voltage Temperature Compensation
    • Hiccup Current-Limit Protection
    • Programmable EN/UVLO Threshold
    • Input Overvoltage (OVI) Protection (MAX17691A)
    • Overtemperature Protection
    • High Industrial -40°C to +125°C Ambient Operating Temperature Range/ -40°C to +150°C Junction Temperature Range

Applications/Uses

  • Isolated Power Supplies
  • PLC I/O Modules
  • IGBT Gate Drive Supplies
  • Industrial and Telecom Applications

Description

Maxim's Rainier family of isolated power devices enable cooler, smaller, and simpler power-supply solutions. The MAX17691A/B is a high efficiency No-Opto integrated nMOSFET flyback converter that uses fixed frequency peak current mode control. The device senses the isolated output voltage directly from the primary-side flyback waveform during secondary-side rectifier conduction. No secondary- side error amplifier and optocoupler are required to provide an accurate, isolated, regulated output voltage, saving up to 20% of PCB space normally required for a traditional flyback converter.

The MAX17691A/B features a low RDSON, 76V, 170mΩ integrated nMOSFET primary switch and is designed to operate over a wide supply range from 4.2V to 60V. The switching frequency of the device is programmable from 100kHz to 350kHz. An EN/UVLO feature allows the user to turn ON/OFF the power converter precisely at the desired input voltage. Input overvoltage protection can be implemented using the OVI pin (MAX17691A only). Softstart limits inrush current at startup. The MAX17691A/B supports external clock synchronization to avoid low-frequency “beats” on the input bus in systems with multiple converters. The device also has programmable frequency dithering for low-EMI, spread-spectrum operation.

The MAX17691A/B allows temperature compensation for variations in the output rectifier diode forward voltage drop. The MAX17691A is internally compensated for loop stability, while the MAX17691B offers external loop compensation flexibility. The MAX17691A/B has robust hiccup- protection and thermal protection schemes, and is available in a space-saving 12-pin, 3mm x 3mm TDFN package with a temperature range from -40°C to +125°C.

Simplified Block Diagram

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 .