New Industry Products

Peak-Current-Mode Controllers for Flyback and Boost Regulators

April 21, 2020 by Paul Shepard

The MAX17595/MAX17596/MAX17597 from Maxim Integrated Products is a family of peak-current-mode controllers for design of wide input-voltage flyback and boost regulators. The MAX17595 offers optimized input thresholds for universal input ac-dc power supplies and telecom dc-dc converters (36V to 72V input range). The MAX17596/MAX17597 offer input thresholds suitable for low-voltage dc-dc applications (4.5V to 36V). The MAX17597 implements a boost converter. All three controllers contain a built-in gate driver for external n-channel MOSFETs.

These peak-current-mode controllers are targeted for use in battery-powered applications, industrial and telecommunications power systems, universal-input offline ac-dc power supplies and wide-range dc-input flyback/boost battery chargers.

The MAX17595/96/97 house an internal error amplifier with 1% accurate reference, eliminating the need for an external reference. The switching frequency is programmable from 100kHz to 1MHz with an accuracy of 8%, allowing optimization of magnetic and filter components, resulting in compact and cost-effective power conversion.

For EMI-sensitive applications, the MAX17595/96/97 family incorporates a programmable frequency dithering scheme, enabling low-EMI spread-spectrum operation.

Users can start the power supply precisely at the desired input voltage, implement input overvoltage protection, and program soft-start time. A programmable slope compensation scheme is provided to ensure stability of the peak-current-mode control scheme.

Hiccup-mode overcurrent protection and thermal shutdown are provided to minimize dissipation in overcurrent and overtemperature fault conditions.

Key Features

  • Programmable Switching Frequency Allows Optimization of the Magnetic and Filter Components, Resulting in Compact, Cost-Effective, Efficient Isolated/Non-Isolated Power Supplies
    • 100kHz to 1MHz Programmable Switching Frequency with Optional Synchronization
    • Peak Current Mode Control Provides Excellent Transient Response
      • Offline (Universal Input AC) and Telecom (36V to 72V) Flyback Controller—MAX17595
      • DC-DC (4.5V to 36V) Flyback Controller—MAX17596
      • Nonsynchronous (4.5V to 36V) Boost PWM Controller—MAX17597
    • 3mm x 3mm TQFN Package
  • Programmable Frequency Dithering Enables Low-EMI Spread-Spectrum Operation
  • Integrated Protection Features Enhance System Reliability
    • Adjustable Current Limit with External Current-Sense Resistor
    • Fast Cycle-By-Cycle Peak Current Limiting
    • Hiccup-Mode Short-Circuit Protection
    • Overtemperature Protection
    • Programmable Soft-Start and Slope Compensation
    • Input Overvoltage Protection