Peak-Current-Mode Controllers for Flyback and Boost Regulators

The MAX17595/MAX17596/MAX17597 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 converters and telecom DC-DC (36V to 72V input range) power supplies. 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.

The MAX17595/MAX17596/MAX17597 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/MAX17596/MAX17597 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 ensuree 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. Applications

* Battery-Powered Applications * Industrial and Telecom Applications * Universal Input Offline AC-DC Power Supplies * Wide-Range DC-Input Flyback/Boost Battery Chargers

* 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