DATASHEET ISL6721A FN6797 Rev.1.00 Flexible Single-Ended Current Mode PWM Controller Jul 24, 2018 The ISL6721A is a low power, single-ended Pulse-Width Features Modulating (PWM) current mode controller designed for 1A MOSFET gate driver a wide range of DC/DC conversion applications 100A startup current including Boost, Flyback, and isolated output configurations. Peak current mode control effectively Fast transient response with Peak Current Mode handles power transients and provides inherent control overcurrent protection. Other features include a low Adjustable switching frequency up to 1MHz power mode in which the supply current drops to less than 200A during overvoltage and overcurrent Bidirectional synchronization shutdown faults. The ISL6721A differs from the Low Power Disable mode ISL6721 in that the UVLO and UV thresholds have been Delayed restart from OV and OC shutdown faults modified. Adjustable slope compensation This advanced BiCMOS design features low operating current, adjustable operating frequency up to 1MHz, Adjustable soft-start adjustable soft-start, and a bidirectional SYNC signal Adjustable overcurrent shutdown threshold that allows the oscillator to be locked to an external clock for noise sensitive applications. Adjustable UV and OV monitors Leading edge blanking Related Literature For a full list of related documents, visit our website Integrated thermal shutdown ISL6721A product page 1% tolerance voltage reference Pb-Free (RoHS compliant) Applications Telecom and datacom power Wireless base station power File server power Industrial power systems Isolated buck and flyback regulators Boost regulators FN6797 Rev.1.00 Page 1 of 36 Jul 24, 2018ISL6721A Contents 1. Overview . 4 1.1 Typical Applications 4 1.2 Block Diagram 6 1.3 Ordering Information . 7 1.4 Pin Configurations . 7 1.5 Pin Descriptions . 8 2. Specifications 10 2.1 Absolute Maximum Ratings . 10 2.2 Thermal Information . 10 2.3 Recommended Operating Conditions . 10 2.4 Electrical Specifications 11 3. Typical Performance Curves . 14 4. Functional Description 15 4.1 Features 15 4.2 Oscillator . 15 4.3 Implementing Synchronization . 15 4.4 Soft-Start Operation . 15 4.5 Gate Drive 15 4.6 Slope Compensation 15 4.7 Overvoltage and Undervoltage Monitor 16 4.8 Overcurrent Operation . 17 4.9 Leading Edge Blanking 17 4.10 Fault Conditions 17 4.11 Ground Plane Requirements 17 5. Reference Design . 18 5.1 Circuit Element Descriptions 18 5.2 Design Criteria . 18 5.3 Transformer Design . 18 5.4 Selecting Power MOSFETs . 21 5.5 Output Filter Design . 22 5.6 Control Loop Design 23 5.7 Regulation Performance . 26 5.8 Waveforms 28 5.9 Component List 30 5.10 References . 32 FN6797 Rev.1.00 Page 2 of 36 Jul 24, 2018