The ISL6740A is an enhanced ISL6740 PWM controller

featuring built-in voltage feed forward functionality. It is pin

and feature compatible with the ISL6740 double-ended pulse

width modulating (PWM) voltage-mode controller, allowing

easy drop-in replacement on existing designs.

Voltage feed forward compensates for input voltage variation

without intervention of the feedback control loop. It is

particularly useful in unregulated bus converters and DC

transformers where wide input voltage variation would

otherwise result in large output voltage swings.

In addition to voltage feed forward compensation, the

ISL6740A features an extremely flexible oscillator that allows

precise control of frequency, duty cycle, and deadtime.

Deadtimes of under 40ns are easily achievable.

This advanced BiCMOS design features low operating current,

adjustable switching frequency up to 1MHz, adjustable

soft-start, internal and external over-temperature protection,

fault annunciation, and a bidirectional SYNC signal that allows

the oscillator to be locked to paralleled units or to an external

clock for noise sensitive applications.

Features

• Input Voltage Feed Forward Compensation

• Precision Duty Cycle and Deadtime Control

• Adjustable Delayed Overcurrent Shutdown and Re-Start

• Adjustable Short Circuit Shutdown and Re-Start

• Adjustable Oscillator Frequency Up to 2MHz

• Bidirectional Synchronization

• Adjustable Input Undervoltage Lockout/Inhibit

• Tight Tolerance Voltage Reference Over Line, Load, and

Temperature

• Adjustable Soft-Start

• Fault Signal

• 95µA Startup Current

• Internal Over-Temperature Protection

• System Over-Temperature Protection Using a Thermistor or

Sensor

• Pb-free and ELV, WEEE, RoHS Compliant

Applications

• Telecom and Datacom Power

• Wireless Base Station Power

• File Server Power

• Industrial Power Systems

• DC Transformers and Bus Converters