ISL6740A

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




Application

• Telecom and Datacom Power
• Wireless Base Station Power
• File Server Power
• Industrial Power Systems
• DC Transformers and Bus Converters




Pinout






Specifications

Supply Voltage, VDD . . . . . . . . . . . . . . . . . . . GND - 0.3V to +20.0V
OUTA, OUTB, Signal Pins . . . . . . . ... . . . . . . . . .GND - 0.3V to VREF
VREF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GND - 0.3V to 6.0V
Peak GATE Current . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . 0.5A
ESD Classification
Human Body Model (Per MIL-STD-883 Method 3015.7) . ..... .1500V
Charged Device Model (Per EOS/ESD DS5.3, 4/14/93) . ...... .1000V





Description

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.