intersil Manuals

ISL6401 Synchronizing Current Mode PWM for Subscriber Line Interface Circuits (SLICs)

The ISL6721 is a low power, single-ended pulse width modulating (PWM) current mode controller designed for a wide range of DC/DC conversion applications including boost, flyback, and isolated output configurations.

The ISL6722A and ISL6723A are low power, single-ended pulse width modulating (PWM) current mode controllers designed for a wide range of DC/DC conversion applications including boost, flyback, and isolated output configurations. They offer adjustable operating frequency, adjustable soft-start, and other features.

The ISL6840, ISL6841, ISL6842, ISL6843, ISL6844, ISL6845 family of adjustable frequency, low power, pulse width modulating (PWM) current mode controllers is designed for a wide range of power conversion applications including boost, flyback, and isolated output configurations. Features include low operating current, 60µA start-up current, adjustable operating frequency to 2MHz, and high peak current drive capability with 20ns rise and fall times.

The ISL884xA is a high performance drop-in replacement for the popular 28C4x and 18C4x PWM controllers suitable for a wide range of power conversion applications including boost, flyback, and isolated output configurations. Its fast signal propagation and output switching characteristics make this an ideal product for existing and new designs. Features include 30V operation, low operating current, 90μA start-up current, adjustable operating frequency to 2MHz, and high peak current drive capability with 20ns rise and fall times.

ISL8843 is a single-ended current mode PWM controller from ISL company, suitable for a wide range of power conversion applications, including boost, flyback, and isolated output configurations, rated voltage 30V, operating current 90uA, rise and fall time 20ns, adjustable frequency 2MHz

The ISL6740, ISL6741 family of adjustable frequency, low power, pulse width modulating (PWM) voltage mode (ISL6740) and current mode (ISL6741) controllers is designed for a wide range of power conversion applications using half-bridge, full bridge, and push-pull configurations. These controllers provide an extremely flexible oscillator that allows precise control of frequency, duty cycle, and deadtime. 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.

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 parallel.

ISL6742 is a high performance dual-edge (PWM) controller featuring advanced synchronous rectification control and current limiting thresholds. It can be used in both current and voltage mode control methods. ISL6742 has complementary PWM outputs for synchronous rectification control. Using external control voltage, these complementary outputs can be dynamically advanced or delayed. Its excellent current sensing circuit uses a sample-and-hold method to provide a precise average current signal. Suitable for average current limiting protection, this method eliminates the limitations of peak current limiting methods, and is also suitable for equalizing circuits and average current mode control. This advanced BiCMOS design not only supports a tunable oscillator with a frequency up to 2MHz, but also has internal overtemperature protection, precise dead time control and resonance delay control. In addition, when jump pulses may occur, multi-phase pulse suppression can ensure corresponding output pulses at low duty cycles.

ISL6744 is a low cost, primary side, double-ended controller intended for applications using full and half-bridge topologies for unregulated DC/DC converters. It is a voltage-mode PWM controller designed for half-bridge and full-bridge power supplies. It provides precise control of switching frequency, adjustable soft-start, precise deadtime control with deadtimes as low as 35ns, and overcurrent shutdown. Low start-up and operating currents allow for easy biasing in both AC/DC and DC/DC applications. This advanced BiCMOS design features low start-up and operating currents, adjustable switching frequency up to 1MHz, 1A FET drivers, and very low propagation delays for a fast response to overcurrent faults.

ISL6745 is a low-cost, dual-ended controller that is primarily used in full-bridge and half-bridge topologies for power and line-regulated bus converters. The device features precise switching frequency control, adjustable soft start, and overcurrent shutdown protection. Additionally, the ISL6745 can precisely adjust the MOSFET non-overlap dead time down to 35 ns, allowing power designers to optimize the efficiency of open-loop bus converters. The ISL6745 also includes a voltage control input suitable for closed-loop PWM control and line-voltage feed-forward control.

ISL6551 is a zero voltage switching (ZVS) full-bridge PWM controller designed by Intersil for isolated power systems. This part implements a unique control algorithm for fixed-frequency ZVS current mode control, yielding high efficiency with low EMI. The two lower drivers are PWM-controlled on the trailing edge and employ resonant delay while the two upper drivers are driven at a fixed 50% duty cycle. This IC integrates many features in both 6x6 mm2 QFN and 28-lead SOIC packages to yield a complete and sophisticated power supply solution. Control features include programmable soft-start for controlled start-up, programmable resonant delay for zero voltage switching, programmable leading edge blanking to prevent false triggering of the PWM comparator due to the leading edge spike of the current ramp, adjustable ramp for slope compensation, drive signals for implementing synchronous rectification in high output current, ultra high efficiency applications, and current share support for paralleling up to 10 units, which helps achieve higher reliability and availability as well as better load regulation.

ISL6752 is a high performance, low pin count zero voltage (ZVS) full bridge pulse width (PWM) controller. This controller can realize ZVS operation by starting at a fixed 50% duty cycle of the upper switch and adjusting the pulse width at the trailing edge of the lower switch. The ISL6752 has complementary PWM outputs for synchronous rectification control. With external control voltage, these complementary outputs can be dynamically advanced or delayed. This advanced BiCMOS design not only supports precise dead time control and resonant delay control, but also has an adjustable oscillator with a frequency up to 2MHz. In addition, when a jump pulse may occur, multi-phase pulse suppression can ensure corresponding output pulses at a low duty cycle.

ISL6753 is a high-performance, low-pin-count alternative, zero-voltage switching (ZVS) full-bridge PWM controller. Like the ISL6551, it achieves ZVS operation by driving the upper bridge FETs at a fixed 50% duty cycle while the lower bridge FETS are trailing-edge modulated with adjustable resonant switching delays. Compared to the more familiar phase-shifted control method, this algorithm offers equivalent efficiency and improved overcurrent and light- load performance with less complexity in a lower pin count package. This advanced BiCMOS design features low operating current, adjustable oscillator frequency up to 2MHz, adjustable soft-start, internal over temperature protection, precision deadtime and resonant delay control, and short propagation delays. Additionally, Multi-Pulse Suppression ensures alternating output pulses at low duty cycles where pulse skipping may occur.

The ISL6729 is a single-ended current mode PWM controller from ISL company. It is designed for power conversion applications based on a microcontroller or other device that can generate a digital clock signal at the desired switching frequency. The device has 5V operating voltage, 1A MOSFET drive capability, 400µA startup current, 30ns propagation delay current sense to output, fast transient response, 2MHz switching frequency, 1nF output load 20ns rise and fall times, maximum duty cycle determined by clock input duty cycle, tight tolerance current limit threshold and other features.