ISL6742 Intersil Corporation, ISL6742 Datasheet
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ISL6742
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ISL6742 Summary of contents
Page 1
... Data Sheet Advanced Double-Ended PWM Controller The ISL6742 is a high-performance double-ended PWM controller with advanced synchronous rectifier control and current limit features suitable for both current- and voltage-mode control methods. The ISL6742 includes complemented PWM outputs for synchronous rectifier (SR) control. The complemented outputs may be dynamically advanced or delayed relative to the main outputs using an external control voltage ...
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Functional Block Diagram VDD VREF UVLO OVER- TEMPERATURE PROTECTION GND VREF IOUT 4X OSCILLATOR CT RTD SS PWM STEERING LOGIC SAMPLE + AND HOLD - 1.00V OVER CURRENT COMPARATOR PWM COMPARATOR VREF + - SOFTSTART CONTROL VDD OUTA OUTB DELAY/ ...
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... C5 VIN VR1 C15 R13 Q4 T2 R17 Q2 C17 C14 R9 CR2 CR1 R8 U1 HIP2100 R7 VDD LO HB VSS ISL6742 C13 1 VREF 2 VERR 3 RTD RAMP IOUT R5 C8 R11 R6 R10 C9 R4 C11 C10 L1 Q5 C16 R16 Q6 R15 ...
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Typical Application - High Voltage Input Secondary Side Control Full-Bridge Converter VIN+ CR4 Q1 R13 Q5A Q5B C9 + 400 VDC C1 Q4 CR6 R12 Q7A Q7B C8 VIN- VREF T2 R21 Q15 CR1 CR2 SECONDARY BIAS ...
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... Charged Device Model (Per EOS/ESD DS5.3, 4/14/93 .1000V Operating Conditions Temperature Range ISL6742AAxx . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to 105°C Supply Voltage Range (Typical 9-16 VDC CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied ...
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... VERR to PWM Comparator Input Offset VERR to PWM Comparator Input Gain Common Mode (CM) Input Range OSCILLATOR Frequency Accuracy, Overall Frequency Variation with VDD Temperature Stability Charge Current Discharge Current Gain CT Valley Voltage CT Peak Voltage 6 ISL6742 TEST CONDITIONS V = 1.1V RAMP T = 25° 0.3V RAMP (Note 4) ...
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... This is the maximum duty cycle achievable using the specified values of RTD and CT. Larger or smaller maximum duty cycles may be obtained using other values for these components. See Equations 1-3. 6. Adjust VDD below the UVLO stop threshold prior to setting at 7V. 7 ISL6742 TEST CONDITIONS Static Value I ...
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... GND with a 0.1µF to 2.2µF low ESR capacitor The oscillator timing capacitor is connected between this pin and GND charged through an internal 200µA current source and discharged with a user adjustable current source controlled by RTD. 8 ISL6742 110 FIGURE 2. CT DISCHARGE CURRENT GAIN vs RTD CURRENT ...
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... Functional Description Features The ISL6742 PWM is an excellent choice for low cost bridge and push-pull topologies in applications requiring accurate duty cycle and deadtime control. With its many protection and control features, a highly flexible design with minimal external components is possible ...
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... – Soft-Start Operation The ISL6742 features a soft-start using an external capacitor in conjunction with an internal current source. Soft-start reduces component stresses and surge currents during start-up. Upon start-up, the soft-start circuitry limits the error voltage input (VERR value equal to the soft-start voltage. The output pulse width increases as the soft-start capacitor voltage increases ...
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... The average current control loop behaves much the same as the voltage control loop found in typical power supplies except it regulates current rather than voltage. The EA available on the ISL6742 may also be used as the voltage EA for the voltage feedback control loop rather than the current EA as described above. An external op-amp may be used as either the current or voltage EA providing the circuit is not allowed to source current into VERR ...
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... RAMP PEAK 4 ⋅ --------------------------------------- - – V IN MIN ) ( ) k Ω ISL6742 GND Rs (EQ. 8) – --------- - 1 – 300 (EQ FN9183.1 July 25, 2005 ...
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... OUTBN (SR2) FIGURE 11. BASIC WAVEFORM TIMING A useful feature of the ISL6742 is the ability to vary the phase relationship between the PWM outputs (OUTA,B) and the their complements (OUTAN, BN) by ±300ns. This feature allows the designer to compensate for differences in the signal propagation delays between the PWM FETs and the SR FETs ...
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... D – where Vn is the change in the current feedback signal during the on time and Ve is the voltage that must be added by the external ramp. 14 ISL6742 Vn can be solved for in terms of input voltage, current transducer components, and output inductance yielding ⋅ ⋅ ...
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... CT and will reduce the oscillator (EQ. 23) frequency. Parallel Operation Parallel operation of converters using the ISL6742 may be accomplished using the average current signal, IOUT. IOUT (EQ. 24) provides a very accurate representation of the output current and may be used for active current sharing with many sharing techniques commonly used including master-slave and average current sharing methods ...
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... R6 and the output voltage feedback divider. Typically the maximum allowed output voltage increase is limited to a few percent, but must be greater than 16 ISL6742 the tolerance of the feedback and reference components and any distribution drops between units. If remote sensing is used, the adjustment range must also include the difference in distribution drops between the power supply outputs and the remote sensing location ...
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... An overcurrent condition is not considered a fault and does not result in a shutdown. 17 ISL6742 Thermal Protection Internal die over temperature protection is provided. An integrated temperature sensor protects the device should the junction temperature exceed 140°C. There is approximately 15° ...
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... However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 18 ISL6742 M16.15A 16 LEAD SHRINK SMALL OUTLINE PLASTIC PACKAGE (0.150” WIDE BODY) ...