ISL6545: 5V or 12V Single Synchronous Buck Pulse-Width Modulation (PWM) Controller

The ISL6545, ISL6545A makes simple work out of implementing a complete control and protection scheme for a DC/DC stepdown converter driving N-Channel MOSFETs in a synchronous buck topology. Since it can work with either 5V or 12V supplies, this one IC can be used in a wide variety of applications within a system. The ISL6545, ISL6545A (hereafter referred to as "ISL6545x", except as needed) integrates the control, gate drivers, output adjustment, monitoring and protection functions into a single 8 Ld SOIC or 10 Ld DFN package.

The ISL6545x provides single feedback loop, voltage-mode control with fast transient response. The output voltage can be precisely regulated to as low as 0.6V, with a maximum tolerance of ±1.0% over-temperature and line voltage variations. A selectable fixed frequency oscillator (ISL6545 for 300kHz; ISL6545A for 600kHz) reduces design complexity, while balancing typical application cost and efficiency.

The error amplifier features a 20MHz gain-bandwidth product and 9V/µs slew rate which enables high converter bandwidth for fast transient performance. The resulting PWM duty cycles range from 0% to 100%.

Protection from overcurrent conditions is provided by monitoring the rDS(ON) of the lower MOSFET to inhibit PWM operation appropriately. This approach simplifies the implementation and improves efficiency by eliminating the need for a current sense resistor.

Key Features
  • Operates from +5V or +12V Supply Voltage (for bias)
    • 1.0V to 12V VIN Input Range (up to 20V possible with restrictions; see Input Voltage Considerations)
    • 0.6V to VIN Output Range
    • Integrated Gate Drivers use VCC (5V to 12V)
    • 0.6V Internal Reference; ±1.0% tolerance
  • Simple Single-Loop Control Design
    • Voltage-Mode PWM Control
    • Drives N-Channel MOSFETs
    • Traditional Dual Edge Modulator
  • Fast Transient Response
    • High-Bandwidth Error Amplifier
    • Full 0% to 100% Duty Cycle
  • Lossless, Programmable Overcurrent Protection
    • Uses Lower MOSFET's rDS(ON)
  • Small Converter Size in 8 Ld SOIC or 10 Ld DFN
    • 300kHz or 600kHz Fixed Frequency Oscillator
    • Fixed Internal Soft-Start, Capable into a Pre-biased Load
    • Integrated Boot Diode
    • Enable/Shutdown Function on COMP/SD Pin
    • Output Current Sourcing and Sinking
  • Pb-Free (RoHS Compliant)
Applications
  • Power Supplies for Microprocessors or Peripherals
    • PCs, Embedded Controllers, Memory Supplies
    • DSP and Core Communications Processor Supplies
  • Subsystem Power Supplies
    • PCI, AGP; Graphics Cards; Digital TV
    • SSTL-2 and DDR/DDR2/DDR3 SDRAM Bus Termination Supply
  • Cable Modems, Set Top Boxes, and DSL Modems
  • Industrial Power Supplies; General Purpose Supplies
  • 5V or 12V-Input DC/DC Regulators
  • Low-Voltage Distributed Power Supplies
Typical Diagram
Application Notes
TitleTypeUpdatedSizeOther Languages
AN1243: Getting Started with iSim and iSim:PEPDF28 Aug 2015228 KB
AN1652: iSim:PE Users GuidePDF13 Nov 20141.45 MB
Datasheets
TitleTypeUpdatedSizeOther Languages
ISL6545, ISL6545A DatasheetPDF07 Oct 2015432 KB
White Papers
TitleTypeUpdatedSizeOther Languages
Five Easy Steps to Create a Multi-Load Power SolutionPDF30 Jan 2017502 KB
Order Information
Part NumberPackage TypeWeight(g)PinsMSL RatingPeak Temp (°C)RoHS Status
ISL6545CBZ8 Ld SOIC0.07683260RoHS
ISL6545CBZ-T8 Ld SOIC T+R0.07683260RoHS
ISL6545CRZ10 Ld DFN0.022103260RoHS
ISL6545CRZ-T10 Ld DFN T+R0.022103260RoHS
ISL6545IBZ8 Ld SOIC0.07683260RoHS
ISL6545IBZ-T8 Ld SOIC T+R0.07683260RoHS
ISL6545IRZ10 Ld DFN0.022103260RoHS
ISL6545IRZ-T10 Ld DFN T+R0.022103260RoHS
ISL6545EVAL1N/A
Datasheet
ISL6545, ISL6545A Datasheet ISL6545
ISL6545, ISL6545A Datasheet 07 Oct 2015
Other
AN1243: Getting Started with iSim and iSim:PE 28 Aug 2015
AN1652: iSim:PE Users Guide 13 Nov 2014
10 Ld DFN ISL9000AM
8 Ld SOIC T+R ISL84514
Five Easy Steps to Create a Multi-Load Power Solution 30 Jan 2017