ISL85005A: 4.5V to 18V Input, 5A High Efficiency Synchronous Buck Regulator

The ISL85005 and ISL85005A are monolithic, synchronous buck regulators with integrated 5A, 18V high-side and low-side FETs. These devices also provide an integrated bootstrap diode for the high-side gate driver to reduce the external parts count. These devices have a wide input voltage range to support applications with input voltage from multi-cell batteries or regulated 5V and 12V power rails.

The ISL85005 and ISL85005A regulate the output voltage with current mode control and have an internal oscillator. The switching frequency of the ISL85005 is internally set as 500kHz, and can be synchronized to an external clock signal with frequency ranges from 300kHz to 2MHz. The ISL85005A has a fixed 500kHz switching frequency.

The ISL85005 has a fixed 2.3ms soft-start, while the ISL85005A features programmable soft-start to limit inrush current during startup. With SS pin floating, the soft-start time of ISL85005A is also 2.3ms.

The ISL85005 can be configured in either forced Continuous Conduction Mode (CCM) or Diode Emulation Mode (DEM). DEM enables high efficiency at light-load conditions. The ISL85005A always operates in forced CCM.

The ISL85005 and ISL85005A have built-in protections including input UVLO protection, input and output overvoltage protection, high-side cycle-by-cycle current limit, low-side forward current limit and reverse current limit, and thermal shutdown.

Key Differences in Family
Part NumberInternal/External CompensationExternal Frequency SyncProgrammable Soft-startSwitching FrequencyCurrent RatingDatasheet
ISL85003YesYesNo500kHz3Aisl85003-a.pdf
ISL85003AYesNoYes500kHz3Aisl85003-a.pdf
ISL85005YesYesNo500kHz5Aisl85005-05a.pdf
ISL85005AYesNoYes500kHz5Aisl85005-05a.pdf
Key Features
  • 4.5V to 18V input voltage range
  • Internal 5A, 18V high-side and low-side MOSFET switches
  • ±1%, 0.8V feedback voltage reference
  • Integrated bootstrap diode with undervoltage detection
  • Current mode control with internal slope compensation
  • Internal or external compensation options
  • Default internally set 500kHz switching frequency
  • Synchronization capability to external clock (ISL85005)
  • Diode Emulation Mode (DEM) and forced CCM (FCCM) options (ISL85005)
  • Adjustable soft-start time (ISL85005A)
  • Output Power-Good (PG) indicator
  • Input undervoltage lockout (UVLO), input and output overvoltage protection
  • High-side cycle-by-cycle current limit, low-side forward and reverse overcurrent protection, and thermal shutdown
  • Small 12-pin 3mmx4mm Dual Flat No-Lead (DFN) package with EPAD for enhanced thermal performance
Applications
  • Network and communication equipments
  • Battery powered systems
  • Multifunction printers
  • Point-of-load regulators
  • Standard 12V rail supplies
  • Embedded computing systems
Typical Diagram
Application Notes
TitleTypeUpdatedSizeOther Languages
AN9208: High Frequency Power ConvertersPDF13 Nov 201478 KB
AN9210: A New PSpice Subcircuit for the Power MOSFET Featuring Global Temperature OptionsPDF13 Nov 2014190 KB
AN9209: A Spice-2 Subcircuit Representation for Power MOSFETs Using Empirical MethodsPDF13 Nov 201456 KB
AN7244: Understanding Power MOSFETsPDF13 Nov 201441 KB
Datasheets
TitleTypeUpdatedSizeOther Languages
ISL85005, ISL85005A DatasheetPDF20 Mar 20172.06 MB
Design Files
TitleTypeUpdatedSizeOther Languages
ISL85005AEVAL1Z Design FilesZIP29 Mar 2017629 KB
ISL85005ADEMO1Z Design FilesZIP04 Mar 2017847 KB
User Guides
TitleTypeUpdatedSizeOther Languages
ISL85005xDEMO1Z User GuidePDF20 Mar 2017719 KB
ISL85005EVAL1Z, ISL85005AEVAL1Z User GuidePDF20 Mar 20171.05 MB
White Papers
TitleTypeUpdatedSizeOther Languages
How to Protect Buck Regulators from Overcurrent DamagePDF30 Mar 2017392 KB
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
ISL85005AFRZ12 Ld DFN0.022123260RoHS
ISL85005AFRZ-TK12 Ld DFN T+R0.022123260RoHS
ISL85005AFRZ-T7A12 Ld DFN T+R0.022123260RoHS
ISL85005AFRZ-T12 Ld DFN T+R0.022123260RoHS
ISL85005AEVAL1ZN/ARoHS
ISL85005ADEMO1ZN/ARoHS
ISL85005, ISL85005A Datasheet 20 Mar 2017
AN9208: High Frequency Power Converters 13 Nov 2014
AN9210: A New PSpice Subcircuit for the Power MOSFET Featuring Global Temperature Options 13 Nov 2014
AN9209: A Spice-2 Subcircuit Representation for Power MOSFETs Using Empirical Methods 13 Nov 2014
AN7244: Understanding Power MOSFETs 13 Nov 2014
ISL85005AEVAL1Z Design Files 29 Mar 2017
ISL85005ADEMO1Z Design Files 04 Mar 2017
ISL85005xDEMO1Z User Guide 20 Mar 2017
ISL85005EVAL1Z, ISL85005AEVAL1Z User Guide 20 Mar 2017
How to Protect Buck Regulators from Overcurrent Damage 30 Mar 2017
Five Easy Steps to Create a Multi-Load Power Solution 30 Jan 2017