Features and Benefits

  • Fully Compliant with Intel 5-Bit Mobile (LTC1699-80) and Desktop VRM8.4 (LTC1699-81) and VRM9.0 (LTC1699-82) VID Specification
  • Precision ±0.35% Programmable Resistor Divider for Use with 0.8V Referenced DC/DC Converters
  • Two Different Divider Settings Can Be Stored Using a 2-Wire SMBus Serial Interface (Rev 1.1)
  • Built-In Safeguards Minimize Misprogramming Due to Bus Conflicts
  • Three Open-Drain Pins (CPU_ON, IO_ON, CLK_ON) and a Global Control Pin (VRON) to Shutdown or Soft-Start 3 DC/DC Converters Simultaneously
  • PGOOD Pin and 50µs PGOOD Timer
  • Available in MSOP-8 and SSOP-16 Package

Product Details

The LTC1699-80, LTC1699-81 and LTC1699-82 are precision (±0.35% max), digitally programmed resistor dividers that comply with Intel 5-bit mobile (LTC1699-80), desktop VRM8.4 (LTC1699-81) and VRM9.0 (LTC1699-82) VID specifications. Each IC can switch the output of a DC/DC converter between two set voltages. A digital input pin, SEL, selects one of two divider settings stored into registers via a 2-wire SMBus interface.

The SMBus interface uses Write Word protocol to setup the registers and to turn the DC/DC converters on or off. Read Word protocol is used to verify register contents and to return the On/Off status of the converters. The LTC1699-80, LTC1699-81 and LTC1699-82 incorporate safeguards against errors due to bus conflicts.

Three open-drain N-channel outputs (CPU_ON, IO_ON and CLK_ON) are provided to turn DC/DC converter supplies on or off via their RUB/SS inputs. A global control pin, VRON is used to turn the converters on or off simultaneously. An internal timer pulls the PGOOD pin low for 50µs if the divider setting changes or the converters are turned on via the SMBus and the VRON pin.


  • Intel Desktop Pentium® III Power Supply
  • Intel Mobile Pentium® Power Supply with Intel SpeedStep Technology
  • Desktop AMD Athlon Power Supply
  • Software Programmable Remote Power Supply
  • Power Supplies with Voltage Margining

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

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The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

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