LTC1699

LTC1699 Series SMBus VID Voltage Programmers U U FEATURES s Fully Compliant with Intel 5-Bit Mobile (LTC1699-80) and Desktop VRM8.4 (LTC1699-81) and VRM9.0 (LTC1699-82) VID Specifications s Precision ±0.35% Programmable Resistor Divider for Use with 0.8V Referenced DC/DC Converters s Two Different Divider Settings Can Be Stored Using a 2-Wire SMBus Serial Interface (Rev 1.1) s Built-In Safeguards Minimize Misprogramming Due to Bus Conflicts s 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 s PGOOD Pin and 50µs PGOOD Timer s Available in MSOP-8 and SSOP-16 Package U APPLICATIO S s Intel Desktop Pentium® III Power Supply s Intel Mobile Pentium® Power Supply with Intel SpeedStepTM Technology s Desktop AMD AthlonTM Power Supply s Software Programmable Remote Power Supply s Power Supplies with Voltage Margining DESCRIPTIO The LTC®1699-80, 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 registe...