Features

• 6-Bit Parallel VID (Voltage Identification) Inputs Set Output Voltage from 0.6V to 1.23V in 10mV Steps
• Output Voltage Range: 0.6V to 5V (Without VID)
• Ultra Low Value DCR/R_SENSE Current Sensing
• ±1% Maximum Total Regulation Voltage Accuracy Over Temperature
• Dual Differential Remote Sensing Amplifiers
• t_ON(MIN) = 40ns, Capable of Very Low Duty Cycles at High Frequency
• Phase-Lockable Frequency from 250kHz to 1MHz
• Current Mismatch Between Channels: 5% Max
• Adjustable Soft-Start Current Ramping or Tracking
• Multi-IC Operation Up To 12 Phases
• Wide V_IN Range: 4.5V to 38V
• Dual Power Good Output Voltage Monitors
• Output Overvoltage Protection
• Foldback Output Current Limiting and Soft Recovery

Typical Application

Description

The LTC®3877 is a VID-programmable, constant frequency current mode step-down controller using an advanced and proprietary architecture. This new architecture enhances the signal-to-noise ratio of the current sense signal, allowing the use of very low DC resistance power inductors to maximize efficiency in high current applications. This feature also dramatically reduces the current sensing error, so that current sharing is greatly improved in multi-phase low DCR applications. In addition, the controller achieves a minimum on-time of just 40ns, permitting the use of high switching frequency at high step-down ratios.

The LTC3877 features dual high speed remote sense differential amplifiers, programmable current sense limits and DCR temperature compensation to limit the maximum output current precisely over temperature. The LTC3877 also features a precise 0.6V reference with guaranteed accuracy of ±0.5%. The LTC3877 is available in a low profile 44-lead 7mm × 7mm QFN package.