Features

• Sub-Milliohm DCR Current Sensing
• Operates with Power Blocks, DRMOS or External Gate Drivers and MOSFETs
• Supports Phase Shedding and N+1 Phase Redundancy
• Programmable DCR Temperature Compensation
• ±0.75% Maximum Total DC Output Error Over Temperature
• Dual Differential Remote Output Voltage Sense Amplifiers
• Phase-Lockable Fixed Frequency Range: 200kHz to 1.2MHz
• V_IN Range: 4.5V to 38V
• V_OUT Range: 0.6V to 3.5V
• Supports Smooth Start-Up into Pre-Biased Outputs
• Programmable Soft-Start or V_OUT Tracking
• Hiccup Mode/Soft Recovery from Output Overcurrent
• 36-Lead (5mm × 6mm) QFN Package

Typical Application

Description

The LTC®3774 is a dual PolyPhase® current mode synchronous step-down switching regulator controller that drives power blocks, DRMOS or external gate drivers and power MOSFETs. It offers an LTC-proprietary technique that enhances the signal-to-noise ratio of the current sense signal, allowing the use of inductors with very low DC winding resistances as the current sense element for maximum efficiency and reduced jitter.

The maximum current sense voltage is programmable from 10mV to 30mV. High speed, low offset remote sense differential amplifiers and a precise 0.6V reference provide accurate output voltages between 0.6V and 3.5V from a wide 4.5V to 38V input supply range. Soft recovery from output shorts or overcurrent minimizes output overshoot. Burst Mode® operation, continuous and pulse-skipping modes are supported. The constant operating frequency can be synchronized to an external clock or linearly programmed from 200kHz to 1.2MHz. Up to six LTC3774 controllers can be paralleled for 1-, 2-, 3-, 4-, 6-, 8- or 12-phase operation.

The LTC3774 is available in a 36-lead (5mm × 6mm) QFN package.