Features

• 3.6V to 20V Input Voltage Range
• Wide Output Voltage Range of 0.6V to 97% V_IN Optimized for 0.6V to 6V
• Low R_DS(ON) Integrated Switches Provide Up to 95% Efficiency
• Up to 2.5A of Output Current
• Average Input and Output Current Monitoring
• Programmable Average Input/Output Current Limit
• Die Temperature Monitor and Programmable Limit
• Adjustable Switching Frequency: 500kHz to 3MHz
• External Frequency Synchronization
• Current Mode Operation for Excellent Line and Load Transient Response
• 0.6V Reference with 1% Accuracy Over Temperature
• User Selectable Burst Mode® or Forced Continuous Operation
• Short-Circuit Protected
• Output Voltage Tracking Capability
• Power Good Status Output
• Available in Small, Thermally Enhanced, 20-Lead (3mm × 4mm) QFN Package

Typical Application

Description

The LTC®3626 is a high efficiency, monolithic synchronous buck regulator using a phase-lockable controlled on-time, current mode architecture capable of supplying up to 2.5A of output current. The operating supply voltage range is 3.6V to 20V, making it suitable for a wide range of power supply applications.

The operating frequency is programmable from 500kHz to 3MHz with an external resistor allowing the use of small surface mount inductors. For applications sensitive to switching noise, the LTC3626 can be externally synchronized over the same frequency range. An internal phaselocked loop aligns the on-time of the top power MOSFET to the internal or external clock. This unique controlled on-time architecture is ideal for high step-down ratio applications that demand high switching frequencies and fast transient response. An internal phase lock loop servos the on-time of the internal one-shot timer to match the frequency of the internal clock or an applied external clock.

The LTC3626 offers two operational modes: Burst Mode and forced continuous mode to allow the user to optimize output voltage ripple, noise and light load efficiency for a given application.