Features

• True Current Mode with Ultrafast Transient Response
• Stable with Ceramic C_OUT
• t_ON(MIN) < 100ns for Operation from High Input Ranges
• Supports Active Voltage Positioning
• No Sense Resistor Required
• 5-Bit VID Programmable Output Voltage: 0.6V to 1.75V
• Dual N-Channel MOSFET Synchronous Drive
• Programmable Output Offsets
• Power Good Output Voltage Monitor
• Wide V_IN Range: 4V to 36V
• ±1% 0.6V Reference
• Adjustable Frequency
• Programmable Soft-Start
• Output Overvoltage Protection
• Optional Short-Circuit Shutdown Timer
• Forced Continuous Control Pin
• Logic Controlled Micropower Shutdown: I_Q ≤ 30μA
• Available in 0.209" Wide 28-Lead SSOP Package

Typical Application

Description

The LTC®3714 is a synchronous step-down switching regulator controller for CPU power. An output voltage between 0.6V and 1.75V is selected by a 5-bit code (Intel mobile VID specification). The controller uses a constant on-time, valley current control architecture to deliver very low duty cycles without requiring a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in V_IN and V_OUT.

Discontinuous mode operation provides high efficiency operation at light loads. A forced continuous control pin reduces noise and RF interference and can assist secondary winding regulation by disabling discontinuous mode when the main output is lightly loaded. Internal op amp allows programmable offsets to the output voltage during power saving modes.

Fault protection is provided by internal foldback current limiting, an output overvoltage comparator and optional short-circuit shutdown timer. Soft-start capability for supply sequencing is accomplished using an external timing capacitor. The regulator current limit level is user programmable. Wide supply range allows operation from 4V to 36V at the input.