Analog Devices Inc. LTC3727IG-1#PBF

Overview

LTC3727IG-1#PBF from Analog Devices (formerly Linear Technology) is a dual-phase, synchronous step-down switching regulator controller driving two independent N-channel MOSFET stages. It operates over 4V–36V input, delivers 0.8V–14V output with ±1% accuracy, supports out-of-phase 250kHz–550kHz operation to reduce input ripple, and features OPTI-LOOP® compensation, power good monitoring, and 99% duty cycle dropout capability - used in telecom power supplies requiring high-efficiency dual-rail generation.

For engineers reviewing the LTC3727IG-1#PBF datasheet, LTC3727IG-1#PBF pinout, LTC3727IG-1#PBF application, or LTC3727IG-1#PBF equivalent, key selection criteria include phase-lockable frequency range, dual-channel current-mode control architecture, soft-start current ramping, foldback current limiting, and thermal performance in SSOP-28 package at –40°C to +85°C.

Technical Context

The LTC3727IG-1#PBF implements a constant-frequency current-mode control architecture with two independent 180° out-of-phase channels, minimizing RMS input current and EMI. Each channel uses a transconductance error amplifier (gm = 1.3 mmho, GBW = 3 MHz) and precision 0.8V reference for feedback regulation.

It integrates dual gate drivers (TG/BG) with 50–90 ns transition times, a 7.5V internal LDO (INTVCC), 3.3V linear regulator (±1% line/load regulation), and protection circuitry including output overvoltage lockout (0.84–0.88V), undervoltage lockout (3.5–4V), and latchoff-enabled short-circuit shutdown (LTC3727 variant only).

Key Specifications

Pinout & Package

Package: 28-lead plastic SSOP (G package), RoHS-compliant, exposed pad not present - optimized for thermal dissipation in compact PCB layouts with θ_JA = 95°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-phase synchronous buck controller applications.

Compared with LTC3727EG-1#PBF, the LTC3727IG-1#PBF guarantees full –40°C to +85°C performance; compared with MP8765GL-Z, it offers higher input voltage tolerance, external FET control, and phase synchronization - critical for high-reliability, thermally demanding, or EMI-sensitive applications.

Availability

LTC3727IG-1#PBF is available at Aetrix Electronics and suitable for telecom power supplies, automotive infotainment systems, and industrial PLC I/O modules requiring stable component supply with guaranteed extended temperature performance.

Supply support for LTC3727IG-1#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices acquired Linear Technology in 2017 and maintains its legacy high-performance power management portfolio with rigorous qualification and long-term support.

The LTC3727 family targets high-efficiency, multi-rail DC/DC conversion in space- and thermal-constrained systems where interleaved dual-phase operation improves input filtering, EMI, and efficiency - especially in telecom, automotive, and industrial applications.

FAQ

What is the operating temperature range guaranteed for the LTC3727IG-1#PBF?

The LTC3727IG-1#PBF is fully specified and guaranteed over the industrial temperature range of –40°C to +85°C. Unlike the E-grade variants, this I-grade part undergoes extended characterization and screening to ensure all electrical parameters-including output accuracy, current sense threshold, and oscillator frequency-remain within datasheet limits across this full range.

Does the LTC3727IG-1#PBF support phase synchronization to an external clock?

Yes, the LTC3727IG-1#PBF supports external synchronization via the PLLIN pin. When an external clock signal is applied, the internal phase-locked loop aligns the rising edge of the top gate drive (TG1) to that signal's rising edge. This eliminates beat frequencies and simplifies EMI compliance in systems with multiple synchronized switching regulators.

How does the LTC3727IG-1#PBF implement short-circuit protection?

The LTC3727IG-1#PBF provides foldback current limiting that activates when VOSENSE falls below 70% of nominal output. It does not include latchoff shutdown-the LTC3727 (non-"-1") variant has that feature. During overload, the controller reduces current limit progressively, minimizing MOSFET heating while maintaining regulated output until the fault clears.

Can the LTC3727IG-1#PBF drive both high-side and low-side N-channel MOSFETs?

Yes, the LTC3727IG-1#PBF integrates dual high-current gate drivers: TG1/TG2 for top-side N-MOSFETs (floating, bootstrap-biased) and BG1/BG2 for bottom-side N-MOSFETs (ground-referenced). Each driver delivers ≥3A peak current with 40–90 ns transition times, supporting efficient synchronous rectification without external drivers.

What is the purpose of the FCB pin on the LTC3727IG-1#PBF?

The FCB (Forced Continuous Bias) pin on the LTC3727IG-1#PBF serves two functions: (1) pulling it below 0.8V forces continuous conduction mode on both channels, useful for regulating secondary windings; (2) setting it between 0.8V and (INTVCC – 2V) enables Burst Mode® operation for improved light-load efficiency - selectable per design requirements.