Analog Devices Inc. LTC3371IFE#PBF

Overview

LTC3371IFE#PBF from Analog Devices (formerly Linear Technology) is a configurable 4-channel synchronous buck DC/DC power supply IC with integrated 8×1A power stages, watchdog timer, and power-on reset. It supports input voltages from 2.25V to 5.5V per channel, delivers up to 4A per output via programmable stage combining, and operates at 1MHz–3MHz switching frequency. It is used in automotive infotainment and industrial control systems requiring precise multi-rail sequencing and fault monitoring.

For engineers reviewing the LTC3371IFE#PBF datasheet, LTC3371IFE#PBF pinout, LTC3371IFE#PBF application, or LTC3371IFE#PBF equivalent, key selection criteria include its 8-stage configurability (1A–4A per channel), CT-programmed watchdog timing, independent RST pins for per-channel regulation status, and thermally enhanced 38-lead TSSOP package with exposed pad.

Technical Context

The LTC3371IFE#PBF implements four synchronous buck regulators sharing eight discrete 1A power stages, assigned via C1–C3 pin programming into eight possible output configurations (e.g., 1×4A, 2×2A, 4×1A). Each buck channel accepts independent VIN supplies (2.25V–5.5V) and features precision enable thresholds (±20mV) for autonomous sequencing.

Its internal oscillator is programmable via RT resistor (1–3MHz) or synchronizable via PLL/MODE pin; Burst Mode® operation enables ultra-low no-load current (68µA for one active channel). The CT pin sets timing for four independent RST outputs and a windowed watchdog timer, while TEMP pin provides die temperature monitoring with ±2°C accuracy over –40°C to 125°C.

Key Specifications

Pinout & Package

The LTC3371IFE#PBF is housed in a 38-lead plastic TSSOP package with an exposed thermal pad (Pin 39) that must be soldered to PCB ground for thermal performance and electrical stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-channel buck regulator applications.

Compared with LTC3372IFE#PBF, the LTC3371IFE#PBF offers identical power stage flexibility and watchdog functionality at lower cost and complexity, while TPS65270PWP trades configurability and monitoring for reduced bill-of-materials and simpler layout-making it viable only in fixed-rail, non-safety-critical applications.

Availability

LTC3371IFE#PBF is available at Aetrix Electronics and suitable for automotive infotainment, industrial PLC modules, and medical imaging sensor arrays requiring stable component supply across extended temperature ranges (–40°C to 125°C).

Supply support for LTC3371IFE#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 high-performance power management portfolio with rigorous automotive and industrial qualification standards.

The LTC3371IFE#PBF belongs to the LTC® multi-output buck regulator product line, designed specifically for space-constrained systems needing flexible, fault-aware power delivery without external sequencing or supervision circuitry.

FAQ

What is the maximum output current per channel supported by the LTC3371IFE#PBF?

The LTC3371IFE#PBF supports up to 4A per output channel by combining four of its eight integrated 1A synchronous buck power stages. Configuration is set via C1–C3 pins, enabling eight distinct arrangements-including 1×4A, 2×2A, or 4×1A-without changing external components. This scalability allows the same LTC3371IFE#PBF to serve diverse load profiles across product variants.

How does the CT pin affect the watchdog and RST timing in the LTC3371IFE#PBF?

The CT pin on the LTC3371IFE#PBF connects to a capacitor (e.g., 10nF) that sets the timebase for both the windowed watchdog timer and the assertion delay of RST1–RST4 pins. With CT = 10nF, the watchdog timeout period (tWDI) is 1.62s typical, and RST assertion delay is 202ms. Scaling CT linearly adjusts all timing parameters, enabling design-specific fault response windows without firmware changes. This behavior is confirmed in the LTC3371IFE#PBF Electrical Characteristics table.

Can the LTC3371IFE#PBF operate with different input voltages on each VIN pin?

Yes, the LTC3371IFE#PBF supports independent input supplies on VINA through VINH (eight total), each rated for 2.25V to 5.5V. This allows heterogeneous rail sourcing-for example, powering Buck 1 from a 3.3V LDO and Buck 2 from a 5V DC/DC-enabling optimized efficiency and noise isolation per channel. Each VIN must be bypassed with ≥10µF ceramic capacitance to GND, as specified in the LTC3371IFE#PBF Pin Functions section.

What is the thermal performance difference between the QFN and TSSOP packages for the LTC3371IFE#PBF?

The LTC3371IFE#PBF in TSSOP (LTC3371IFE#PBF) has θJA = 25°C/W, versus 34°C/W for the QFN variant (LTC3371EUHF#PBF). This 9°C/W improvement means the TSSOP version dissipates heat more effectively under identical PCB layout and airflow conditions, allowing higher sustained output current or operation in hotter ambient environments. Both packages require soldering the exposed pad (Pin 39) to a thermal plane for optimal performance, as stated in the Absolute Maximum Ratings table.

Does the LTC3371IFE#PBF support forced continuous conduction mode (FCCM) across all channels simultaneously?

Yes, the LTC3371IFE#PBF supports forced continuous conduction mode (FCCM) on all four buck channels simultaneously via the PLL/MODE pin. When PLL/MODE is pulled high (≥VCC – 0.4V), all regulators operate in FCCM regardless of load, eliminating mode transitions and associated output voltage ripple. This is essential for noise-sensitive applications like high-resolution ADCs or RF subsystems, and is explicitly documented in the LTC3371IFE#PBF Operation section under "Buck Switching Regulators."