Analog Devices Inc. LTC3371IUHF#PBF

Overview

LTC3371IUHF#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 LTC3371IUHF#PBF datasheet, LTC3371IUHF#PBF pinout, LTC3371IUHF#PBF application, or LTC3371IUHF#PBF equivalent, key selection criteria include its 8-stage configurability (1A–4A per channel), CT-programmed watchdog timing, independent RST pins per buck, thermally enhanced 38-lead QFN package, and precision enable thresholds for autonomous power sequencing.

Technical Context

The LTC3371IUHF#PBF implements four synchronous buck regulators sharing eight discrete 1A power stages, assigned to outputs via C1–C3 pin programming. Each buck uses internal PMOS/NMOS switches (R_PMOS = 300 mΩ, R_NMOS = 240 mΩ) and supports Burst Mode® or forced continuous operation.

Its timing architecture centers on the CT pin: a single capacitor sets delays for all four RST pins, WDO assertion, and watchdog timeout windows. The RT pin enables resistor-programmable oscillator frequency (1–3 MHz) or PLL synchronization, while phased 90° switching reduces input ripple.

Key Specifications

Pinout & Package

The LTC3371IUHF#PBF is housed in a thermally enhanced 38-lead 5mm × 7mm QFN package with exposed pad (Pin 39 = GND). Pin assignment is identical for QFN (UHF) and TSSOP (FE) packages per datasheet Figure 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS65218D0RSLR and ISL91211AIRZ-T7A, the LTC3371IUHF#PBF uniquely offers pin-strapped stage reconfiguration, eight independent VIN supplies, and a single-capacitor watchdog/RST timing architecture - making it optimal for industrial and automotive systems demanding hardware-defined reliability and flexibility without software overhead.

Availability

LTC3371IUHF#PBF is available at Aetrix Electronics and suitable for automotive ADAS modules, industrial PLCs, medical imaging devices, and telecom remote radio units requiring stable component supply, extended temperature operation, and long-term lifecycle support.

Supply support for LTC3371IUHF#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. Linear's legacy emphasizes precision, ruggedness, and innovation in analog and power ICs.

The LTC3371IUHF#PBF belongs to Linear's configurable multi-output buck regulator family, designed specifically for systems needing flexible, hardware-programmable power delivery with integrated fault monitoring and sequencing - targeting automotive, industrial, and medical applications where software-free reliability is essential.

FAQ

What is the maximum output current per channel supported by the LTC3371IUHF#PBF?

The LTC3371IUHF#PBF supports up to 4A per output channel by combining four of its eight 1A power stages. Configuration is set via C1–C3 pins, enabling eight distinct current allocations (e.g., 4×1A, 2×2A, 1×3A+1×1A, or 1×4A). The actual current per channel depends on thermal design and input/output conditions, with full 4A capability validated at 125°C junction temperature in the 5mm × 7mm QFN package.

How does the CT pin configure both watchdog timing and RST assertion delay in the LTC3371IUHF#PBF?

The CT pin on the LTC3371IUHF#PBF accepts a single external capacitor (e.g., 10nF) that sets the timebase for all timing-critical functions: WDI timeout (1.62s), WDO low pulse width (202ms), and RST1–RST4 assertion delay (160–240ms). This unified timing architecture eliminates discrete RC networks, ensures matched delays across all monitored rails, and simplifies layout - a key differentiator versus multi-capacitor watchdog ICs.

Can the LTC3371IUHF#PBF operate with different input voltages on each of its eight VIN pins?

Yes, the LTC3371IUHF#PBF features eight independent VIN pins (VINA–VINH), each rated for 2.25V to 5.5V. This allows connection to separate power domains - for example, VINA/VINB from a 3.3V system rail, VINC/VIND from a 5V auxiliary supply, and VINE–VINH from a battery-backed 2.5V source. Each pair feeds dedicated power stages, enabling true mixed-input multi-rail generation without level-shifting or cross-regulation issues.

What is the purpose of the C1, C2, and C3 pins on the LTC3371IUHF#PBF?

The C1, C2, and C3 pins on the LTC3371IUHF#PBF are hardware configuration inputs that select one of eight possible power-stage allocations across its four buck outputs. Tied to VCC or GND, they form a 3-bit code (e.g., 000 = four 2A outputs; 111 = one 4A output) - enabling flexible current distribution without firmware or I²C. This pin-strapped approach ensures deterministic, boot-time configuration immune to software faults or bus errors.

Does the LTC3371IUHF#PBF include thermal monitoring, and how is it implemented?

Yes, the LTC3371IUHF#PBF includes an on-die temperature sensor accessible via the TEMP pin. Its output is ratiometric: 220mV at 25°C with a slope of 7mV/°C (range 180–260mV at 25°C). This analog voltage can be read by an external ADC to monitor junction temperature in real time. Combined with 170°C overtemperature shutdown and 10°C hysteresis, it provides dual-layer thermal protection - both proactive monitoring and automatic fault response - critical for automotive and industrial deployments.