Analog Devices Inc. LTC3370IUH#PBF

Overview

LTC3370IUH#PBF from Analog Devices (formerly Linear Technology) is a configurable 4-channel synchronous buck DC/DC power supply IC integrating eight 1A power stages. 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 a default 2MHz switching frequency with ±10% tolerance. It enables autonomous power-up sequencing in automotive infotainment and industrial FPGA power systems.

For engineers reviewing the LTC3370IUH#PBF datasheet, LTC3370IUH#PBF pinout, LTC3370IUH#PBF application, or LTC3370IUH#PBF equivalent, key selection criteria include its 8-stage configurability (1A–4A per channel), precision enable thresholds (±30mV), PGOODALL fault reporting, die temperature monitoring (220mV @ 25°C, +7mV/°C), and 32-lead 5mm × 5mm QFN package with exposed thermal pad.

Technical Context

The LTC3370IUH#PBF implements a shared-power-stage architecture where eight independent 1A synchronous buck regulators are grouped into four output channels via C1–C3 configuration pins. Each channel draws from a dedicated VIN rail (VINA–VINH), enabling true input isolation across domains.

Its control logic supports dual operating modes: Burst Mode® for ultra-low-noise light-load efficiency (63µA for one active channel) or forced continuous conduction mode via PLL/MODE pin. Switching phases are staggered by 90° to reduce input ripple, and PGOODALL asserts low only when all enabled outputs meet regulation thresholds (98% for Buck 1, 95% for Bucks 2–4).

Key Specifications

Pinout & Package

The LTC3370IUH#PBF is housed in a thermally enhanced 32-lead 5mm × 5mm plastic QFN package with exposed GND pad (Pin 33), requiring soldering to PCB for thermal and electrical integrity. θ_JA = 34°C/W, θ_JC = 3°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel buck regulator applications.

Compared with TPS65218D0RSLR and ISL91211AIRZ-T, the LTC3370IUH#PBF uniquely combines hardware-configurable current staging, eight independent VIN inputs, integrated die temperature sensing, and zero-current shutdown - making it optimal for rugged, autonomous, thermally constrained embedded systems where layout simplicity and thermal intelligence are critical.

Availability

LTC3370IUH#PBF is available at Aetrix Electronics and suitable for automotive ADAS, industrial PLCs, FPGA power delivery, and medical imaging systems requiring stable component supply, extended temperature operation (–40°C to 125°C), and long-term obsolescence management.

Supply support for LTC3370IUH#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 LTC3370IUH#PBF belongs to Linear's configurable multichannel buck regulator family, designed specifically for space-constrained, thermally demanding applications requiring flexible, isolated, and autonomous power delivery without microcontroller dependency.

FAQ

What is the operating temperature range for the LTC3370IUH#PBF?

The LTC3370IUH#PBF is rated for –40°C to 125°C junction temperature and is qualified for industrial and automotive applications. Its overtemperature protection activates at 170°C with 10°C hysteresis, and the exposed thermal pad (Pin 33) must be soldered to PCB copper for effective heat dissipation. This grade (I) guarantees full electrical specifications across the entire –40°C to 125°C range.

How do I configure the LTC3370IUH#PBF for a 3-output design with currents of 2A, 3A, and 3A?

To configure the LTC3370IUH#PBF for 2A/3A/3A outputs, set C1=LOW, C2=HIGH, C3=LOW per Table 1 in the datasheet. This assigns two 1A stages to Buck 1 (2A), three to Buck 2 (3A), and three to Buck 3 (3A), leaving Buck 4 disabled. Ensure FB4 and EN4 are grounded, and route appropriate inductors and feedback dividers for each active output. The LTC3370IUH#PBF supports exactly this 2+3+3 configuration out-of-the-box.

Does the LTC3370IUH#PBF support synchronization to an external clock?

Yes, the LTC3370IUH#PBF supports external clock synchronization via the PLL/MODE pin (Pin 28). When driven with a clean CMOS clock signal (1MHz–3MHz, t_LOW/t_HIGH > 40ns), all internal switches lock to the external frequency and operate in forced continuous conduction mode. Slope compensation automatically adapts to the applied clock frequency, preserving stability across the full range.

What is the purpose of the PGOODALL pin on the LTC3370IUH#PBF?

The PGOODALL pin (Pin 14) is an open-drain output that signals global power-good status. It pulls low if *any* enabled buck regulator's output falls below its respective PGOOD threshold (98% of setpoint for Buck 1, 95% for Bucks 2–4) or if all bucks are disabled. This single-pin fault indicator simplifies system-level power sequencing and monitoring without requiring individual PGOOD lines for each channel - a key feature of the LTC3370IUH#PBF.

Can the LTC3370IUH#PBF operate with different input voltages on each VIN pin?

Yes, the LTC3370IUH#PBF is explicitly designed for independent input supplies: VINA–VINH accept 2.25V to 5.5V each, and may be sourced from different rails (e.g., VINA = 3.3V, VINB = 5V, VINC = 2.5V). This isolation prevents cross-regulation and enables mixed-domain power architectures - a defining capability of the LTC3370IUH#PBF not found in most quad-buck PMICs.