Analog Devices Inc. LTC3633AIFE-1#TRPBF

Overview

LTC3633AIFE-1#TRPBF from Analog Devices (formerly Linear Technology) is a dual-channel monolithic synchronous step-down regulator delivering 3A per channel across a 3.6V–20V input range. It features current-mode control, selectable 0°/180° phase shift between channels, adjustable switching frequency (500kHz–4MHz), and supports both Burst Mode® and forced continuous operation. It is used in point-of-load power supplies for FPGA, ASIC, and DSP core voltage regulation.

For engineers reviewing the LTC3633AIFE-1#TRPBF datasheet, LTC3633AIFE-1#TRPBF pinout, LTC3633AIFE-1#TRPBF application, or LTC3633AIFE-1#TRPBF equivalent, key selection criteria include its 1.5V–12V VON sense range (distinguishing it from LTC3633A), dual-channel interleaved operation for reduced input ripple, integrated 3.3V INTVCC and 2.5V V2P5 regulators, and TSSOP-28 package with exposed PGND pad for thermal management.

Technical Context

The LTC3633AIFE-1#TRPBF implements a controlled on-time, current-mode architecture with an internal phase-locked loop that locks switching frequency to either an internal oscillator (set by RT resistor) or external clock applied to MODE/SYNC. Its dual-channel design supports out-of-phase operation via PHMODE pin to reduce RMS input current and relax input capacitor requirements.

Each channel independently regulates output using a 0.6V reference and error amplifier driving ITH compensation node. The LTC3633AIFE-1#TRPBF variant uses VON1/VON2 pins with 1.5V–12V sensing range-enabling stable regulation at higher output voltages than the base LTC3633A-and includes overvoltage lockout (22.5V trip), overtemperature protection, and open-drain PGOOD status outputs with 40µs filtering.

Key Specifications

Pinout & Package

Package: 28-Lead Plastic TSSOP with exposed PGND pad (Pin 29), rated for –40°C to +125°C junction temperature (θ_JA = 30°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3633AEFE#TRPBF, the LTC3633AIFE-1#TRPBF supports higher output voltages natively, eliminating external resistive dividers for 5V/12V rails; versus MP2491DS-LF-Z, it integrates dual channels, auxiliary regulators, and advanced sequencing features - reducing BOM count and improving system reliability in space-constrained designs.

Availability

LTC3633AIFE-1#TRPBF is available at Aetrix Electronics and suitable for industrial PLCs, test equipment, edge networking devices, and medical sensor modules requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LTC3633AIFE-1#TRPBF 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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC3633A family was designed for high-density, high-efficiency dual-rail point-of-load conversion in space- and thermal-constrained systems - emphasizing integration, protection, and flexible sequencing for FPGA, ASIC, and DSP power domains.

FAQ

What is the VON sense range of the LTC3633AIFE-1#TRPBF, and why does it matter?

The LTC3633AIFE-1#TRPBF has a VON sense range of 1.5V to 12V, which directly determines the supported output voltage range without external scaling. This distinguishes it from the base LTC3633A (0.6V–6V) and enables native regulation of common rails like 5V and 12V - simplifying design, improving accuracy, and avoiding errors introduced by external resistor networks. The LTC3633AIFE-1#TRPBF uses this range to maintain controlled on-time operation across its full output span.

How does the LTC3633AIFE-1#TRPBF achieve low EMI in dense PCB layouts?

The LTC3633AIFE-1#TRPBF reduces EMI through 180° interleaved switching (enabled via PHMODE pin), which halves input ripple current and spreads spectral energy. Combined with its constant-frequency current-mode architecture and integrated soft-start/tracking, it minimizes peak currents and transient spikes. Layout best practices - including tight PGND connection to the exposed pad and minimized SW loop area - further suppress radiated emissions. The LTC3633AIFE-1#TRPBF's TSSOP-28 package also supports controlled impedance routing.

Can the LTC3633AIFE-1#TRPBF operate from a single input source while powering two independent output rails?

Yes - the LTC3633AIFE-1#TRPBF supports independent VIN1 and VIN2 inputs, but they may be tied together to a common source (e.g., 12V bus). Each channel regulates its own output (e.g., 3.3V and 5V) with full control over enable (RUN1/RUN2), soft-start (TRACKSS1/TRACKSS2), and feedback (VFB1/VFB2). The LTC3633AIFE-1#TRPBF maintains channel isolation even with shared input, enabling flexible power tree design without cross-talk or load interaction.

What protection features are built into the LTC3633AIFE-1#TRPBF?

The LTC3633AIFE-1#TRPBF includes short-circuit protection on both channels, input overvoltage lockout (trip at 22.5V, resume at 21.5V), overtemperature shutdown, and filtered open-drain PGOOD outputs with ±8% fault detection and ±5% release thresholds. These features operate autonomously without external components. The LTC3633AIFE-1#TRPBF also incorporates anti-shoot-through logic and valley current limiting (2.6A–4.5A) to safeguard internal MOSFETs during fault conditions.

Is the LTC3633AIFE-1#TRPBF pin-compatible with other variants in the LTC3633A family?

Yes - the LTC3633AIFE-1#TRPBF shares identical pinout and footprint with all TSSOP-28 variants in the LTC3633A family, including LTC3633AEFE#TRPBF and LTC3633AIFE#TRPBF. This allows drop-in replacement for design revisions targeting different VON ranges or SVIN capabilities. However, functional differences (e.g., VON range, presence of SVIN) require verification of external circuit compatibility before substitution. The LTC3633AIFE-1#TRPBF retains full electrical and thermal interoperability within the package form factor.