Analog Devices Inc. LTC2926CUFD#PBF

Overview

LTC2926CUFD#PBF from Analog Devices (formerly Linear Technology) is a precision MOSFET-controlled power supply tracker IC that manages up to three rail sequences-master + two slaves-with adjustable ramp rates, voltage offsets, and time delays. It integrates dual slave gate drivers (SGATE1/SGATE2), master gate drive (MGATE), remote sense switching control (RSGATE), and status/fault I/O. Used in FPGA, microprocessor, and server power sequencing where VCORE/VI/O tracking must avoid latch-up.

For engineers reviewing the LTC2926CUFD#PBF datasheet, LTC2926CUFD#PBF pinout, LTC2926CUFD#PBF application, or LTC2926CUFD#PBF equivalent, key selection criteria include its 20-lead QFN (4mm × 5mm) package, ±3% FB-to-TRACK current matching, 0.8V internal reference, 5.5V gate drive headroom above VCC, and fault-latched disconnect behavior with 1.23V input thresholds and 75mV hysteresis on ON/PGI/PGTMR pins.

Technical Context

The LTC2926CUFD#PBF implements a servo-based tracking architecture: each TRACK pin is held at 0.800V (±24mV over temperature), and its sourced current is mirrored to the corresponding FB pin to regulate slave supply output via external N-channel MOSFET source followers. The master ramp is generated either by MGATE driving an external capacitor (10µA constant current) or by tying MGATE to RAMP.

Its fault management uses a latched state machine triggered by low-voltage assertion on FAULT (≤0.5V), STATUS/PGI (≤1.0V after PGTMR timeout), or undervoltage on VCC (<2.4V). Fault recovery requires ON pin voltage <0.5V to clear the latch. Integrated charge pumps ensure MGATE, SGATE1/2, and RSGATE reach ≥5.0V above VCC for logic-level MOSFET enhancement.

Key Specifications

Pinout & Package

Package: 20-lead plastic QFN (4mm × 5mm), exposed pad (Pin 21) connected to GND. Thermal resistance θJA = 43°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power supply tracking applications.

Compared with LTC2925CUFD#PBF, the LTC2926CUFD#PBF adds third-rail control, fault-latched shutdown, and automatic remote sense switching-enabling robust, field-configurable sequencing in high-reliability systems. Versus TPS652862ARSLR, it trades integration for design flexibility: external MOSFETs allow arbitrary voltage combinations and higher current scalability beyond 5A.

Availability

LTC2926CUFD#PBF is available at Aetrix Electronics and suitable for FPGA power sequencing, server multi-rail management, and communications baseband supply coordination requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for LTC2926CUFD#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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, formed through the acquisition of Linear Technology in 2017.

The LTC2926CUFD#PBF belongs to ADI's Power Management portfolio, specifically designed for precision analog-controlled power sequencing in high-reliability computing and infrastructure systems where deterministic ramp behavior and fault containment are mandatory.

FAQ

What is the function of the RAMPBUF pin on the LTC2926CUFD#PBF?

The RAMPBUF pin on the LTC2926CUFD#PBF provides a low-impedance buffered replica of the RAMP signal, capable of sourcing or sinking up to ±3mA. It drives the resistive divider networks connected to TRACK1 and TRACK2, ensuring accurate tracking profile generation without loading the sensitive RAMP node. Unlike the high-impedance RAMP pin (which handles only 10µA), RAMPBUF maintains signal integrity across PCB traces and multiple divider branches-critical for consistent multi-rail tracking performance in the LTC2926CUFD#PBF.

How does the LTC2926CUFD#PBF handle fault conditions and recovery?

The LTC2926CUFD#PBF uses a latched fault architecture: assertion of FAULT ≤0.5V, STATUS/PGI ≤1.0V after PGTMR timeout, or VCC <2.4V immediately pulls MGATE, SGATE1, SGATE2, and RSGATE to GND and opens D1/S1 and D2/S2 switches. Recovery requires pulling the ON pin below 0.5V to clear the latch-no automatic retry. This ensures system safety by preventing uncontrolled re-enabling after overvoltage, undervoltage, or loss-of-power events in the LTC2926CUFD#PBF.

Can the LTC2926CUFD#PBF track more than two slave supplies?

No-the LTC2926CUFD#PBF supports exactly two slave supplies via dedicated SGATE1/SGATE2 outputs and FB1/FB2 inputs. Its architecture is optimized for master + dual-slave configurations (e.g., VCORE + VI/O + AUX). To manage three independent rails with tracking, a second LTC2926CUFD#PBF or alternate solution is required. The device does not support daisy-chaining or multiplexing additional channels; all TRACK/FB pairs and gate drivers are fixed-function and non-expandable in the LTC2926CUFD#PBF.

What is the purpose of the RSGATE pin on the LTC2926CUFD#PBF?

The RSGATE pin on the LTC2926CUFD#PBF drives the gates of internal remote sense switches (D1/S1 and D2/S2) and optional external N-MOSFETs. It rises only after MGATE, SGATE1, and SGATE2 reach full enhancement, closing the sense path to compensate for MOSFET V_DS drop in slave supplies. During ramp-down, RSGATE falls below 1.23V before MGATE/SGATEs discharge-ensuring sense switches open first to avoid undershoot. This precise timing coordination is integral to the LTC2926CUFD#PBF's accuracy in high-current applications.

Does the LTC2926CUFD#PBF require external MOSFETs for operation?

Yes-the LTC2926CUFD#PBF is a controller IC and requires external N-channel MOSFETs for all rail control functions. MGATE drives a master MOSFET (e.g., for a 12V rail), SGATE1/SGATE2 drive slave MOSFETs (e.g., for 3.3V/1.8V rails), and RSGATE can drive external sense-switch MOSFETs. No internal power switches exist; the LTC2926CUFD#PBF provides only gate drive signals, current mirroring, and sequencing logic-making external MOSFET selection (e.g., R_DS(on), Q_g, V_GS(th)) critical to system performance.