Analog Devices Inc. LTC2974IUP

Overview

LTC2974IUP from Analog Devices is a 4-channel PMBus-compatible power system manager IC designed for autonomous sequencing, precise voltage margining, and real-time telemetry in FPGA and ASIC power delivery systems. It supports ±0.25% trimmed output voltage accuracy, 10-bit ADCs per channel for voltage/current/temperature monitoring, and hardware-based fault response with EEPROM black-box logging. It is used in high-reliability Arria 10 and Virtex UltraScale FPGA power rails to enforce strict up/down sequencing and SmartVID-compliant voltage adaptation.

For engineers reviewing the LTC2974IUP datasheet, LTC2974IUP pinout, LTC2974IUP application, or LTC2974IUP equivalent, this device delivers deterministic time-based sequencing across four independent power rails, supports PMBus VOUT_COMMAND and VOUT_MODE commands for dynamic voltage adjustment, enables hardware-fault-triggered shutdown without host intervention, and provides traceable telemetry for thermal and load transient analysis in multi-rail embedded systems.

Technical Context

The LTC2974IUP implements a dedicated sequencer engine with programmable timing resolution down to 1 ms, supporting both time-based and event-driven sequencing modes. Each of its four channels includes independent enable control, programmable undervoltage/overvoltage thresholds (±0.5% accuracy), and a dedicated 10-bit ADC for rail voltage sensing.

It integrates a PMBus 1.2-compliant interface with full command set support-including READ_VIN, READ_IOUT, READ_TEMPERATURE_1, MARGIN_HIGH/LOW, and STORE_DEFAULT_ALL-and features nonvolatile EEPROM for fault logs, configuration retention, and startup defaults. Its FAULT and SHARE_CLK pins enable synchronized multi-IC fault handling and shared timing coordination across PSM devices.

Key Specifications

Pinout & Package

Package: 32-pin QFN (5 mm × 5 mm, 0.5 mm pitch), exposed pad for thermal dissipation and ground connection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power system management applications.

Compared with LTC2975CUF and LTC2977IUP, the LTC2974IUP delivers identical sequencing determinism and SmartVID responsiveness at lower cost and thermal footprint-making it the preferred choice for standard commercial FPGA power systems where 4-rail coverage and 0°C to +70°C operation are sufficient.

Availability

LTC2974IUP is available at Aetrix Electronics and suitable for FPGA power management, telecom line card sequencing, and industrial PLC power integrity applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LTC2974IUP 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. is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and power management.

The LTC2974IUP belongs to Analog Devices' Power System Management (PSM) product line, engineered specifically to replace discrete sequencing and supervision circuits in complex multi-rail FPGA, ASIC, and DSP power systems.

FAQ

What is the primary function of the LTC2974IUP in an FPGA power system?

The LTC2974IUP serves as a 4-channel power system manager that autonomously sequences, monitors, and protects FPGA power rails. It enforces precise up/down timing per Arria 10 or Virtex UltraScale specifications, executes SmartVID voltage commands via PMBus, and logs faults to EEPROM without host CPU involvement. The LTC2974IUP ensures reliable power-on-reset, prevents timing violations, and minimizes unnecessary power dissipation through ±0.25% voltage accuracy.

Does the LTC2974IUP support SmartVID2 protocol for dynamic FPGA core voltage adjustment?

Yes, the LTC2974IUP fully supports SmartVID2 through native PMBus VOUT_COMMAND and VOUT_MODE command execution. It accepts 10 mV voltage step commands every 10 ms and settles within ±30 mV of target in ≤10 ms-meeting Altera's SmartVID2 timing and accuracy requirements. The LTC2974IUP uses its internal 10-bit ADC and servo loop to maintain commanded voltage without host intervention during FPGA operation.

How does the LTC2974IUP handle fault conditions across multiple power rails?

The LTC2974IUP detects overvoltage, undervoltage, overtemperature, and current faults on each of its four channels using programmable thresholds. Upon detection, it asserts the open-drain FAULT pin within 1 µs, triggering coordinated shutdown across all connected PSM devices via the shared FAULT bus. Simultaneously, it saves timestamped rail voltages, temperatures, and sequence state to internal EEPROM-providing complete black-box fault context for post-mortem analysis. This behavior is fully hardware-based and requires no firmware or host CPU action.

Can the LTC2974IUP be used alongside other Analog Devices PSM ICs like the LTC2977 or LTM4676A?

Yes, the LTC2974IUP is designed for seamless interoperability with other Analog Devices PSM devices via the SHARE_CLK and FAULT buses. It synchronizes timing with LTC2977 (8-channel), LTC2975 (4-channel), and LTM4676A µModule regulators to execute unified up/down sequences across 16+ rails. All devices share the same PMBus command set and EEPROM configuration structure, enabling consistent system-level power management without custom software abstraction layers. The LTC2974IUP functions identically whether deployed standalone or as part of a larger PSM network.

What package and thermal characteristics does the LTC2974IUP have?

The LTC2974IUP is housed in a 32-pin 5 mm × 5 mm QFN package with exposed thermal pad, rated for 0°C to +70°C ambient operation. Its thermal resistance θ_JA is 42°C/W, and the exposed pad must be soldered to a minimum 100 mm² copper pour for effective heat dissipation. The device includes an integrated die temperature sensor with ±2°C accuracy and programmable overtemperature interrupt-allowing thermal-aware voltage margining and automatic derating in high-density PCB layouts. This thermal design enables reliable operation in FPGA carrier cards and industrial control modules.