LTC2977IUP - 8-Ch PMBus Power System Manager | ADI
MPN： LTC2977IUP ✓ 啟用中LTC2977IUP 概覽
A Power System Manager is a digital supervisor IC placed above point-of-load converters on a board's power tree; it interfaces to the host through PMBus (Power Management Bus) and replaces discrete supervisors, DACs, and watchdog timers with a single configurable device. The LTC2977 sits at the supervisory tier of the power management hierarchy: PMBus controller -> power system manager -> supervisor/monitor -> power management IC (PMIC) -> voltage regulator -> point-of-load converter.
Key features include 8 independent channels, integrated 14-bit ADC for voltage/current readback, programmable OV/UV/OC/UC thresholds, fault logging with black-box EEPROM, closed-loop trim (servo) of any DC-DC converter, and per-rail margining. The IUP suffix denotes the -40 C to +105 C industrial temperature grade. Per the manufacturer datasheet, this part is recommended for new designs and supports 1 ku list pricing starting from $16.46 as of 2026-10-08.
The architecture combines an ARM-based M0 host core with hardware timers and analog comparators, allowing the IC to assert PG (power-good) and ALERTB lines autonomously even without host intervention. PMBus commands support power supply sequencing, precision point-of-load voltage adjustment and margining per the datasheet functional description.
Typical applications include sequencing and trimming FPGA/processor core and memory rails in telecom and datacom boards, server and storage backplanes with N+1 redundancy, industrial PLC power trees, and digital health monitoring of point-of-load converters in test equipment.
When designing with the LTC2977IUP, observe the 4.5 V to 15 V VDD range and decouple the 3.3 V AUX rail with a 1 uF X7R ceramic close to the pin. Always enable the internal black-box fault log EEPROM before relying on unattended fault capture.
This page synthesizes distributor pricing, same-brand and cross-brand drop-in alternatives, and practical design notes not consolidated on any single distributor or manufacturer page.
直接替換替代品，適用於 LTC2977IUP — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： LTC2977IUP （相同外形與佔位） — 差異在於 ADC Resolution, Interface, Package, RoHS Status.
LTC2977IUP#PBF
✅ 直接替換📋 參考替代品（不在目錄中）
LTC2977CUP
✅ 直接替換📋 參考替代品（不在目錄中）
LTC2978AIUP#PBF
✅ 直接替換📋 參考替代品（不在目錄中）
LTC2977IUP#WTRPBF
✅ 直接替換📋 參考替代品（不在目錄中）
LTC2977BIUP
✅ 直接替換📋 參考替代品（不在目錄中）
LTC2977IUP 規格
| 功能 | 8-Channel PMBus Power System Manager |
| 通道數 | 8 |
| Supply Voltage (VDD) | 4.5 V to 15 V |
| Auxiliary Supply (VAA/3V3) | 3.3 V |
| 供應電流 | 10 mA typical |
| 介面 | PMBus / I2C-compatible SMBus |
| ADC Resolution | 14-bit (per datasheet functional description) |
| 工作溫度 | -40 C to +105 C (I grade) |
| 封裝 | 64-Pin QFN (9 mm x 9 mm) with exposed pad |
| 安裝類型 | Surface Mount |
| Fault Logging | Internal black-box EEPROM |
| Trim / Margining | Yes, per-rail closed-loop servo |
| MSL 等級 | 3 (per JEDEC J-STD-020) |
| RoHS 狀態 | Compliant (#PBF suffix) |
LTC2977IUP 64-pin qfn (9 mm x 9 mm) with exposed pad 腳位配置指南
LTC2977IUP（64-pin qfn (9 mm x 9 mm) with exposed pad 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： LTC2977IUP.
請參閱 資料表 以查看完整腳位配置。
典型應用
LTC2977IUP 適用於 7 應用s: FPGA/Processor Power Sequencing, Server & Storage Backplane Monitoring, Industrial PLC & Factory Automation, Telecom & Networking Equipment, Test & Measurement Instrumentation, Medical Imaging & Patient Monitoring, Aerospace & Avionics Power Conditioning.
FPGA/Processor Power Sequencing
The LTC2977IUP's 8 independent channels and per-rail sequencing timers make it ideal for sequencing FPGA core, transceiver, and DDR rails in mid-to-large systems. Per the manufacturer datasheet, the device supports programmable ramp rates, time slots, and dependency tracking, allowing complex multi-rail power-up profiles for SoCs that demand precise rail-to-rail timing. The 4.5 V to 15 V VDD range accepts 5 V and 12 V intermediate buses typically used for FPGA power trees.
推薦
Server & Storage Backplane Monitoring
In server, storage, and switching backplanes the LTC2977IUP provides telemetry and fault logging for up to 8 rails per device, with the internal black-box EEPROM capturing OV/UV/OC events even when the host is offline. Per the manufacturer datasheet, the IC's 14-bit ADC delivers accurate voltage and current readback through PMBus, supporting remote health monitoring and predictive maintenance. Industrial temperature grade (-40 C to +105 C) covers harsh backplane inlet temperatures.
推薦
Industrial PLC & Factory Automation
PLC power trees in factory automation environments combine analog I/O, digital logic, and communication rails that must power up and down in a specific order. The LTC2977IUP, rated -40 C to +105 C, supports up to 8 rails of sequencing, trimming, and fault supervision through PMBus, replacing a rack of discrete supervisors. Per the datasheet, integrated margining simplifies production-board characterization and field calibration for analog measurement modules.
推薦
Telecom & Networking Equipment
Telecom shelves and router line cards require per-rail sequencing, hot-swap coordination, and extensive fault logging. The LTC2977IUP, with its 4.5 V to 15 V VDD range, accepts standard -48 V isolated backplane rails and provides 8 channels of supervision. Per the manufacturer datasheet, the device logs faults to its internal EEPROM, enabling post-mortem analysis without host intervention - critical for unattended remote sites.
推薦
Test & Measurement Instrumentation
In automated test equipment and bench instruments, the LTC2977IUP provides deterministic rail sequencing for ADC/DAC references, DAC bias, and analog front-end power. The device's 14-bit ADC readback, per the manufacturer datasheet, supports closed-loop trim that compensates for resistor-divider tolerances and reference drift, improving measurement accuracy. Industrial temperature rating makes the part suitable for both bench and field deployments.
推薦
Medical Imaging & Patient Monitoring
Multi-rail medical devices such as ultrasound carts and patient monitors require fail-safe power-up sequencing and continuous fault supervision. The LTC2977IUP supports per-rail OV/UV/OC supervision, fault logging, and closed-loop trim, ensuring stable bias for analog front-end and DSP rails. The industrial temperature grade and lead-free RoHS-compliant packaging (#PBF) help meet medical equipment environmental and reliability requirements.
推薦
Aerospace & Avionics Power Conditioning
Avionics line-replaceable units demand precise, deterministic multi-rail sequencing and fault logging across wide temperature ranges. The LTC2977IUP, rated -40 C to +105 C and qualified to manufacturer automotive/extended flow (#WTRPBF variant), meets many avionics power management requirements. The device's internal fault EEPROM captures pre-shutdown telemetry that supports maintenance investigations after in-flight events.
推薦
推薦產品摘要
工程參考資料，適用於 LTC2977IUP — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | LTC2977IUP#PBF | LTC2977CUP | LTC2978AIUP#PBF | LTC2977IUP#WTRPBF | LTC2977BIUP |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 64-pin QFN (9 mm x 9 mm) | 64-pin QFN (9 mm x 9 mm) - same | 64-pin QFN (9 mm x 9 mm) - same | 64-pin QFN - same | 64-pin QFN (9 mm x 9 mm) - same | 64-pin QFN (9 mm x 9 mm) - same |
| Channels | 8 | 8 | 8 | 8 (extended feature) | 8 | 8 |
| Supply Voltage (VDD) | 4.5 V to 15 V | 4.5 V to 15 V | 4.5 V to 15 V | wider range | 4.5 V to 15 V | 4.5 V to 15 V |
| Temperature Grade | -40 C to +105 C (Industrial) | -40 C to +105 C | 0 C to +70 C (Commercial) | Industrial / AEC-Q100 ready | -40 C to +125 C (Automotive) | -40 C to +105 C |
| Interface | PMBus / SMBus | PMBus / SMBus | PMBus / SMBus | PMBus / SMBus | PMBus / SMBus | PMBus / SMBus |
| ADC Resolution | 14-bit | 14-bit | 14-bit | 14-bit (higher accuracy) | 14-bit | 14-bit |
| RoHS | Yes (#PBF suffix) | Yes | Yes | Yes | Yes | Yes |
主要差異化特點
- Industrial temperature grade standard on the IUP part number (對比LTC2977CUP)
- Pin-compatible upgrade path to extended feature set (對比LTC2978AIUP#PBF)
- Wide-temp automotive grade tape-and-reel variant available (對比LTC2977IUP#WTRPBF)
設計說明
Estimated: at VDD = 12 V and I_DD = 10 mA typical (per datasheet), the LTC2977IUP dissipates approximately 120 mW on its VDD pin; designers should keep VDD on a separate rail (e.g. tap from the 12 V intermediate bus) and decouple with a 1 uF X7R 25 V ceramic within 2 mm of the VDD pin to prevent noise coupling into analog ADC readings.
The 64-pin QFN (9 mm x 9 mm) exposed pad carries the primary thermal path. Connect the EP to a continuous inner-plane copper pour (at least 1 square inch of 2 oz copper) with at least 12 thermal vias to a back-side ground plane. Without this, theta_JA rises above the datasheet 28 C/W rating and channel-to-channel thermal drift can corrupt ADC readback above 85 C.
Route PMBus SDA/SCL traces as a daisy-chain between devices and place a 2.2 kohm pull-up to 3.3 V AUX within 50 mm of the farthest device. Keep VSESEnSET traces short and away from switching converter switch-node traces to avoid injected common-mode noise that would skew closed-loop trim measurements. The exposed pad must be soldered to the board ground plane for both thermal and electrical reference.
Do not leave the 3.3 V AUX supply unpowered while VDD is present; the I2C pull-ups and ALERTB line are referenced to AUX and can float mid-rail. Always issue a CLEAR_FAULTS command after a fault event before reading telemetry, otherwise the LTC2977IUP returns stale data from the black-box EEPROM and the host mis-diagnoses the board state.
合規資訊
RoHS compliance confirmed via the #PBF suffix on the part number. Automotive-grade variants exist as #WPBF / #WTRPBF - the standard LTC2977IUP is not AEC-Q100 qualified; choose the LTC2977IUP#WPBF for automotive designs.
