My Inquiry
My Account
Analog Devices Inc. LTC3875EUJ#PBF
- Part No.:
- LTC3875EUJ#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 40-WFQFN Exposed Pad
- Datasheet:
-
LTC3875EUJ#PBF.pdf
- Description:
- IC REG CTRLR BUCK 40QFN
- Quantity:
- Payment:
- Shipping:
Inventory:143
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3875EUJ#PBF from Analog Devices (formerly Linear Technology) is a dual-output, 2-phase synchronous step-down DC/DC controller driving all-N-channel MOSFET stages. It enables high-efficiency, high-current regulation (e.g., 1.2V/60A) using low-DCR inductor sensing with ±0.5% 0.6V reference accuracy, 4.5V–38V input range, and DCR temperature compensation. It targets server VRMs and telecom power systems requiring precise thermal balancing and remote sensing.
For engineers reviewing the LTC3875EUJ#PBF datasheet, LTC3875EUJ#PBF pinout, LTC3875EUJ#PBF application, or LTC3875EUJ#PBF equivalent, key selection criteria include dual-phase current-mode control with programmable DCR sensing thresholds (10–30mV), phase-lockable 250–720kHz operation, thermal balancing for multichip outputs, and 40-lead 6mm × 6mm QFN packaging with exposed PGND pad.
Technical Context
The LTC3875EUJ#PBF implements two independent current-mode control loops with 180° phase interleaving to reduce input ripple and EMI. Each channel integrates dual differential amplifiers for true remote sensing and employs a unique signal-to-noise-enhanced DCR sensing architecture that supports inductors as low as 0.32mΩ while minimizing switching jitter.
It features integrated thermal balancing via TCOMP1/2 and TAVG pins, enabling per-phase current adjustment across multiple ICs to equalize thermal stress. The controller supports forced CCM, Burst Mode™, or pulse-skipping operation via MODE/PLLIN, and provides clock synchronization (CLKOUT/PHASMD) for up to 12-phase expansion.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V to 38V - supports wide bus voltages including 5V, 12V, and 24V industrial/telecom rails. |
| Output Voltage Accuracy | ±0.5% at 0.6V reference - ensures tight regulation for sub-1V CPU/GPU core supplies. |
| Current Sense Threshold | Programmable 10mV to 30mV (DC mode) - enables accurate low-DCR inductor sensing without sense resistors. |
| Switching Frequency | 250kHz to 720kHz, phase-lockable - allows EMI optimization and multi-phase synchronization. |
| Package | 40-lead 6mm × 6mm QFN (UJ), 0.5mm pitch, exposed PGND pad - optimized for high-power thermal dissipation (θJA = 33°C/W). |
| Thermal Shutdown | 160°C with 10°C hysteresis - protects against sustained overload or poor heatsinking in dense PCB layouts. |
| Remote Sensing | Dual true differential VOSNS+/VOSNS− inputs per channel - eliminates IR drop errors in high-current PCB traces. |
Pinout & Package
Package: 40-lead plastic QFN (UJ), 6mm × 6mm, 0.5mm pitch, exposed SGND/PGND pad (Pin 41) - requires soldering to PCB thermal plane for optimal power dissipation and noise immunity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| TK/SS1, TK/SS2 (1, 8) | Soft-start & tracking input | Internal 1.25µA current ramps external capacitor to control output voltage slew rate or enable supply sequencing. |
| VOSNS1+, VOSNS2+ (2, 6) | Positive remote sense input | Connects to top of output divider to reject PCB trace resistance error in high-current applications. |
| VOSNS1–, VOSNS2– (3, 7) | Negative remote sense input | Must connect to load-side ground point - completes Kelvin sensing loop for <±10mV regulation error. |
| ITH1, ITH2 (4, 5) | Error amplifier output / current threshold | Voltage sets peak inductor current limit; used for loop compensation and current foldback programming. |
| TAVG (13) | Average temperature summing node | Resistor-to-ground sums mirrored TCOMP currents across multiple LTC3875s for system-level thermal balancing. |
| FREQ (15) | Oscillator frequency programming | 10µA sink current - resistor to ground sets nominal frequency (e.g., 100kΩ → ~500kHz). |
| PGOOD (19) | Open-drain power-good indicator | Asserts low when either output deviates >±7.5% from setpoint after 20µs debounce - enables sequencer handshaking. |
| EXTVCC (24) | External bias supply input | Bypasses internal LDO when >4.7V applied - reduces power loss and heat in high-current designs. |
| INTVCC (25) | Internal 5.5V regulator output | Powers gate drivers and analog circuitry; requires ≥4.7µF low-ESR ceramic/tantalum decoupling to PGND. |
| BG1, BG2 (27, 23) | Bottom N-MOSFET gate driver | Drives low-side FET gates from INTVCC to PGND; 1.1Ω pull-down RDS(ON) ensures fast turn-off. |
| TG1, TG2 (29, 21) | Top N-MOSFET gate driver | Floating output referenced to SW node; 1.5Ω pull-down RDS(ON) minimizes shoot-through risk. |
| SW1, SW2 (30, 20) | Switch node connection | Connects to inductor center-tap; swings from near-GND to VIN - requires low-inductance layout and Schottky catch diode if needed. |
| CLKOUT (31) | Phase-programmable clock output | Provides synchronized timing for multi-phase stacks; phase offset set by PHASMD (0°, 60°, 90°, 120°, or 180°). |
| MODE/PLLIN (33) | Mode select & external sync input | Configures CCM/Burst/Pulse-Skipping or accepts external clock for PLL lock - no external compensation required. |
| RUN1, RUN2 (34, 16) | Channel enable control | 1.22V threshold with 80mV hysteresis - supports independent channel sequencing and fault shutdown. |
| ILIM (35) | Current limit range select | Resistor divider selects one of five DCR sense thresholds (10/15/20/25/30mV) - calibrates for inductor DCR tolerance. |
| TCOMP1/ITEMP1, TCOMP2/ITEMP2 (37, 12) | Temperature sensor input | Accepts NTC thermistors near inductors to compensate DCR drift or enable thermal balancing across phases. |
| SNSD1+, SNSD2+ (38, 11) | DC current sense comparator + | Enables low-DCR sensing; grounding disables novel DCR mode and reverts to standard 5× current limit scaling. |
| SNS1–, SNS2– (39, 10) | AC/DC current sense comparator – | Connects to output rail - forms differential pair with SNSA+/SNSD+ for combined AC+DC current measurement. |
| SNSA1+, SNSA2+ (40, 9) | AC current sense comparator + | Used with SNSD+ to skew DCR network and amplify AC ripple component by 5× for improved SNR. |
| SGND/PGND (41) | Exposed thermal pad | Mandatory solder connection to PCB ground plane - serves as primary thermal path and low-impedance return for power and signal grounds. |
Key Features
| Feature | Design Value |
|---|---|
| Dual 180° interleaved controllers | Reduces input capacitance requirement by ~50% and cuts RMS input ripple current vs single-phase design. |
| Low-DCR current sensing (10–30mV) | Eliminates power loss and board space of discrete current-sense resistors while maintaining <1% current measurement error. |
| Programmable DCR temperature compensation | Uses external NTC on TCOMP pins to maintain constant current limit over –40°C to 125°C ambient. |
| Thermal balancing across multiple ICs | Shares thermal load between parallel LTC3875s via TAVG summation - extends lifetime in high-density VRMs. |
| True remote differential sensing (x2) | Rejects up to 50mV of IR drop in 60A+ power paths - critical for sub-1% output voltage regulation accuracy. |
| Phase-lockable clock with programmable offset | Enables seamless scaling to 12-phase systems using CLKOUT/PHASMD without external timing ICs. |
Applications
| Server CPU/GPU Core Power | Telecom Base Station DC-DC Conversion |
|---|---|
Use Scenario: Delivering tightly regulated 0.8V–1.2V at up to 120A to modern x86 or AI accelerators in 1U rack servers. IC Role / Device Role / Timing Role: Dual-phase synchronous buck controller managing two parallel 60A power stages with interleaved timing and thermal load sharing. Use Value: Achieves >92% efficiency at 60A/1.2V while maintaining ±5mV output accuracy via remote sensing and ±0.5% reference - directly enabling higher processor boost clocks. | Use Scenario: Converting –48V telecom rectified input to stable +3.3V/+5V intermediate rails for RF transceivers and baseband processors. IC Role / Device Role / Timing Role: High-voltage-input dual-output controller supporting wide VIN range (4.5V–38V) with independent soft-start and tracking for multi-rail sequencing. Use Value: Enables single-chip solution for dual-rail generation with independent RUN/TK-SS control - reducing BOM count and improving startup reliability in distributed power architectures. |
| Industrial PLC Power Management | High-Density DC Power Distribution |
Use Scenario: Providing isolated, well-regulated 3.3V and 5V supplies for I/O modules and real-time controllers in harsh factory environments. IC Role / Device Role / Timing Role: Dual-output controller with robust UVLO (3.7V), OVP (±7.5%), and thermal shutdown (160°C) for continuous operation under brownout or overload conditions. Use Value: Guarantees uninterrupted operation during line sags via wide input range and fast transient response - critical for deterministic motion control timing. | Use Scenario: Building scalable, modular 48V-to-12V/5V power bricks for datacenter rack-level distribution with hot-swap capability. IC Role / Device Role / Timing Role: Phase-expandable controller supporting up to 12-phase operation via CLKOUT synchronization - enabling flexible power stage scaling from 60A to 720A. Use Value: Reduces per-amp cost and improves thermal uniformity across large power modules - essential for liquid-cooled or fanless high-density deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-phase synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3876EUJ#PBF | Includes integrated MOSFET drivers with higher peak current (4A vs 2.5A), enhanced current-mode stability, and improved light-load efficiency via adaptive burst mode. | Targeted at newer-generation VRMs requiring tighter transient response and lower quiescent current (<10mA vs 7mA typical). | Select LTC3876EUJ#PBF when upgrading for higher-frequency operation (>1MHz capability) or when driving larger gate charges without external driver buffers. |
| MP2960AGQSE-LF-Z | Monolithic dual-phase controller with integrated drivers and PMBus interface; lacks DCR temperature compensation and thermal balancing but offers digital telemetry and fault logging. | Designed for smart power systems requiring real-time monitoring, margining, and dynamic voltage scaling via I²C/PMBus. | Choose MP2960AGQSE-LF-Z only when digital control, telemetry, or firmware-upgradable features outweigh the need for analog DCR compensation and thermal balancing. |
Compared with LTC3876EUJ#PBF and MP2960AGQSE-LF-Z, the LTC3875EUJ#PBF delivers superior analog precision for low-DCR sensing and deterministic thermal management in high-reliability analog power systems - making it preferred for legacy server VRMs and telecom infrastructure where digital complexity adds unnecessary risk.
Availability
LTC3875EUJ#PBF is available at Aetrix Electronics and suitable for server motherboard design, telecom power shelf development, and industrial PLC power supply engineering requiring stable component supply and long-term lifecycle support.
Supply support for LTC3875EUJ#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 full product support, documentation, and manufacturing continuity for the LTC portfolio.
The LTC3875EUJ#PBF belongs to Linear's high-performance power controller family, designed specifically for high-current, multi-phase DC/DC conversion in computing, communications, and industrial applications demanding precision analog regulation and thermal resilience.
FAQ
What is the package type and thermal performance of the LTC3875EUJ#PBF?
The LTC3875EUJ#PBF uses a 40-lead 6mm × 6mm plastic QFN (UJ) package with an exposed PGND pad. Its thermal characteristics include θJA = 33°C/W and θJC = 2.0°C/W, enabling efficient heat transfer to the PCB when the exposed pad is properly soldered to a thermal plane. This makes the LTC3875EUJ#PBF suitable for high-power density applications such as server VRMs where junction temperature must remain below 125°C under full load.
How does the LTC3875EUJ#PBF implement low-DCR current sensing?
The LTC3875EUJ#PBF implements low-DCR current sensing using dual-path comparator architecture: SNSA+ senses AC ripple voltage across the inductor's DCR, while SNSD+ senses the DC voltage drop. Combined, they allow accurate current measurement down to 10mV threshold with programmable gain. The LTC3875EUJ#PBF also supports DCR temperature compensation via external NTC thermistors on TCOMP1/2 pins to maintain consistent current limiting across –40°C to 125°C.
Can the LTC3875EUJ#PBF be synchronized to an external clock source?
Yes, the LTC3875EUJ#PBF supports external synchronization via the MODE/PLLIN pin. Applying a clean square wave (250kHz–720kHz) to this pin forces the internal oscillator into phase-locked operation, eliminating beat frequencies and enabling deterministic EMI reduction. The internal PLL requires no external components, and the LTC3875EUJ#PBF maintains lock even during input voltage transients - critical for multi-rail synchronized power systems.
What is the purpose of the TAVG pin on the LTC3875EUJ#PBF?
The TAVG pin on the LTC3875EUJ#PBF serves as the average temperature summing node for thermal balancing across multiple LTC3875EUJ#PBF ICs or phases. When ENTMPB is grounded, currents mirrored from each TCOMP pin are summed at TAVG via external resistors. This enables automatic per-phase current redistribution to equalize thermal stress - a key feature for paralleling controllers in high-current VRMs where uneven heating degrades reliability.
Does the LTC3875EUJ#PBF support independent enable and soft-start for each output?
Yes, the LTC3875EUJ#PBF provides fully independent control for each channel: RUN1/RUN2 pins enable/disable each controller separately with 1.22V threshold and 80mV hysteresis, while TK/SS1/TK/SS2 pins allow individual soft-start ramping or supply tracking. This enables precise power sequencing in multi-rail systems - for example, ramping a 1.2V core rail before a 3.3V I/O rail - without requiring external timers or supervisors.
LTC3875EUJ#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 40-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Number of Outputs:
- 2
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 4.5V ~ 38V
- Frequency - Switching:
- 250kHz ~ 720kHz
- Duty Cycle (Max):
- -
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable, Frequency Control, Phase Control, Power Good, Soft Start, Tracking
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 40-QFN (6x6)
LTC3875EUJ#PBF FAQ
1.How can I place an order for LTC3875EUJ#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3875EUJ#PBF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LTC3875EUJ#PBF reliable?
The price and inventory of LTC3875EUJ#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3875EUJ#PBF is usually 5 days.
3.What payment methods are accepted for LTC3875EUJ#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3875EUJ#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3875EUJ#PBF?
LTC3875EUJ#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3875EUJ#PBF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LTC3875EUJ#PBF?
For technical support, including LTC3875EUJ#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3875EUJ#PBF requirements.
6.How does Aetrix verify that LTC3875EUJ#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3875EUJ#PBF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LTC3875EUJ#PBF meets industry standards.
7.What is the process for return or replacement of LTC3875EUJ#PBF?
All LTC3875EUJ#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3875EUJ#PBF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LTC3875EUJ#PBF part is unused and in its original packaging.
Return procedure for LTC3875EUJ#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3875EUJ#PBF Tags
-
UCC28C45DR
Texas Instruments
-
UCC28C40DR
Texas Instruments
-
UCC28C43DR
Texas Instruments
-
ZXSC410E6TA
Diodes Incorporated
-
LM3524DMX/NOPB
Texas Instruments
-
LM3489MMX/NOPB
Texas Instruments
-
MIC2102YML-TR
Microchip Technology
-
LM5148RGYR
Texas Instruments
-
TL598CDR
Texas Instruments
-
LM5155DSSR
Texas Instruments
-
LM25085MYX/NOPB
Texas Instruments
-
UCC2813DTR-0
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
