My Inquiry
My Account
Analog Devices Inc. LTC3856EFE#TRPBF
- Part No.:
- LTC3856EFE#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 38-TFSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LTC3856EFE#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK 38TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,098
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3856EFE#TRPBF from Analog Devices (formerly Linear Technology) is a dual-channel PolyPhase® synchronous step-down DC/DC controller driving all-N-channel MOSFET stages for high-current 1.5V/50A power delivery. It features true remote differential voltage sensing, DCR/RSense current monitoring with temperature compensation, phase-lockable 250–770kHz operation, and Active Voltage Positioning (AVP) for CPU/GPU VRMs in telecom and server applications.
For engineers reviewing the LTC3856EFE#TRPBF datasheet, LTC3856EFE#TRPBF pinout, LTC3856EFE#TRPBF application, or LTC3856EFE#TRPBF equivalent, this page delivers verified technical context, exact pin functions per TSSOP-38 package, confirmed efficiency curves up to 95%, AVP load-line implementation details, and validated alternatives for multi-phase buck controller selection.
Technical Context
The LTC3856EFE#TRPBF implements a constant-frequency current-mode control architecture with two independent PWM channels operating out-of-phase to reduce input/output ripple and EMI. Its differential amplifier (gain = 0.998–1.002 V/V, ±2mV offset) enables precise remote sense at the load, while programmable DCR temperature compensation maintains current-sense accuracy across –40°C to 125°C.
It supports three light-load modes-Burst Mode®, Stage Shedding™, and forced continuous conduction-selected via the MODE pin. The ISET pin programs both Burst Mode threshold and Stage Shedding current limit, and ILIM selects one of three maximum sense thresholds (25/45/68 mV for E-grade), enabling flexible current protection scaling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V to 38V - supports 5V, 12V, and 24V intermediate bus systems without external regulators. |
| Output Voltage Range | 0.6V to 3.3V with differential sensing - matches modern CPU/GPU core voltage requirements with remote sense accuracy. |
| Reference Accuracy | ±0.75% at 0.6V - ensures tight regulation tolerance for sub-1V loads critical in digital ICs. |
| Switching Frequency | 250kHz to 770kHz, phase-lockable - enables synchronized multi-phase operation and EMI reduction via frequency dithering. |
| Current Sensing | RSENSE or DCR with programmable tempco - eliminates need for precision shunts and enables accurate thermal derating in high-temp environments. |
| Efficiency | Up to 95% at 1.5V/50A - achieved via low-RDS(ON) gate drivers (TG RDOWN = 1.5Ω, BG RDOWN = 1.1Ω) and optimized dead-time control. |
| Package | 38-pin TSSOP (FE) with exposed SGND/PGND pad - provides thermal performance θJA = 25°C/W for high-power density layouts. |
Pinout & Package
Package: 38-lead plastic TSSOP (FE), exposed pad (Pin 39) soldered to SGND/PGND for thermal and electrical integrity. θJA = 25°C/W, TJMAX = 125°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| TG1, TG2 | Top gate driver outputs | Drive N-MOSFET gates with 2.6Ω pull-up / 1.5Ω pull-down RDS(ON); require bootstrap capacitors tied to BOOST1/BOOST2. |
| BG1, BG2 | Bottom gate driver outputs | Drive N-MOSFET sources with 2.4Ω pull-up / 1.1Ω pull-down RDS(ON); referenced to PGND1/PGND2. |
| SENSE1+, SENSE1− SENSE2+, SENSE2− |
Dual-channel current sense inputs | Accept DCR network or shunt resistor signals; support ±1µA bias current and programmable max threshold (25–68 mV). |
| DIFFP, DIFFN, DIFFOUT | Differential remote sense amplifier | DIFFP connects directly to load point; DIFFN to output capacitor negative; DIFFOUT feeds VFB via resistive divider for <±0.75% regulation. |
| AVP | Active Voltage Positioning programming | Connect 1kΩ to DIFFP to enable load-line droop; sinks 250µA / sources 2mA to set VOUT vs. ILOAD slope for CPU VRM compliance. |
| TK/SS | Soft-start and tracking input | 1.25µA internal current charges external capacitor for linear VOUT ramp; also accepts master supply voltage for rail tracking. |
| MODE | Light-load mode select | SGND = forced continuous; FLOAT = Burst Mode®; INTVCC = Stage Shedding™ - no external components needed. |
| ILIM | Current sense threshold range | GND/FLOAT/INTVCC selects 25/45/68 mV max sense voltage - scales overcurrent protection without changing RSENSE or DCR network. |
Key Features
| Feature | Design Value |
|---|---|
| PolyPhase® dual-channel control | Reduces input/output capacitance by >50% and lowers RMS input current ripple versus single-phase designs. |
| True remote differential sensing | Compensates for PCB IR drop up to 3.3V output range with <2mV offset and 100dB PSRR - essential for <1% load regulation. |
| Programmable DCR temperature compensation | ITEMP pin draws 9–11µA to bias NTC thermistor - maintains current limit accuracy across full –40°C to 125°C junction range. |
| Stackable for up to 12-phase operation | CLKOUT and PLLIN pins enable synchronization of up to six LTC3856 devices - scalable for >200A VRMs without external clock generators. |
| Active Voltage Positioning (AVP) | AVP pin sets load-line droop slope matching Intel VRM specs - eliminates need for external op-amps or complex compensation networks. |
Applications
| Telecom Server VRM | Data Center CPU Power |
|---|---|
|
Use Scenario: 1.5V/50A core supply for dual-socket Xeon servers with dynamic load steps up to 50A/µs. IC Role / Device Role / Timing Role: Dual-channel PolyPhase® controller managing two interleaved 25A phases with out-of-phase switching to minimize input ripple. Use Value: Achieves 95% peak efficiency and <35mV load transient undershoot using AVP and differential remote sense at the CPU socket. |
Use Scenario: High-density 0.8V/60A GPU power delivery in AI accelerator cards with strict thermal constraints. IC Role / Device Role / Timing Role: Primary controller with Stage Shedding™ mode - dynamically disables one phase below 20A to maintain >90% efficiency at light loads. Use Value: Reduces quiescent current to 40µA in shutdown and extends battery backup runtime during idle periods. |
| Industrial PLC Power | Medical Imaging System |
|
Use Scenario: 3.3V/30A auxiliary supply for FPGA-based control modules requiring low-noise, high-reliability operation. IC Role / Device Role / Timing Role: Synchronous buck controller with Burst Mode® enabled via floating MODE pin - suppresses audible noise and minimizes standby losses. Use Value: Maintains <±1% output regulation across –40°C to 85°C ambient using DCR sensing and integrated tempco compensation. |
Use Scenario: 1.2V/40A imaging processor supply in MRI subsystems where EMI must be minimized near sensitive analog front-ends. IC Role / Device Role / Timing Role: Phase-locked multi-phase controller synchronized to system clock via PLLIN - eliminates beat frequencies in spectral noise profile. Use Value: Cuts peak-to-peak input ripple by 70% versus single-phase, reducing conducted EMI filter size and cost. |
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 |
|---|---|---|---|
| MP2940AGQ-PS | Integrated MOSFET drivers + 5V LDO; fixed 600kHz freq; no differential sense or AVP. | Suitable for space-constrained 12V-in/1.2V-out apps where remote sense and load-line control are not required. | Choose MP2940AGQ-PS when board area is critical and system-level voltage positioning is handled externally. |
| ISL95812IRZ | Supports 3-phase stacking; includes SMBus interface; requires external VREF; no DCR tempco. | Targeted at notebook VRMs with telemetry and dynamic VID updates - lacks industrial temp grade and EXTVCC flexibility. | Choose ISL95812IRZ only if SMBus configuration and 3-phase scalability outweigh need for wide VIN and robust thermal compensation. |
Compared with MP2940AGQ-PS and ISL95812IRZ, the LTC3856EFE#TRPBF uniquely combines differential remote sensing, programmable AVP, DCR temperature compensation, and 4.5–38V input range - making it the only option qualified for high-accuracy, high-reliability telecom and medical 2-phase VRMs across –40°C to 125°C.
Availability
LTC3856EFE#TRPBF is available at Aetrix Electronics and suitable for telecom server VRMs, data center CPU power supplies, and industrial PLC power systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for LTC3856EFE#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 acquired Linear Technology in 2017 and maintains full product support, documentation, and manufacturing continuity for all Linear-branded power ICs.
The LTC3856EFE#TRPBF belongs to Linear's PolyPhase® controller family, designed specifically for high-efficiency, multi-phase synchronous buck conversion in computing, networking, and industrial infrastructure where precision regulation and thermal robustness are mandatory.
FAQ
What is the maximum supported output current for the LTC3856EFE#TRPBF?
The LTC3856EFE#TRPBF itself does not deliver current-it drives external N-channel MOSFETs. In a typical 2-phase design with 0.33µH inductors and appropriate FETs, the LTC3856EFE#TRPBF enables up to 50A total output (25A per phase) at 1.5V, as validated in the datasheet's TA01a application circuit. Higher currents are achievable with optimized layout, thermal management, and phase stacking.
Does the LTC3856EFE#TRPBF support remote voltage sensing, and how is it implemented?
Yes, the LTC3856EFE#TRPBF supports true remote voltage sensing via its integrated differential amplifier. Connect DIFFP directly to the load point, DIFFN to the output capacitor ground, and feed DIFFOUT into VFB through a resistive divider. This achieves <±0.75% regulation accuracy at the load, compensating for PCB trace resistance and eliminating local feedback errors.
How does Active Voltage Positioning (AVP) work on the LTC3856EFE#TRPBF?
AVP on the LTC3856EFE#TRPBF is implemented by connecting a resistor between AVP and DIFFP. The AVP pin sinks 250µA and sources 2mA, creating a controlled voltage drop proportional to load current. This produces a programmable load-line droop (e.g., 0.5mΩ) that matches Intel VRM specifications-ensuring stable CPU operation under dynamic load transients without external circuitry.
Can the LTC3856EFE#TRPBF operate with DCR current sensing, and what compensation is provided?
Yes, the LTC3856EFE#TRPBF supports DCR current sensing with integrated temperature compensation. The ITEMP pin sources 9–11µA to bias an external NTC thermistor placed near the inductor. This adjusts the current sense threshold in real time to counteract copper DCR drift, maintaining ±3% current limit accuracy from –40°C to 125°C without calibration.
What are the key differences between the LTC3856EFE#TRPBF and the QFN-packaged LTC3856EUH#TRPBF?
The LTC3856EFE#TRPBF uses a 38-pin TSSOP package (θJA = 25°C/W), while the LTC3856EUH#TRPBF uses a 32-pin 5mm × 5mm QFN (θJA = 34°C/W). Pinouts differ: TSSOP exposes SGND/PGND on Pin 39; QFN exposes it on Pin 33. Both share identical electrical specs, but the TSSOP offers better thermal performance for high-continuous-current applications, whereas the QFN saves board area.
LTC3856EFE#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- PolyPhase®
- Package/Case:
- 38-TFSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- 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 ~ 770kHz
- Duty Cycle (Max):
- 94%
- 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:
- 38-TSSOP-EP
LTC3856EFE#TRPBF FAQ
1.How can I place an order for LTC3856EFE#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3856EFE#TRPBF 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 LTC3856EFE#TRPBF reliable?
The price and inventory of LTC3856EFE#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3856EFE#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3856EFE#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3856EFE#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3856EFE#TRPBF?
LTC3856EFE#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3856EFE#TRPBF 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 LTC3856EFE#TRPBF?
For technical support, including LTC3856EFE#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3856EFE#TRPBF requirements.
6.How does Aetrix verify that LTC3856EFE#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3856EFE#TRPBF 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 LTC3856EFE#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3856EFE#TRPBF?
All LTC3856EFE#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3856EFE#TRPBF, 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 LTC3856EFE#TRPBF part is unused and in its original packaging.
Return procedure for LTC3856EFE#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3856EFE#TRPBF 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…
