My Inquiry
My Account
Analog Devices Inc. LTC3865EFE#PBF
- Part No.:
- LTC3865EFE#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 38-TFSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LTC3865EFE#PBF.pdf
- Description:
- IC REG CTRLR BUCK 38TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:100
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3865EFE#PBF from Analog Devices (formerly Linear Technology) is a dual, 2-phase synchronous step-down DC/DC controller driving all-N-channel MOSFET stages. It delivers precise dual-output regulation (e.g., 1.5V/15A and 1.2V/15A), supports 4.5V–38V input, operates up to 770kHz with phase-lock capability, and enables independent tracking/soft-start for each channel - used in high-density server VRMs and telecom power distribution systems.
For engineers reviewing the LTC3865EFE#PBF datasheet, LTC3865EFE#PBF pinout, LTC3865EFE#PBF application, or LTC3865EFE#PBF equivalent, key selection considerations include its 38-lead TSSOP package, dual 180°-phased operation, VID-based output programming, RSENSE/DCR current sensing, and selectable operating modes (Burst Mode®, pulse-skipping, continuous conduction).
Technical Context
The LTC3865EFE#PBF implements constant-frequency current-mode control with two independent 180°-out-of-phase channels, each featuring an error amplifier with OPTI-LOOP® compensation and programmable ITH threshold. Its MODE/PLLIN pin selects among Burst Mode®, pulse-skipping, or forced continuous conduction while enabling external synchronization via PLL input.
It supports wide VIN (4.5V–38V), integrates dual N-channel gate drivers (TG/BG) with matched rise/fall times (25ns), provides adjustable current limit via ILIM pin, and includes independent VOSENSE feedback inputs, TK/SS pins for tracking/soft-start, and separate PGOOD1/PGOOD2 open-drain outputs - all optimized for high-efficiency, low-noise dual-rail power delivery.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Topology | Dual synchronous buck controller with 180° phase shift - reduces input/output ripple and improves thermal distribution. |
| Input Voltage Range | 4.5V to 38V - supports 5V, 12V, 24V, and 28V intermediate bus architectures. |
| Switching Frequency | 250kHz to 770kHz (phase-lockable) - enables optimization of efficiency vs. size using standard magnetics. |
| Output Voltage Programming | Pin-strappable via 4 VID pins per channel (0.6V–5.0V range) - eliminates need for external DAC or digital interface. |
| Current Sensing | RSENSE or DCR - allows flexible trade-off between accuracy, power loss, and board area. |
| Operating Temperature | –40°C to +125°C junction - qualified for industrial and telecom base station environments. |
| Package | 38-lead plastic TSSOP with exposed pad - provides enhanced thermal performance (θJA = 25°C/W). |
Pinout & Package
Package: 38-Lead Plastic TSSOP (FE package), thermally enhanced with exposed SGND pad (Pin 39) requiring PCB soldering for optimal thermal and electrical performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RUN1, RUN2 (Pins 1, 17) | Independent enable inputs | Each channel disabled when pulled below 1.22V; internal 1μA pull-up enables standalone startup sequencing. |
| TK/SS1, TK/SS2 (Pins 6, 12) | Tracking/Soft-Start control | Internal 1.3μA current charges external capacitor to ramp VOUT linearly; supports master-slave voltage tracking. |
| VID11–VID22 (Pins 9, 10, 18, 37) | Output voltage configuration | Four binary-select pins per channel set nominal VOUT from 0.6V to 5.0V without external resistors. |
| PGOOD1, PGOOD2 (Pins 21, 20) | Channel-specific power-good indicators | Open-drain outputs assert low if corresponding VOUT deviates >±10% after 20μs blanking - enables independent rail monitoring. |
| MODE/PLLIN (Pin 36) | Operating mode & sync input | Selects Burst Mode® (float), pulse-skip (INTVCC), or forced CCM (SGND); accepts external clock for synchronization. |
| FREQ (Pin 38) | Oscillator frequency setting | 7.5μA sink current into external resistor sets switching frequency from 250kHz to 770kHz. |
| ILIM (Pin 19) | Current sense threshold select | Tie to SGND/FLOAT/INTVCC to configure max sense voltage (24/50/75mV) - adjusts current limit without changing RSENSE. |
| SENSE1±, SENSE2± (Pins 2, 3, 15, 16) | Differential current sense inputs | Accepts Kelvin-connected RSENSE or DCR network - rejects common-mode noise for stable light-load operation. |
| TG1/TG2, BG1/BG2 (Pins 34, 23, 31, 27) | N-channel gate drivers | Matched 2.6Ω pull-up / 1.5Ω pull-down drive strength ensures fast, shoot-through-free switching at high dV/dt. |
| VOSENSE1, VOSENSE2 (Pins 5, 13) | Feedback voltage inputs | Direct connection to output or external divider - enables remote sensing for tight regulation under load transients. |
Key Features
| Feature | Design Value |
|---|---|
| OPTI-LOOP® compensation | Allows stable loop response across wide range of output capacitance (10μF–1000μF) and ESR (0.5mΩ–50mΩ) without redesign. |
| Dual 180°-phased operation | Halves input RMS current and output voltage ripple vs. single-phase design - reduces bulk capacitor count and size. |
| Independent track/soft-start | Enables controlled power-up sequencing (e.g., core before I/O) or synchronized ramping of multiple rails from one reference. |
| Adjustable current foldback | Reduces MOSFET stress during short-circuit by lowering peak current limit - extends safe operating time before shutdown. |
| Output overvoltage protection | Disables top FET and limits reverse current if VOSENSE exceeds regulated value by >7% - prevents damage to downstream loads. |
Applications
| Server VRM | Telecom Intermediate Bus Converter |
|---|---|
Use Scenario: Dual-rail CPU/GPU core and I/O supply in 1U rack servers with strict thermal and transient response requirements. IC Role / Device Role / Timing Role: Dual-phase synchronous buck controller managing 1.2V/15A and 1.8V/10A rails with interleaved timing to minimize input ripple and improve thermal spreading. Use Value: Achieves >94% peak efficiency at full load and maintains <1% output deviation during 10A/μs load steps - meets Intel VR13/VR14 specifications. | Use Scenario: 48V-to-12V/24V conversion in wireless base station power shelves with high reliability and low standby loss. IC Role / Device Role / Timing Role: Primary controller regulating intermediate bus voltage with Burst Mode® operation to maintain <100μA quiescent current at no load. Use Value: Enables >92% efficiency at 20% load and supports phase-lock to system clock for EMI reduction - simplifies compliance testing. |
| Industrial PLC Power Module | High-Density FPGA Power Supply |
Use Scenario: Compact 24V-input power module delivering isolated 5V, 3.3V, and 1.2V rails for programmable logic controllers in harsh environments. IC Role / Device Role / Timing Role: Dual-channel controller generating 5V/3A and 3.3V/5A with independent soft-start and PGOOD monitoring for fault isolation. Use Value: Wide –40°C to +125°C operating range and robust UVLO/OLP ensure reliable cold-start and brownout recovery - meets IEC 61000-4-2/4-4 immunity. | Use Scenario: Multi-rail supply for Xilinx Kintex UltraScale+ FPGA with dynamic voltage scaling and rail sequencing requirements. IC Role / Device Role / Timing Role: Dual controller implementing precise voltage tracking (1.2V core and 0.85V auxiliary) using TK/SS pin coupling and VID strapping. Use Value: Sub-10mV tracking error and <50μs response to 50% load step meet Xilinx DS925 spec - eliminates need for external sequencer IC. |
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 |
|---|---|---|---|
| MP8765GL-DS | Single-chip dual-phase controller with integrated 40V/5A MOSFETs; fixed 500kHz frequency; no VID programming. | Targeted at space-constrained consumer/industrial SMPS where board area > flexibility; lacks phase-lock and external sync. | Choose MP8765GL-DS for cost-sensitive, lower-current (<8A/rail) designs where integration reduces BOM count. |
| ISL95836IRZ | Intel VR12.5-compliant dual-phase controller; supports SVID interface; higher pin count (48-QFN); no TSSOP option. | Designed specifically for mobile CPU VRMs with dynamic VID updates; requires SVID host controller. | Choose ISL95836IRZ only when SVID protocol and Intel compliance are mandatory - not suitable for standalone analog control. |
Compared with MP8765GL-DS and ISL95836IRZ, the LTC3865EFE#PBF offers unmatched analog configurability (VID, FREQ, ILIM, MODE/PLLIN), industry-leading thermal performance in TSSOP, and seamless migration from discrete MOSFET designs - making it ideal for high-reliability, multi-rail industrial and telecom systems.
Availability
LTC3865EFE#PBF is available at Aetrix Electronics and suitable for server VRMs, telecom intermediate bus converters, and industrial PLC power modules requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LTC3865EFE#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 semiconductors, acquired Linear Technology in 2017 to strengthen its power management portfolio.
The LTC3865EFE#PBF belongs to ADI's high-efficiency DC/DC controller product line, designed specifically for demanding multi-rail, high-current power delivery in datacenter, communications, and industrial infrastructure equipment.
FAQ
What is the maximum supported switching frequency for the LTC3865EFE#PBF?
The LTC3865EFE#PBF supports a phase-lockable switching frequency range from 250kHz to 770kHz. The upper limit of 770kHz is achieved when the FREQ pin is biased with a ≥325kΩ resistor. This high-frequency capability allows use of smaller inductors and capacitors while maintaining excellent transient response - critical for modern high-speed digital loads powered by the LTC3865EFE#PBF.
Does the LTC3865EFE#PBF support both RSENSE and DCR current sensing?
Yes, the LTC3865EFE#PBF supports both RSENSE and DCR current sensing via its differential SENSE1± and SENSE2± inputs. The device includes built-in slope compensation and reverse-current detection (IREV) to ensure stability and prevent negative inductor current in DCR configurations. This dual-sensing flexibility lets designers optimize for accuracy (RSENSE) or efficiency (DCR) depending on the application requirements of the LTC3865EFE#PBF.
How does the ILIM pin affect current limiting on the LTC3865EFE#PBF?
The ILIM pin on the LTC3865EFE#PBF selects the maximum current sense threshold: tying ILIM to SGND sets it to 24mV, floating sets it to 50mV, and tying to INTVCC sets it to 75mV (E-grade). This directly scales the peak inductor current limit without changing external components - enabling rapid current-limit tuning during validation or across product variants using the same LTC3865EFE#PBF design.
Can the LTC3865EFE#PBF operate with only one channel enabled?
Yes, the LTC3865EFE#PBF supports independent channel control via RUN1 and RUN2 pins. Pulling either pin below 1.22V disables its respective controller while leaving the other fully operational - allowing asymmetric rail generation (e.g., 1.2V active, 3.3V standby). Both channels share internal references and biasing, so single-channel operation maintains full accuracy and regulation integrity for the enabled LTC3865EFE#PBF channel.
What is the purpose of the EXTVCC pin on the LTC3865EFE#PBF?
The EXTVCC pin on the LTC3865EFE#PBF allows bypassing the internal 5V LDO regulator by supplying an external 4.7V–6V source. When EXTVCC exceeds 4.7V, an internal switch connects it directly to INTVCC, reducing power loss and heat generation - especially beneficial in high-input-voltage applications where the LDO would otherwise dissipate significant power. This feature improves overall system efficiency when powering the LTC3865EFE#PBF from a pre-regulated rail.
LTC3865EFE#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 38-TFSOP (0.173", 4.40mm Width) 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 ~ 770kHz
- Duty Cycle (Max):
- 95%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable, Frequency 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
LTC3865EFE#PBF FAQ
1.How can I place an order for LTC3865EFE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3865EFE#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 LTC3865EFE#PBF reliable?
The price and inventory of LTC3865EFE#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3865EFE#PBF is usually 5 days.
3.What payment methods are accepted for LTC3865EFE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3865EFE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3865EFE#PBF?
LTC3865EFE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3865EFE#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 LTC3865EFE#PBF?
For technical support, including LTC3865EFE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3865EFE#PBF requirements.
6.How does Aetrix verify that LTC3865EFE#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3865EFE#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 LTC3865EFE#PBF meets industry standards.
7.What is the process for return or replacement of LTC3865EFE#PBF?
All LTC3865EFE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3865EFE#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 LTC3865EFE#PBF part is unused and in its original packaging.
Return procedure for LTC3865EFE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3865EFE#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…
