My Inquiry
My Account
Analog Devices Inc. LTC3859AEFE#TRPBF
- Part No.:
- LTC3859AEFE#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 38-TFSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LTC3859AEFE#TRPBF.pdf
- Description:
- IC REG CTRLR MULT TOP 38TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,945
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3859AEFE#TRPBF from Analog Devices is a triple-output synchronous DC/DC controller (buck/buck/boost) driving all-N-channel MOSFET stages, featuring 55μA no-load quiescent current, 0.8V/1.2V precision references for buck/boost outputs, and phase-lockable switching frequency up to 850kHz. It supports cold-crank operation down to 2.5V input after startup and delivers regulated outputs in automotive start-stop and battery-powered digital systems.
For engineers reviewing the LTC3859AEFE#TRPBF datasheet, LTC3859AEFE#TRPBF pinout, LTC3859AEFE#TRPBF application, or LTC3859AEFE#TRPBF equivalent, key selection criteria include its triple-output topology with independent RUN control, OPTI-LOOP compensation for wide output capacitor/ESR tolerance, Burst Mode® optimization for high-input-voltage boost regulation, and TSSOP-38 package compatibility with thermal pad grounding requirements.
Technical Context
The LTC3859AEFE#TRPBF integrates three independent current-mode controllers: two buck channels with 0.8V reference and 99% max duty cycle dropout capability, and one boost channel with 1.2V reference, 100% synchronous duty cycle support, and improved Burst Mode performance when VIN > VOUT. Its PLLIN/MODE pin selects among Burst Mode, pulse-skipping, or forced continuous conduction across all channels.
It features dual gate drivers per channel (TG/BG) with sub-30ns transition times, RSENSE or DCR current sensing, and separate SENSE+/- inputs with ±1µA bias currents. The INTVCC LDO (5.4V typical) powers internal circuitry and supports EXTVCC switchover at 4.7V, while SGND and PGND are isolated for noise-sensitive feedback routing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Topology | Buck/Buck/Boost triple-output synchronous controller - enables single-chip multi-rail power for mixed-voltage SoCs or automotive ECUs. |
| Input Voltage Range | 4.5V–38V main bias; operates down to 2.5V after startup when biased from boost output - supports cold-crank and wide automotive input transients. |
| Quiescent Current | 55μA in Sleep Mode (one channel active) - extends runtime in always-on battery systems like telematics or ADAS sensors. |
| Feedback References | 0.8V ±12mV (buck), 1.2V ±12mV (boost) - enables precise output regulation across temperature and load for stable logic/core/IO rails. |
| Switching Frequency | 75kHz–850kHz phase-lockable; programmable 50kHz–900kHz via FREQ resistor - allows EMI tuning and inductor size optimization. |
| Gate Drive Strength | TG/BG pull-up: 1.2Ω (boost), 2.5Ω (buck); rise/fall <30ns @3.3nF - ensures fast MOSFET switching with low conduction loss in high-current designs. |
| Protection Features | PGOOD1 (buck1), OV3 (boost overvoltage), undervoltage lockout (4.15V rising), shutdown IQ = 14μA - provides system-level fault signaling and safe power sequencing. |
Pinout & Package
Package: 38-pin plastic TSSOP (FE) with exposed PGND pad (Pin 39), 5mm × 7mm footprint, θJA = 25°C/W. Requires soldering of exposed pad to PCB ground plane for thermal and electrical performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RUN1, RUN2, RUN3 (Pins 9,10,11) | Digital enable inputs per channel | Independent shutdown control: <1.17V (buck) or <1.20V (boost) disables respective regulator; all <0.7V enters full shutdown (14μA). |
| VFB1, VFB2, VFB3 (Pins 36,14,6) | Feedback voltage inputs | Monitor output via resistive divider; regulate to 0.8V (buck) or 1.2V (boost); PGOOD1 asserts only when VFB1 is within ±10%. |
| SENSE1+/−, SENSE2+/−, SENSE3+/− (Pins 37/38,13/12,4/5) | Differential current sense inputs | Measure inductor current via RSENSE or DCR; SENSE3+ sources 170μA; buck SENSE− supplies current when VOUT > INTVCC + 0.5V. |
| TG1/TG2/TG3, BG1/BG2/BG3 (Pins 32/29,18/21,27/25) | N-channel MOSFET gate drivers | TG drives high-side switch with floating bootstrap supply (BOOSTx); BG drives low-side switch referenced to PGND. |
| PLLIN/MODE (Pin 2) | Mode selection & sync input | Pull to GND → Burst Mode; tie to INTVCC → forced CCM; apply external clock → phase-locked operation with synchronized TG1 rising edge. |
| PGOOD1 (Pin 33), OV3 (Pin 17) | Open-drain status outputs | PGOOD1 indicates buck1 regulation (±10%); OV3 asserts low when boost output exceeds 110% setpoint - enables system fault monitoring. |
Key Features
| Feature | Design Value |
|---|---|
| OPTI-LOOP compensation | Allows stable loop response across wide range of output capacitance (ceramic/tantalum) and ESR values without external compensation redesign. |
| Triple independent RUN control | Enables staggered power-up, dynamic rail disabling, and partial-system sleep modes - critical for low-power automotive microcontrollers. |
| 100% duty cycle support in Boost | Maintains regulation even during input voltage collapse (e.g., engine cranking), eliminating need for external linear post-regulators. |
| Low-IQ Burst Mode® enhancement | Reduces light-load boost converter ripple and improves efficiency when VIN > VOUT - specifically optimized vs. LTC3859 baseline. |
| Separate SGND and PGND | Minimizes noise coupling between sensitive analog feedback paths and high-current switching nodes - improves regulation accuracy and EMI. |
Applications
| Automotive Start-Stop ECU | Industrial IoT Sensor Hub |
|---|---|
Use Scenario: Powering MCU, CAN transceiver, and analog sensor rails in engine bay under cold-crank (4.5V–2.5V transient) and stop-start cycling. IC Role / Device Role / Timing Role: Triple-output controller generating 5V (MCU), 8.5V (CAN), and 10V (sensor bias) with independent RUN sequencing and cold-crank hold-up. Use Value: 55μA Sleep IQ extends battery life during vehicle off-state; 2.5V start-up capability maintains regulation through 12V battery sag below 6V. |
Use Scenario: Distributed power for LPWAN node with ARM Cortex-M, LoRa radio, and environmental sensors operating on primary Li-SOCl₂ cell. IC Role / Device Role / Timing Role: Buck/buck/boost topology generates 3.3V (MCU), 3.6V (radio), and 5V (sensor bias) from 3.0V–3.6V nominal input. Use Value: Burst Mode operation achieves >85% efficiency at 100μA load; OPTI-LOOP accommodates aging electrolytic bulk capacitors without loop instability. |
| Multi-Rail FPGA Development Board | Medical Portable Diagnostic Device |
Use Scenario: Providing core (0.85V), I/O (1.8V), and auxiliary (3.3V) rails for Xilinx Artix-7 FPGA with dynamic voltage scaling and thermal throttling. IC Role / Device Role / Timing Role: Dual buck channels deliver core/I/O rails; boost channel supplies 3.3V from 2.5V auxiliary source during low-power mode. Use Value: Independent TRACK/SS pins enable synchronized soft-start and voltage tracking; 99% buck dropout prevents brownout during high di/dt events. |
Use Scenario: Battery-powered ultrasound probe requiring isolated analog front-end (±5V), digital logic (1.2V/3.3V), and display backlight (24V) from single 7.4V Li-ion pack. IC Role / Device Role / Timing Role: Buck/buck/boost controller generates 3.3V (digital), 1.2V (FPGA core), and 24V (backlight) with PGOOD1 and OV3 fault reporting. Use Value: 60V boost capability eliminates need for external boost IC; 14μA shutdown IQ meets IEC 62304 standby power limits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar triple-output synchronous controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3859IFE#TRPBF | Same silicon, rated for –40°C to 125°C junction temperature (vs. LTC3859AEFE#TRPBF's –40°C to 125°C grade); identical electrical specs and pinout. | No functional difference; selected for same automotive/industrial applications where extended temp validation is required. | Choose LTC3859IFE#TRPBF if AEC-Q100 qualification or extended production test coverage is mandated. |
| LTC3859AEUHF#TRPBF | Same functionality in 5mm × 7mm QFN package (UHF), θJA = 34.7°C/W vs. TSSOP's 25°C/W; identical electrical specs and pin mapping. | Better thermal performance in high-density layouts; requires different PCB footprint and reflow profile than TSSOP. | Choose LTC3859AEUHF#TRPBF for space-constrained designs needing lower thermal resistance and improved power density. |
Compared with LTC3859IFE#TRPBF, the LTC3859AEFE#TRPBF offers identical performance in TSSOP packaging optimized for manual inspection and legacy assembly lines; versus LTC3859AEUHF#TRPBF, it trades higher thermal resistance for easier solderability and lower cost in medium-volume production.
Availability
LTC3859AEFE#TRPBF is available at Aetrix Electronics and suitable for automotive start-stop systems, battery-operated medical devices, and industrial IoT sensor hubs requiring stable component supply with long lifecycle support and traceable sourcing.
Supply support for LTC3859AEFE#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.
The LTC3859A product line delivers high-efficiency, low-quiescent-current multi-output controllers for demanding power architectures in automotive and portable electronics - designed to replace discrete solutions with integrated timing, protection, and sequencing.
FAQ
What is the minimum input voltage required for startup of the LTC3859AEFE#TRPBF?
The LTC3859AEFE#TRPBF requires a minimum 5V on VBIAS to initiate startup. Once running, it can sustain operation down to 2.5V input when biased from the boost output or an auxiliary supply - enabling cold-crank support in automotive applications where battery voltage dips below 6V during engine cranking.
How does the PLLIN/MODE pin configure light-load operation for the LTC3859AEFE#TRPBF?
The PLLIN/MODE pin configures light-load behavior across all three channels: grounded or floating (via internal 100kΩ pull-down) enables Burst Mode®; tied to INTVCC forces continuous conduction; biased to 1.2V–(INTVCC–1.3V) selects pulse-skipping. This single pin synchronizes mode selection without per-channel configuration overhead.
Can the LTC3859AEFE#TRPBF drive both N-channel and P-channel MOSFETs in its boost stage?
No - the LTC3859AEFE#TRPBF is designed exclusively for all-N-channel MOSFET topologies. Its TG3 and BG3 drivers provide floating high-side and ground-referenced low-side gate drive compatible only with N-channel devices; external level-shifting or P-channel use is not supported.
What is the purpose of the exposed pad (Pin 39) on the LTC3859AEFE#TRPBF TSSOP package?
The exposed pad (Pin 39) is electrically and thermally connected to PGND. It must be soldered to a PCB copper pour tied to the power ground plane to ensure proper thermal dissipation (θJA = 25°C/W) and low-impedance return path for high-current gate drive and switch-node currents - omission causes thermal runaway and regulation failure.
Does the LTC3859AEFE#TRPBF support output voltage tracking during startup?
Yes - the TRACK/SS1 and TRACK/SS2 pins enable voltage tracking for buck outputs by connecting them to a reference voltage ramp (e.g., from another regulator's soft-start pin); SS3 controls boost soft-start independently. Internal 1µA current sources charge external capacitors to set ramp rates, ensuring monotonic, coordinated rail sequencing.
LTC3859AEFE#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- 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, Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck, Buck-Boost, SEPIC
- Number of Outputs:
- 3
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 4.5V ~ 38V
- Frequency - Switching:
- 115kHz ~ 835kHz, 350kHz ~ 535kHz
- Duty Cycle (Max):
- 99%, 100%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- 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
LTC3859AEFE#TRPBF FAQ
1.How can I place an order for LTC3859AEFE#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3859AEFE#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 LTC3859AEFE#TRPBF reliable?
The price and inventory of LTC3859AEFE#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3859AEFE#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3859AEFE#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3859AEFE#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3859AEFE#TRPBF?
LTC3859AEFE#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3859AEFE#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 LTC3859AEFE#TRPBF?
For technical support, including LTC3859AEFE#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3859AEFE#TRPBF requirements.
6.How does Aetrix verify that LTC3859AEFE#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3859AEFE#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 LTC3859AEFE#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3859AEFE#TRPBF?
All LTC3859AEFE#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3859AEFE#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 LTC3859AEFE#TRPBF part is unused and in its original packaging.
Return procedure for LTC3859AEFE#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3859AEFE#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…
