My Inquiry
My Account
Analog Devices Inc. LTC3858EUH-2#TRPBF
- Part No.:
- LTC3858EUH-2#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 32-WFQFN Exposed Pad
- Datasheet:
-
LTC3858EUH-2#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,864
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3858EUH-2#TRPBF from Analog Devices (formerly Linear Technology) is a dual-phase, synchronous step-down DC/DC controller IC driving two independent N-channel MOSFET stages. It delivers 0.8V–24V output voltage across 4V–38V input, supports out-of-phase operation to reduce input ripple, features 170μA no-load quiescent current, and operates up to 850kHz with phase-lock capability - enabling high-efficiency 3.3V/8.5V dual-rail power for battery-powered digital systems.
For engineers reviewing the LTC3858EUH-2#TRPBF datasheet, LTC3858EUH-2#TRPBF pinout, LTC3858EUH-2#TRPBF application, or LTC3858EUH-2#TRPBF equivalent, key selection criteria include its dual-channel current-mode architecture, OPTI-LOOP® compensation, selectable light-load modes (Burst Mode®, pulse-skipping, forced continuous), and 5mm × 5mm QFN-32 package with exposed thermal pad.
Technical Context
The LTC3858EUH-2#TRPBF implements a constant-frequency current-mode control architecture with two independent controllers operating 180° out of phase. Each channel uses an error amplifier (EA) comparing VFB to a 0.800V reference, with ITH pin voltage setting peak inductor current via differential current sensing at SENSE+ and SENSE− pins.
It integrates dual gate drivers (TG/BG) with 2.5Ω pull-up and 1.5Ω pull-down on TG, supports RSENSE or DCR sensing, includes programmable frequency (50–900kHz) via FREQ pin, and disables overvoltage crowbar and short-circuit latchoff - distinguishing it from LTC3858 and LTC3858-1 variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 4V to 38V - supports wide-input industrial, automotive, and battery-based intermediate bus applications. |
| VOUT Range | 0.8V to 24V - enables flexible dual-rail generation including 3.3V, 5V, 8.5V, and 12V outputs. |
| IQ (One Channel On) | 170μA - extends runtime in battery-operated systems by minimizing no-load power loss. |
| fSYNC | 75kHz to 850kHz - allows EMI optimization and input capacitor reduction via external clock synchronization. |
| Duty Cycle Max | 99% - enables ultra-low dropout operation when VIN approaches VOUT, critical for high-efficiency near-rail regulation. |
| Feedback Voltage | 0.800V ±12mV - precise reference ensures tight output regulation across temperature and load. |
| Shutdown IQ | 8μA - facilitates deep power-down for system-level energy management. |
Pinout & Package
Package: 32-lead (5mm × 5mm) plastic QFN with exposed thermal pad (Pin 33 = SGND), rated for –40°C to 125°C junction temperature. Exposed pad must be soldered to PCB for thermal performance (θJA = 34°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SENSE1−, SENSE2− (1, 9) | Differential current sense (−) inputs | Accept common-mode voltages up to INTVCC − 0.5V; bias current ±1μA enables accurate DCR/RSENSE sensing. |
| FREQ (2) | Oscillator frequency programming | 20μA internal pull-up sets VCO frequency; resistor-to-GND selects 50–900kHz; GND/INTVCC forces fixed 350/535kHz. |
| PLLIN/MODE (5) | Sync input & light-load mode control | Accepts external clock (75–850kHz) or DC voltage: GND = Burst Mode®, INTVCC = forced continuous, 1.2–(INTVCC−1.3)V = pulse-skipping. |
| SGND (6, 33) | Small-signal ground reference | Must be routed separately from PGND; exposed pad (Pin 33) is SGND and requires solid thermal connection to PCB. |
| RUN1, RUN2 (7, 8) | Independent channel enable | Below 1.26V shuts down respective channel; both <0.7V enables 8μA shutdown mode. |
| TG1, TG2 (15, 26) | Top N-MOSFET gate drivers | Floating drivers with ~2.5Ω pull-up; voltage swing = INTVCC − 0.5V superimposed on SW node. |
| PGOOD1, PGOOD2 (14, 27) | Open-drain output voltage monitors | Assert low when VFB deviates >±10% from 0.8V; includes 2.5% hysteresis for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| OPTI-LOOP® Compensation | Enables stable transient response across wide range of output capacitance (e.g., 22μF–150μF) and ESR without loop redesign. |
| Out-of-Phase Dual Control | Reduces RMS input ripple current by ~70% vs in-phase operation, allowing smaller input capacitors and lower ESR stress. |
| Selectably Programmable Light-Load Modes | Burst Mode® (170μA IQ), pulse-skipping, or forced continuous - lets designers optimize efficiency vs output ripple trade-off per application. |
| Independent Soft-Start / Tracking (SS1, SS2) | Internal 1μA pull-up + external capacitor enables linear ramp; resistor divider enables precise voltage tracking during power-up sequences. |
| Integrated INTVCC LDO with EXTVCC Switchover | 5.1V ±3% regulated supply powers gate drivers; automatic switchover to EXTVCC ≥4.7V improves efficiency when powered from local rail. |
Applications
| Industrial Embedded Power | Automotive Infotainment |
|---|---|
|
Use Scenario: Dual-rail power for FPGA + microcontroller subsystems in programmable logic controllers (PLCs) requiring stable 3.3V core and 8.5V I/O rails. IC Role / Device Role / Timing Role: Dual-phase synchronous buck controller managing independent output regulation, sequencing, and fault monitoring. Use Value: 170μA quiescent current extends battery backup duration; out-of-phase operation reduces input capacitor count by 40% versus single-phase designs. |
Use Scenario: Powering display interface and audio DSP in vehicle head units with 12V battery input and strict EMI limits. IC Role / Device Role / Timing Role: Phase-locked dual controller synchronizing switching to system clock to suppress conducted emissions in narrow bands. Use Value: 75–850kHz sync range enables EMI avoidance; Burst Mode® maintains >85% efficiency at 10mA load, critical for always-on functions. |
| Portable Medical Instrumentation | Distributed Telecom Power |
|
Use Scenario: Battery-powered ultrasound handheld with dual analog front-end (2.5V) and digital processing (1.2V) rails requiring low-noise, long-life power. IC Role / Device Role / Timing Role: Dual-channel controller with independent soft-start and PGOOD monitoring ensuring safe, sequenced power-up of sensitive analog circuitry. Use Value: Adjustable current limit (ILIM pin) prevents MOSFET overstress during probe insertion transients; 99% duty cycle supports 3.6V Li-ion input down to 3.3V output. |
Use Scenario: Intermediate bus conversion in 48V telecom systems feeding point-of-load regulators for baseband processors and RF modules. IC Role / Device Role / Timing Role: High-vin dual controller delivering 5V/12V rails with phase interleaving to minimize bulk capacitor size and thermal footprint. Use Value: 4V–38V input range accommodates 48V nominal with 20% sag; RSENSE/DCR flexibility simplifies current sensing in high-current (>10A) designs. |
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 |
|---|---|---|---|
| LTC3858IUH-2#TRPBF | Same silicon, rated for full –40°C to 125°C operating junction temperature (vs E-grade's 0°C to 85°C guaranteed spec). | Required for extended-temperature industrial or under-hood automotive use where ambient exceeds 85°C. | Select when full temperature range validation is mandated; identical pinout, layout, and firmware compatibility. |
| MP2918GL-Z | Monolithic dual buck (integrated MOSFETs); 4.5–18V VIN; fixed 0.6V reference; no PLL sync or OPTI-LOOP. | Suitable for space-constrained, lower-power (<10A/channel) applications where integration outweighs flexibility. | Choose for simplified BOM and layout when input voltage ≤18V and design does not require phase sync or ultra-low IQ. |
Compared with LTC3858IUH-2#TRPBF, the LTC3858EUH-2#TRPBF offers identical functionality but with production-tested specs only to 85°C ambient - making it cost-optimized for commercial-temperature applications. Versus MP2918GL-Z, it trades monolithic integration for higher VIN, programmable topology, and superior light-load efficiency control.
Availability
LTC3858EUH-2#TRPBF is available at Aetrix Electronics and suitable for industrial embedded power, automotive infotainment, and portable medical instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LTC3858EUH-2#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 its high-performance power management portfolio, emphasizing precision, efficiency, and reliability in analog and mixed-signal ICs.
The LTC3858EUH-2#TRPBF belongs to Linear's PolyPhase® controller family, designed specifically for high-efficiency, multi-phase DC/DC conversion in space- and thermally-constrained systems where low quiescent current and flexible light-load operation are critical.
FAQ
What is the primary function of the LTC3858EUH-2#TRPBF?
The LTC3858EUH-2#TRPBF is a dual-phase, synchronous step-down DC/DC controller IC that drives external N-channel MOSFETs to generate two independently regulated output voltages. Its core function is high-efficiency power conversion across a wide input range (4V–38V), with features like out-of-phase operation, OPTI-LOOP® compensation, and selectable light-load modes - all implemented in the LTC3858EUH-2#TRPBF's 5mm × 5mm QFN package.
How does the LTC3858EUH-2#TRPBF achieve ultra-low quiescent current?
The LTC3858EUH-2#TRPBF achieves 170μA quiescent current (one channel active) through integrated sleep-mode circuitry triggered when ITH drops below 0.425V. In this state, internal bias currents and non-essential blocks are disabled while retaining feedback monitoring. The LTC3858EUH-2#TRPBF also features an 8μA shutdown mode when both RUN pins fall below 0.7V - critical for battery longevity in always-on systems.
Can the LTC3858EUH-2#TRPBF synchronize to an external clock?
Yes, the LTC3858EUH-2#TRPBF supports external synchronization via the PLLIN/MODE pin. When an external clock (75kHz–850kHz) is applied, its internal phase-locked loop aligns the rising edge of TG1 with the external clock's rising edge. This capability is documented in the LTC3858EUH-2#TRPBF datasheet Figure 1 and enables EMI reduction and multi-controller coordination without requiring additional timing components.
What is the purpose of the ILIM pin on the LTC3858EUH-2#TRPBF?
The ILIM pin on the LTC3858EUH-2#TRPBF selects one of three maximum current sense threshold levels (22mV, 43mV, or 64mV) for both current comparators. Tying ILIM to SGND, FLOAT, or INTVCC configures the trip point to match different RSENSE values or DCR networks - enabling consistent current limiting across varying inductor or sense resistor selections in the LTC3858EUH-2#TRPBF application circuit.
Does the LTC3858EUH-2#TRPBF support output voltage tracking during startup?
Yes, the LTC3858EUH-2#TRPBF supports precise output voltage tracking using the SS1 and SS2 pins. By connecting an external resistor divider from a master supply to SGND and routing it to SS1 or SS2, the LTC3858EUH-2#TRPBF regulates its VFB pin to follow the divider voltage - ensuring controlled, monotonic startup sequencing between multiple rails without external supervisors.
LTC3858EUH-2#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- PolyPhase®
- Package/Case:
- 32-WFQFN 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):
- 4V ~ 38V
- Frequency - Switching:
- 105kHz ~ 835kHz, 350kHz ~ 535kHz
- Duty Cycle (Max):
- 99%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable, Frequency Control, Phase Control, Power Good, Soft Start
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-QFN (5x5)
LTC3858EUH-2#TRPBF FAQ
1.How can I place an order for LTC3858EUH-2#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3858EUH-2#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 LTC3858EUH-2#TRPBF reliable?
The price and inventory of LTC3858EUH-2#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3858EUH-2#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3858EUH-2#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3858EUH-2#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3858EUH-2#TRPBF?
LTC3858EUH-2#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3858EUH-2#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 LTC3858EUH-2#TRPBF?
For technical support, including LTC3858EUH-2#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3858EUH-2#TRPBF requirements.
6.How does Aetrix verify that LTC3858EUH-2#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3858EUH-2#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 LTC3858EUH-2#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3858EUH-2#TRPBF?
All LTC3858EUH-2#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3858EUH-2#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 LTC3858EUH-2#TRPBF part is unused and in its original packaging.
Return procedure for LTC3858EUH-2#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3858EUH-2#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…
