My Inquiry
My Account
Analog Devices Inc. LTC3857EGN-1#TRPBF
- Part No.:
- LTC3857EGN-1#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 28-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
LTC3857EGN-1#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK 28SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,660
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3857EGN-1#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 for high-efficiency 3.3V/8.5V power rails. It features 50μA quiescent current in single-channel sleep mode, 4V–38V input range, and 0.8V–24V programmable output voltage per channel - enabling use in automotive always-on systems and battery-powered digital devices.
For engineers reviewing the LTC3857EGN-1#TRPBF datasheet, LTC3857EGN-1#TRPBF pinout, LTC3857EGN-1#TRPBF application, or LTC3857EGN-1#TRPBF equivalent, key selection criteria include out-of-phase dual-channel operation to reduce input capacitance, OPTI-LOOP® compensation for minimal output capacitance, selectable light-load modes (Burst Mode®, pulse-skipping, or forced continuous), and phase-lockable frequency up to 850kHz.
Technical Context
The LTC3857EGN-1#TRPBF implements a constant-frequency current-mode architecture with two 180° out-of-phase controllers, minimizing input ripple and ESR-related losses. Each channel uses independent error amplifiers (ITH1/ITH2), differential current sensing (SENSE1±/SENSE2±), and precision 0.800V feedback reference with ±10mV tolerance over temperature.
It integrates dual gate drivers (TG1/BG1 and TG2/BG2) with 2.5Ω pull-up / 1.5Ω pull-down on top-side and 2.4Ω/1.1Ω on bottom-side drivers, supports RSENSE or DCR current sensing, and includes dedicated TRACK/SS pins for independent soft-start or voltage tracking - all within a thermally enhanced 28-lead SSOP package rated for –40°C to 125°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4V to 38V - supports wide intermediate bus voltages and battery chemistries including 12V automotive and 24V industrial rails. |
| Quiescent Current (Sleep Mode) | 50μA (one channel active) - extends runtime in battery-operated systems without compromising start-up responsiveness. |
| Feedback Reference Voltage | 0.800V ±10mV - enables precise output regulation across temperature and load, critical for low-voltage digital core supplies. |
| Switching Frequency Range | 75kHz–850kHz (phase-lockable) or 50kHz–900kHz (programmable) - balances efficiency vs. component size; 350kHz/535kHz fixed options simplify design. |
| Duty Cycle Max | 99.4% - ensures stable operation during deep dropout conditions (e.g., VIN = 5.5V → VOUT = 5V). |
| Current Sense Threshold | 43mV to 57mV - sets accurate overcurrent protection and current limit with minimal power loss in sense resistor or DCR network. |
| PGOOD Output Accuracy | ±10% trip threshold with 2.5% hysteresis - provides reliable power-good signaling for system sequencing and fault detection. |
Pinout & Package
Package: 28-lead plastic SSOP (GN), 5.3mm × 10.2mm, exposed pad for thermal enhancement, rated for –40°C to 125°C operating junction temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ITH1, ITH2 | Error amplifier outputs & compensation nodes | Set peak inductor current per channel; voltage directly controls current limit and loop stability via external RC network. |
| VFB1, VFB2 | Feedback inputs | Monitor regulated output via resistive divider; internal 0.800V reference enables accurate 3.3V, 5V, 8.5V, or custom rail generation. |
| SENSE1+, SENSE2+ | Current sense positive inputs | Connect to high-side of sense resistor or DCR network; differential measurement rejects common-mode noise. |
| SENSE1–, SENSE2– | Current sense negative inputs | Reference point for current comparator; bias current <±1μA minimizes offset errors in precision sensing. |
| TG1, TG2 / BG1, BG2 | Top/bottom gate drivers | Drive N-MOSFET gates with 2.5Ω/1.5Ω (TG) and 2.4Ω/1.1Ω (BG) on-resistance; support >5A per phase with fast rise/fall times (≤28ns). |
| TRACK/SS1, TRACK/SS2 | Soft-start & tracking control | Internal 1μA pull-up enables linear ramp-up; external resistor divider allows output voltage to track another supply during power-up. |
| PLLIN/MODE | Light-load mode & sync input | Selects Burst Mode® (GND), pulse-skipping (1.2V–INTVCC–1.3V), or forced continuous (INTVCC); accepts external clock for phase synchronization. |
| RUN1, RUN2 | Channel enable/disable | Digital control: <1.26V disables individual channel; <0.7V shuts down entire IC, reducing IQ to <8μA. |
| PGOOD1 | Power-good indicator | Open-drain output asserts low when VFB1 deviates >±10% from setpoint - used for system reset or sequencing logic. |
Key Features
| Feature | Design Value |
|---|---|
| Out-of-phase dual controllers | Reduces RMS input capacitor current by ~30%, allowing smaller bulk capacitance and lower EMI in distributed power systems. |
| OPTI-LOOP® compensation | Minimizes required output capacitance while maintaining stability across wide load and temperature ranges - reduces BOM cost and board area. |
| Programmable light-load operation | Three selectable modes (Burst, pulse-skipping, forced continuous) let designers optimize efficiency, ripple, and noise for specific application requirements. |
| Independent soft-start/tracking | Per-channel TRACK/SS pins enable staggered power-up sequencing or precise voltage ramping - essential for FPGA, ASIC, and multi-rail processors. |
| Robust gate drive architecture | Dual N-MOSFET drivers with integrated bootstrap circuitry and dropout detection ensure reliable high-side switching even at ultra-low VIN–VOUT differentials. |
Applications
| Automotive Infotainment Power Supply | Industrial PLC Dual-Rail System |
|---|---|
Use Scenario: Powering SoC, DDR memory, and display interfaces in vehicle head units with strict 12V battery input and low-quiescent-current requirements. IC Role / Device Role / Timing Role: Dual-phase controller generating isolated 3.3V (core logic) and 8.5V (display backlight) rails with independent soft-start and PGOOD monitoring. Use Value: 50μA sleep IQ extends battery life during vehicle off-state; out-of-phase operation suppresses conducted EMI to meet CISPR-25 Class 5 limits. | Use Scenario: Providing tightly regulated 3.3V and 8.5V supplies for programmable logic controllers operating from 24V industrial bus with wide ambient temperature variation. IC Role / Device Role / Timing Role: High-reliability dual buck controller with –40°C to 125°C operation, independent RUN pin control, and robust overvoltage protection. Use Value: 0.800V ±10mV reference and ±10% PGOOD accuracy ensure deterministic system boot and fault response under thermal stress. |
| Battery-Powered Test Equipment | Distributed Telecom DC Distribution |
Use Scenario: Portable oscilloscopes and signal analyzers requiring long runtime from Li-ion packs and clean, low-noise analog/digital supplies. IC Role / Device Role / Timing Role: Dual-channel controller delivering 3.3V (microcontroller/FPGA) and 8.5V (analog front-end op-amps) with selectable light-load mode. Use Value: Burst Mode® operation achieves >85% efficiency at 1mA load, preserving battery capacity without sacrificing transient response. | Use Scenario: Intermediate bus conversion in 48V telecom systems feeding multiple downstream point-of-load regulators. IC Role / Device Role / Timing Role: High-input-voltage dual controller stepping 48V down to 3.3V/8.5V intermediate rails with phase synchronization to avoid beat frequencies. Use Value: Phase-lockable 75kHz–850kHz frequency enables synchronized switching across multiple LTC3857EGN-1#TRPBF units, reducing system-level ripple and EMI. |
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 |
|---|---|---|---|
| MP2918GL-Z | Single-chip dual-phase controller with integrated MOSFET drivers but no EXTVCC option; max VIN = 28V; fixed 0.6V reference. | Suitable for space-constrained designs where integrated FETs are acceptable; not rated for 38V automotive transients. | Choose MP2918GL-Z when board area is critical and input voltage stays below 28V; retain LTC3857EGN-1#TRPBF for 38V tolerance and EXTVCC flexibility. |
| LTC3857IGN-1#TRPBF | Identical electrical specs and pinout; differs only in temperature grade (–40°C to 125°C industrial vs. extended commercial grade for GN variant). | No functional difference in operation; selected when full industrial temp qualification is required for production release. | Use LTC3857IGN-1#TRPBF for automotive or harsh-environment deployments; LTC3857EGN-1#TRPBF suffices for commercial-grade instrumentation. |
Compared with MP2918GL-Z, the LTC3857EGN-1#TRPBF offers higher input voltage rating (38V vs. 28V) and EXTVCC capability for improved efficiency, while LTC3857IGN-1#TRPBF provides identical performance with guaranteed industrial-temperature validation - making the E-grade optimal for cost-sensitive commercial designs needing proven reliability.
Availability
LTC3857EGN-1#TRPBF is available at Aetrix Electronics and suitable for automotive infotainment, industrial PLCs, and battery-powered test equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LTC3857EGN-1#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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LTC3857 product line delivers high-efficiency, dual-phase synchronous buck controllers optimized for demanding power conversion applications where low quiescent current, wide input range, and precise voltage regulation are critical - especially in always-on and battery-constrained systems.
FAQ
What is the maximum input voltage rating for the LTC3857EGN-1#TRPBF?
The LTC3857EGN-1#TRPBF has an absolute maximum input supply voltage (VIN) rating of 40V, with a recommended operating range of 4V to 38V. This makes it suitable for 24V industrial systems and 12V automotive applications with load-dump transients. Exceeding 40V risks permanent damage per Absolute Maximum Ratings.
Does the LTC3857EGN-1#TRPBF support phase synchronization with external clocks?
Yes, the LTC3857EGN-1#TRPBF supports phase synchronization via its PLLIN/MODE pin. When an external clock is applied, the internal phase-locked loop aligns the rising edge of TG1 with the external clock's rising edge. The supported sync frequency range is 75kHz to 850kHz, enabling coordinated switching across multiple converters to reduce system-level ripple.
How does the LTC3857EGN-1#TRPBF achieve low quiescent current in sleep mode?
The LTC3857EGN-1#TRPBF achieves 50μA quiescent current in single-channel sleep mode by disconnecting the error amplifier output from the ITH pin, parking ITH at 0.450V, and disabling non-essential internal circuitry. In dual-channel sleep, IQ rises to 65μA. Shutdown (both RUN pins <0.7V) further reduces IQ to <8μA - critical for battery longevity in always-on systems.
Can the LTC3857EGN-1#TRPBF operate with only one output enabled?
Yes, the LTC3857EGN-1#TRPBF supports independent channel control via RUN1 and RUN2 pins. Pulling RUN1 <1.26V disables Channel 1 while Channel 2 remains fully operational, and vice versa. Both channels can be independently configured for different output voltages, light-load modes, and soft-start profiles - enabling flexible multi-rail power architectures.
What is the purpose of the EXTVCC pin on the LTC3857EGN-1#TRPBF?
The EXTVCC pin on the LTC3857EGN-1#TRPBF allows an external 4.7V–14V supply to power the INTVCC LDO, bypassing the internal VIN-based regulator. This improves overall system efficiency when a clean, regulated auxiliary rail (e.g., from a secondary converter) is available - reducing heat dissipation and enabling higher input voltage operation without INTVCC dropout.
LTC3857EGN-1#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- PolyPhase®
- Package/Case:
- 28-SSOP (0.154", 3.90mm Width)
- 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):
- 99.4%
- 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:
- 28-SSOP
LTC3857EGN-1#TRPBF FAQ
1.How can I place an order for LTC3857EGN-1#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3857EGN-1#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 LTC3857EGN-1#TRPBF reliable?
The price and inventory of LTC3857EGN-1#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3857EGN-1#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3857EGN-1#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3857EGN-1#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3857EGN-1#TRPBF?
LTC3857EGN-1#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3857EGN-1#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 LTC3857EGN-1#TRPBF?
For technical support, including LTC3857EGN-1#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3857EGN-1#TRPBF requirements.
6.How does Aetrix verify that LTC3857EGN-1#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3857EGN-1#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 LTC3857EGN-1#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3857EGN-1#TRPBF?
All LTC3857EGN-1#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3857EGN-1#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 LTC3857EGN-1#TRPBF part is unused and in its original packaging.
Return procedure for LTC3857EGN-1#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3857EGN-1#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…
