My Inquiry
My Account
Analog Devices Inc. LTC3879IMSE#PBF
- Part No.:
- LTC3879IMSE#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 16-TFSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
LTC3879IMSE#PBF.pdf
- Description:
- IC REG CTRLR BUCK 16MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:387
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3879IMSE#PBF from Analog Devices (formerly Linear Technology) is a synchronous step-down switching regulator controller optimized for high-frequency operation and fast transient response in wide-input industrial power supplies. It features valley current mode control without external sense resistors, ±1% 0.6V reference, 43ns minimum on-time, and dual N-channel MOSFET drive - enabling efficient 1.2V/15A conversion from 4.5V–28V input in communications infrastructure and embedded computing systems.
For engineers reviewing the LTC3879IMSE#PBF datasheet, LTC3879IMSE#PBF pinout, LTC3879IMSE#PBF application, or LTC3879IMSE#PBF equivalent, key selection criteria include its no-RSENSE valley current sensing architecture, programmable current limit with foldback, forced continuous/discontinuous mode control via MODE pin, and compatibility with low-ESR ceramic output capacitors in thermally enhanced MSOP packaging.
Technical Context
The LTC3879IMSE#PBF implements constant-on-time valley current mode control using the bottom MOSFET's RDS(ON) as the current sense element - eliminating external sense resistors and slope compensation. Its ITH pin sets the valley current threshold from 0V to 2.4V, while VRNG pin scales the maximum VDS sense voltage (22mV to 98mV typical) across operating conditions.
Switching frequency is set by an external resistor on the ION pin and compensated for VIN variations to maintain line stability. The RUN pin enables three-state bias control (shutdown, INTVCC-only, full operation), and TRACK/SS supports either soft-start ramping or precise rail tracking of external references during power-up.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4V to 38V - supports wide industrial input rails including 5V, 12V, 24V, and 28V bus systems without derating. |
| Feedback Reference | ±1% 0.6V - enables accurate regulation down to 0.6V output or up to 90% VIN with external resistor divider. |
| Min On-Time | 43ns - allows stable high-step-down ratios (e.g., 28V→1.2V at 400kHz) without pulse-skipping instability. |
| Valley Current Sense | 22mV to 98mV (VRNG-programmable) - uses MOSFET RDS(ON) for lossless sensing; eliminates sense resistor power loss and board space. |
| Switching Frequency | User-programmable via ION resistor - maintains pseudo-fixed frequency across VIN variation for predictable EMI and filter design. |
| Output Protection | Programmable current limit with foldback + output overvoltage protection - prevents damage during short-circuit or feedback fault conditions. |
| Package | 16-pin MSOP with exposed thermal pad - provides 40°C/W θJA for high-current applications in compact layouts. |
Pinout & Package
Package: 16-lead plastic MSOP (MSE) with exposed SGND pad (Pin 17), rated for –40°C to 85°C operation. Exposed pad must be soldered to PCB for thermal and electrical performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| TRACK/SS (1) | Soft-start & tracking input | Internal 1μA pull-up; capacitor-to-ground sets soft-start ramp time; external voltage divider enables precise rail tracking. |
| PGOOD (2) | Open-drain power-good flag | Asserts low when VOUT deviates >±10% from regulation - used for system sequencing and fault reporting. |
| VRNG (3) | VDS sense range select | Sets max valley current sense threshold (22–98mV); tied to SGND → 30mV default, to INTVCC → 75mV default. |
| MODE (4) | Continuous/discontinuous mode control | SGND = forced continuous mode; INTVCC = automatic DCM at light load for higher efficiency. |
| ITH (5) | Error amplifier output & current threshold | 0–2.4V control voltage sets valley current limit; also serves as compensation node for loop stability. |
| SGND (6) | Signal ground reference | Reference for all small-signal pins; must connect to PGND at single point to avoid noise coupling. |
| ION (7) | On-time timer current input | Resistor from VIN sets switching frequency; internal 0.7V clamp enables VIN-compensated timing. |
| VFB (8) | Feedback input | Compares output divider voltage to 0.6V reference; high-impedance input (<±50nA) minimizes divider error. |
| RUN (9) | Enable/shutdown control | Three-state operation: <0.7V = micropower shutdown (18μA); 0.7–1.5V = INTVCC enabled, no switching; >1.5V = full operation. |
| VIN (10) | Main power input | 4–38V supply; requires RC filter to PGND for noise immunity in noisy industrial environments. |
| INTVCC (11) | Internal 5.3V regulator output | Powers gate drivers and control logic; requires ≥1μF X5R/X7R ceramic decoupling to PGND. |
| BG (12) | Bottom gate driver | Drives synchronous N-MOSFET source-to-PGND; 0.7Ω pull-down / 2.5Ω pull-up ensures fast turn-off/turn-on. |
| PGND (13) | Power ground return | Low-inductance connection point for bottom MOSFET source, CIN, and CINTVCC - critical for current sensing accuracy. |
| SW (14) | Switch node | Connects to bootstrap capacitor negative terminal; swings from ~–0.3V to VIN - requires low-inductance layout. |
| TG (15) | Top gate driver | Drives top N-MOSFET source-to-SW; 1.2Ω pull-down / 2.5Ω pull-up enables fast switching with minimal shoot-through risk. |
| BOOST (16) | Bootstrap supply | Connects to bootstrap capacitor positive terminal; floats between (INTVCC–Vf) and (VIN+INTVCC–Vf) for high-side drive. |
Key Features
| Feature | Design Value |
|---|---|
| No RSENSE valley current sensing | Eliminates 0.5–2W sense resistor losses and associated board area; leverages MOSFET RDS(ON) for accurate, temperature-compensated current measurement. |
| Adjustable output soft-start or tracking | Enables controlled power-up sequencing in multi-rail systems - prevents inrush current and ensures safe voltage ramp alignment across ICs. |
| Programmable current limit with foldback | Reduces MOSFET stress during sustained overload or short-circuit by lowering current limit as VOUT collapses - improves reliability without external circuitry. |
| Stable with low-ESR ceramic output capacitors | Supports modern high-capacitance, low-impedance MLCC arrays (e.g., 330μF total) - reduces output ripple and improves transient response vs. electrolytic solutions. |
| Smooth start-up into pre-biased output | Allows hot-swap or rail-sharing configurations where output voltage is already present - prevents reverse current flow and system disruption. |
Applications
| Telecom Power Supply | Industrial PLC CPU Board |
|---|---|
Use Scenario: 28V backplane powering 1.2V/15A FPGA core rail in 48V telecom shelf with strict EMI limits. IC Role / Device Role / Timing Role: Primary step-down controller managing high-current, high-efficiency conversion with forced continuous mode to suppress subharmonic noise. Use Value: 43ns min on-time enables stable 28V→1.2V conversion at 400kHz; no-RSENSE architecture avoids 1.2W heat generation in confined chassis space. | Use Scenario: 24V factory automation input converted to isolated 3.3V/5A and 1.8V/3A rails for ARM-based controller and I/O peripherals. IC Role / Device Role / Timing Role: Main buck controller for highest-current rail; TRACK/SS pin synchronized to secondary controller for coordinated power sequencing. Use Value: Programmable soft-start prevents inrush-induced brownouts on shared 24V bus; PGOOD output triggers watchdog reset if main rail fails. |
| High-Density Server VRM | Medical Imaging Data Acquisition |
Use Scenario: 12V intermediate bus delivering 0.85V/60A to GPU ASIC in space-constrained server blade with thermal budget <5°C rise. IC Role / Device Role / Timing Role: High-frequency valley current mode controller driving paralleled MOSFETs; MODE pin set to INTVCC for DCM at idle to reduce standby power. Use Value: 16-pin MSOP package with exposed pad achieves 40°C/W θJA; valley current sensing ensures cycle-by-cycle protection across 0–100% load transients. | Use Scenario: Battery-backed 5V input powering precision 1.2V analog front-end for CT scanner ADCs requiring ultra-low noise and zero output droop during battery switchover. IC Role / Device Role / Timing Role: Step-down controller with pre-biased start-up capability and tight ±1% reference for stable analog supply. Use Value: Supports smooth transition from AC adapter to battery without output glitch; ±0.6mV reference drift over –40°C to 85°C ensures consistent ADC LSB calibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-down controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3880IUH#PBF | Digital PMBus interface, integrated 12-bit ADC, dual-output capability; requires external EEPROM for configuration. | Used where remote monitoring, margining, or dynamic voltage scaling is required - not suitable for cost-sensitive analog-only designs. | Select LTC3880IUH#PBF only when digital telemetry and closed-loop calibration justify added BOM cost and firmware overhead. |
| MP2918GL-Z | Analog controller with similar 4–38V input, but fixed 0.6V reference tolerance (±1.5%), no VRNG programmability, and 65ns min on-time. | Acceptable for less demanding 12V→3.3V/5A applications where 43ns timing headroom is unnecessary. | Choose MP2918GL-Z for price-sensitive industrial SMPS where valley current sensing and sub-50ns on-time are not critical. |
Compared with LTC3879IMSE#PBF, LTC3880IUH#PBF adds digital configurability at the cost of complexity and cost, while MP2918GL-Z offers lower price but sacrifices timing precision and sense threshold flexibility - making LTC3879IMSE#PBF optimal for high-performance analog-controlled high-step-down converters.
Availability
LTC3879IMSE#PBF is available at Aetrix Electronics and suitable for distributed power systems, embedded computing platforms, and communications infrastructure requiring stable component supply with guaranteed long-term manufacturability.
Supply support for LTC3879IMSE#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 power management semiconductors, formed through the acquisition of Linear Technology in 2017.
The LTC3879 belongs to ADI's high-efficiency DC/DC controller product line, designed specifically for high-frequency, wide-input industrial and telecom power supplies where fast transient response and no-RSENSE operation are critical.
FAQ
What is the minimum on-time specification for the LTC3879IMSE#PBF and why does it matter?
The LTC3879IMSE#PBF has a guaranteed minimum on-time of 43ns. This parameter directly determines the lowest achievable output voltage at a given input voltage and switching frequency - for example, enabling stable 28V→1.2V conversion at 400kHz. Shorter minimum on-time prevents pulse-skipping and maintains regulation under high step-down ratios, which is essential for modern low-voltage, high-current ASIC and FPGA supplies.
How does the VRNG pin affect current sensing accuracy in the LTC3879IMSE#PBF?
The VRNG pin on the LTC3879IMSE#PBF sets the maximum allowable valley current sense threshold between 22mV and 98mV. When VRNG is tied to SGND, the device defaults to ~30mV; when tied to INTVCC, it operates at ~75mV. This scaling allows optimization for different MOSFET RDS(ON) values and temperature ranges - ensuring accurate current limiting across process and thermal variation without external components.
Can the LTC3879IMSE#PBF start up into a pre-biased output, and how is this enabled?
Yes, the LTC3879IMSE#PBF supports smooth start-up into a pre-biased output. This is enabled by default - no configuration required. During start-up, the controller monitors the VFB pin and prevents reverse current flow by keeping both MOSFETs off until the TRACK/SS voltage exceeds the internal 0.6V reference. This feature is critical for hot-swap applications and redundant power systems where output voltage may already be present.
What is the role of the MODE pin on the LTC3879IMSE#PBF, and how does it impact efficiency?
The MODE pin on the LTC3879IMSE#PBF selects between forced continuous conduction mode (CCM) and automatic discontinuous conduction mode (DCM). When MODE is grounded, CCM is enforced at all loads - minimizing output ripple but reducing light-load efficiency. When MODE is tied to INTVCC, the controller automatically enters DCM below ~50% load, cutting switching losses and improving efficiency by up to 8% at 100mA load in typical 12V→1.2V designs.
Does the LTC3879IMSE#PBF require external slope compensation, and why or why not?
No, the LTC3879IMSE#PBF does not require external slope compensation. Its valley current mode architecture with constant on-time control inherently stabilizes the current loop across all duty cycles - eliminating the subharmonic oscillation risk that necessitates slope compensation in peak current mode controllers. This simplifies design, reduces component count, and improves reliability in high-step-down applications.
LTC3879IMSE#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-TFSOP (0.118", 3.00mm Width) Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 4V ~ 38V
- Frequency - Switching:
- -
- Duty Cycle (Max):
- -
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Enable, Power Good, Soft Start, Tracking
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-MSOP-EP
LTC3879IMSE#PBF FAQ
1.How can I place an order for LTC3879IMSE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3879IMSE#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 LTC3879IMSE#PBF reliable?
The price and inventory of LTC3879IMSE#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3879IMSE#PBF is usually 5 days.
3.What payment methods are accepted for LTC3879IMSE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3879IMSE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3879IMSE#PBF?
LTC3879IMSE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3879IMSE#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 LTC3879IMSE#PBF?
For technical support, including LTC3879IMSE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3879IMSE#PBF requirements.
6.How does Aetrix verify that LTC3879IMSE#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3879IMSE#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 LTC3879IMSE#PBF meets industry standards.
7.What is the process for return or replacement of LTC3879IMSE#PBF?
All LTC3879IMSE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3879IMSE#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 LTC3879IMSE#PBF part is unused and in its original packaging.
Return procedure for LTC3879IMSE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3879IMSE#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…
