My Inquiry
My Account
Analog Devices Inc. LTC3872IDDB#TRPBF
- Part No.:
- LTC3872IDDB#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 8-WFDFN Exposed Pad
- Datasheet:
-
LTC3872IDDB#TRPBF.pdf
- Description:
- IC REG CTRLR BOOST 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,151
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3872IDDB#TRPBF from Analog Devices (formerly Linear Technology) is a constant-frequency current-mode boost DC/DC controller driving an external N-channel MOSFET without requiring a sense resistor. It operates from 2.75V to 9.8V input, delivers up to 60V output, achieves ±1.5% voltage accuracy, and supports 550kHz switching for compact 3.3V-to-5V/2A telecom power supplies.
For engineers reviewing the LTC3872IDDB#TRPBF datasheet, LTC3872IDDB#TRPBF pinout, LTC3872IDDB#TRPBF application, or LTC3872IDDB#TRPBF equivalent, key selection criteria include No RSENSE operation, adjustable current limit via IPRG pin, internal soft-start, pulse-skipping at light load, and thermal performance in the 2mm × 3mm DFN package with exposed pad.
Technical Context
The LTC3872IDDB#TRPBF implements a No RSENSE current-sensing architecture that monitors voltage drop across the power MOSFET's RDS(ON), eliminating external sense resistors and improving efficiency. Its current-mode control loop uses the ITH pin as error amplifier output and current comparator threshold reference, enabling fast line/load transient response.
It integrates a 550kHz oscillator with duty-cycle-dependent frequency reduction above ~80% duty cycle to maintain minimum off-time, supports internal/external soft-start via RUN/SS pin, and features undervoltage lockout (UVLO) with 2.3V rising threshold. The device is rated for –40°C to 125°C junction temperature and uses slope compensation internally to prevent subharmonic oscillation above 50% duty cycle.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.75V to 9.8V - supports single-cell Li-ion, 3.3V logic rails, and industrial 5V/9V supplies without level-shifting. |
| Output Voltage Range | Up to 60V - enables high-ratio boost for telecom, IP phone, and 42V automotive auxiliary rails. |
| Switching Frequency | 550kHz typical - allows use of small 1µH inductors and reduces output capacitor RMS ripple requirements. |
| Feedback Accuracy | ±1.5% over temperature - ensures stable regulation under varying thermal and load conditions in embedded systems. |
| Current Limit Threshold | 65–290mV (adjustable via IPRG pin) - sets peak inductor current without external components, supporting flexible MOSFET selection. |
| UVLO Threshold | 2.3V (rising), 2.05V (falling) - prevents erratic startup during brownout and ensures clean shutdown below battery depletion voltage. |
| Thermal Range | –40°C to 125°C junction - qualified for industrial and extended-temperature automotive subsystems. |
| Package Thermal Resistance | θJA = 76°C/W (DFN) - enables higher continuous output current vs TSOT-23 when PCB copper area is optimized. |
Pinout & Package
The LTC3872IDDB#TRPBF is housed in an 8-lead (3mm × 2mm) plastic DFN package with exposed pad (Pin 9), which must be soldered to PCB ground for thermal and electrical integrity. Package thickness is 0.75mm max, compatible with automated SMT assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IPRG (Pin 1) | Current limit select input | Configures peak current threshold (65/130/215mV typ) by tying to GND/VIN/floating - determines MOSFET RDS(ON) compatibility and max output current. |
| ITH (Pin 2) | Error amplifier compensation node | Carries loop compensation signal (0.7–1.9V range); external RC network here sets bandwidth and phase margin. |
| VFB (Pin 3) | Feedback input | Monitors resistor-divider output voltage; internal 1.2V reference enables precise VOUT programming (e.g., 5V = 1.2V × (1 + R2/R1)). |
| GND (Pin 4, Exposed Pad Pin 9) | Power and signal ground | Primary return path for gate drive, feedback, and bias currents; exposed pad must be thermally connected to ≥2 cm² PCB copper. |
| NGATE (Pin 5) | N-MOSFET gate driver output | Drives external high-side N-channel switch with 40ns rise/fall times into 3000pF - requires Schottky clamp for negative voltage protection. |
| VIN (Pin 6) | Supply input | Bias source for internal circuitry and gate driver; must be decoupled with ≥1µF ceramic capacitor placed within 2mm of pin. |
| RUN/SS (Pin 7) | Enable and soft-start control | Pull below 0.85V to shut down (IQ = 8µA); connect capacitor for linear VITH ramp and controlled inrush current. |
| SW (Pin 8) | Switch node interface | Connects to MOSFET drain and inductor; senses current via RDS(ON) or external resistor; rated to 60V max - critical for layout EMI control. |
Key Features
| Feature | Design Value |
|---|---|
| No RSENSE current sensing | Eliminates 5–10mΩ sense resistor, saving >15mm² board area and 0.5–1.2W conduction loss in 2A applications. |
| Adjustable current limit | Three discrete thresholds (GND/VIN/floating IPRG) allow optimization for MOSFET RDS(ON) from 5mΩ to 50mΩ without redesign. |
| Pulse-skipping at light load | Maintains constant 550kHz operation down to ~10mA load while reducing quiescent current to <35µA - improves standby efficiency. |
| Internal soft-start + optional external | 1ms default ramp prevents inrush; adding 100nF to RUN/SS extends start time to ~70ms - protects input supply and output capacitors. |
| High-voltage SW pin rating | 60V absolute max enables direct MOSFET sensing in 48V telecom and 36V industrial boost converters without level-shifting. |
| DFN thermal performance | θJA = 76°C/W (vs 195°C/W for TSOT-23) allows 30% higher continuous output current with identical PCB layout. |
Applications
| Telecom Power Supplies | 42V Automotive Systems |
|---|---|
Use Scenario: Generating isolated 5V/2A bias rail from 3.3V backplane in VoIP gateway with strict EMI limits. IC Role / Device Role / Timing Role: Boost controller managing MOSFET switching, current sensing, and feedback regulation - no external clock required. Use Value: No RSENSE architecture reduces heat generation and eliminates sense resistor tolerance errors, improving long-term output stability over temperature. | Use Scenario: Powering infotainment USB ports from 12V battery during cold-crank (down to 6V input). IC Role / Device Role / Timing Role: High-efficiency boost regulator maintaining 5V/1.5A output despite wide VIN variation and transient load steps. Use Value: UVLO with 2.05V hysteresis prevents dropout-induced resets; 125°C rating ensures reliability in engine bay proximity mounting. |
| 24V Industrial Controls | IP Phone Power Supplies |
Use Scenario: Converting 24V DC bus to 48V PoE midspan injector auxiliary supply with minimal footprint. IC Role / Device Role / Timing Role: Constant-frequency current-mode controller delivering precise 48V output with ±1.5% accuracy across 0–85°C ambient. Use Value: 550kHz operation enables 2.2µH inductor and 22µF ceramic output cap - reduces solution size by 40% vs 300kHz alternatives. | Use Scenario: Onboard 5V/1A power for SIP processor and Ethernet PHY in space-constrained IP desk phone. IC Role / Device Role / Timing Role: Compact boost controller using DFN package and integrated slope compensation to meet EN55022 Class B emissions. Use Value: Pulse-skipping mode maintains >85% efficiency at 10mA standby load - extends PoE power budget for always-on features. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar boost controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3872EDDB#TRPBF | Same pinout and functionality, but rated for 0°C to 85°C junction temperature (vs –40°C to 125°C for LTC3872IDDB#TRPBF). | Suitable for commercial indoor equipment only; not qualified for industrial or automotive thermal environments. | Select LTC3872EDDB#TRPBF only if ambient operating temperature remains below 70°C and cost sensitivity outweighs thermal margin. |
| TPS55340RTER | Integrated 5A MOSFET, fixed 2.5MHz frequency, no IPRG pin - requires external current sense resistor and offers lower quiescent current (12µA). | Better for ultra-compact, low-input-voltage (<5V) designs where integration trumps flexibility; lacks No RSENSE advantage. | Choose TPS55340RTER when board space is critical and MOSFET RDS(ON) > 20mΩ is acceptable; avoid if >50V output or adjustable current limit is needed. |
Compared with LTC3872EDDB#TRPBF, the LTC3872IDDB#TRPBF provides 40°C wider operating range and higher reliability in thermally demanding deployments; versus TPS55340RTER, it trades integration for superior efficiency, higher output voltage capability, and design flexibility via external MOSFET selection.
Availability
LTC3872IDDB#TRPBF is available at Aetrix Electronics and suitable for telecom power supplies, 42V automotive systems, and 24V industrial controls requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LTC3872IDDB#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 precision analog and power management portfolio. Linear pioneered high-performance DC/DC controllers with proprietary architectures like No RSENSE.
The LTC3872IDDB#TRPBF belongs to Linear's current-mode boost controller family designed specifically for high-efficiency, low-component-count DC/DC conversion in space- and thermal-constrained applications such as telecom infrastructure and automotive subsystems.
FAQ
What is the maximum output voltage supported by the LTC3872IDDB#TRPBF?
The LTC3872IDDB#TRPBF supports output voltages up to 60V, as confirmed by the SW pin absolute maximum rating of –0.3V to 60V and validated in typical applications targeting 48V PoE and 36V industrial rails. This enables direct MOSFET sensing without external level-shifting circuitry, preserving efficiency and simplifying design.
Does the LTC3872IDDB#TRPBF require an external current sense resistor?
No, the LTC3872IDDB#TRPBF implements No RSENSE architecture that senses current through the RDS(ON) of the external N-channel MOSFET, eliminating the need for a discrete sense resistor. This reduces component count, board area, and conduction losses - a core feature confirmed in the device description, functional diagram, and application circuits.
What is the purpose of the IPRG pin on the LTC3872IDDB#TRPBF?
On the LTC3872IDDB#TRPBF, the IPRG pin selects the peak current limit threshold: 65mV (IPRG = GND), 130mV (IPRG = floating), or 215mV (IPRG = VIN). This adjusts the maximum inductor current without external components, allowing optimization for different MOSFET RDS(ON) values and load requirements per the Electrical Characteristics table.
Can the LTC3872IDDB#TRPBF operate with a 3.3V input to generate 5V at 2A?
Yes, the LTC3872IDDB#TRPBF is explicitly validated for 3.3V-to-5V/2A boost conversion in its Typical Application schematic (Figure TA01), achieving >90% efficiency at full load. Input voltage range (2.75V–9.8V), 550kHz switching, and No RSENSE operation make it ideal for this exact use case in telecom and IP phone power supplies.
How does the LTC3872IDDB#TRPBF handle thermal management in the DFN package?
The LTC3872IDDB#TRPBF uses an 8-lead 2mm × 3mm DFN with exposed pad (Pin 9), specified with θJA = 76°C/W. Effective thermal management requires soldering the exposed pad to ≥2 cm² of inner-layer or bottom-side PCB copper connected to ground, enabling reliable operation at 125°C junction temperature in industrial environments.
LTC3872IDDB#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Up
- Output Configuration:
- Positive
- Topology:
- Boost
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 2.75V ~ 9.8V
- Frequency - Switching:
- 550kHz
- Duty Cycle (Max):
- -
- Synchronous Rectifier:
- No
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable, Soft Start
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (3x2)
LTC3872IDDB#TRPBF FAQ
1.How can I place an order for LTC3872IDDB#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3872IDDB#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 LTC3872IDDB#TRPBF reliable?
The price and inventory of LTC3872IDDB#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3872IDDB#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3872IDDB#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3872IDDB#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3872IDDB#TRPBF?
LTC3872IDDB#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3872IDDB#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 LTC3872IDDB#TRPBF?
For technical support, including LTC3872IDDB#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3872IDDB#TRPBF requirements.
6.How does Aetrix verify that LTC3872IDDB#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3872IDDB#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 LTC3872IDDB#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3872IDDB#TRPBF?
All LTC3872IDDB#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3872IDDB#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 LTC3872IDDB#TRPBF part is unused and in its original packaging.
Return procedure for LTC3872IDDB#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3872IDDB#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…
