My Inquiry
My Account
Analog Devices Inc. LT3481HMSE#PBF
- Part No.:
- LT3481HMSE#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
LT3481HMSE#PBF.pdf
- Description:
- IC REG BUCK ADJ 2A 10MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:235
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3481HMSE#PBF from Analog Devices (formerly Linear Technology) is a high-voltage, current-mode synchronous step-down DC/DC regulator with integrated 0.18Ω NPN switch and boost Schottky diode. It operates from 3.6V to 34V input, delivers up to 2A output, supports adjustable switching frequency from 300kHz to 2.8MHz, and achieves 50μA quiescent current in Burst Mode for battery-powered industrial sensors.
For engineers reviewing the LT3481HMSE#PBF datasheet, LT3481HMSE#PBF pinout, LT3481HMSE#PBF application, or LT3481HMSE#PBF equivalent, key selection criteria include its 150°C junction-rated MSOP package, power-good flag timing behavior, low-ripple Burst Mode operation below 15mV, and bias-current sourcing capability from VOUT ≥3V - all critical for automotive front-end power and ruggedized portable instrumentation.
Technical Context
The LT3481HMSE#PBF implements constant-frequency current-mode control using an internal error amplifier (gm = 330 μMho) that servo-controls peak switch current via the VC pin. Its oscillator is resistor-programmable (RT pin), enabling precise frequency setting between 300kHz and 2.8MHz while supporting synchronization in the 275–475kHz range.
It integrates a bipolar NPN power switch with 0.18Ω on-resistance, uses external BOOST capacitor/diode to drive the switch into saturation, and features active soft-start via RUN/SS pin ramping. The device enters low-IQ shutdown (<1μA) when RUN/SS is pulled below 0.2V and asserts open-collector PG when FB reaches 90% of 1.265V reference.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.6V to 34V operating; 36V absolute max - supports wide-range industrial and automotive battery inputs without external pre-regulation. |
| Max Output Current | 2A continuous - sufficient for powering FPGA I/O banks, microcontroller cores, or dual-rail analog subsystems from single high-voltage rail. |
| Quiescent Current | 50μA at 12VIN/3.3VOUT in Burst Mode - enables multi-year battery life in always-on remote monitoring nodes. |
| Switching Frequency | Adjustable 300kHz–2.8MHz via RT resistor - allows trade-off between inductor size (e.g., 4.7μH at 800kHz) and efficiency in space-constrained designs. |
| Feedback Reference | 1.265V ±15mV over temperature - sets output voltage accuracy for 3.3V, 5V, or custom rails using standard 1% resistors. |
| Power Good Threshold | 90% of programmed VOUT with 5mV hysteresis - provides reliable system reset sequencing without external comparators. |
| Junction Temp Range | –40°C to +150°C - qualified for under-hood automotive, industrial motor drives, and high-ambient embedded control. |
Pinout & Package
LT3481HMSE#PBF is housed in a thermally enhanced 10-lead plastic MSOP package with exposed pad (pin 11), offering θJA = 40°C/W. The exposed pad must be soldered to PCB ground for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BD (Pin 1) | Boost diode anode connection | Connects external Schottky anode to enable BOOST capacitor charging; reverse leakage <2μA ensures stable high-side drive. |
| BOOST (Pin 2) | Boost capacitor voltage node | Provides >VIN voltage to saturate internal NPN switch; rated to 56V with 30V max above SW pin. |
| SW (Pin 3) | Switch node | Drives external inductor and catch diode; 0.18Ω RDS(on) limits conduction loss at 2A load. |
| VIN (Pin 4) | Main input supply | Supplies internal regulator and switch; requires local 4.7μF ceramic bypass; absolute max 36V. |
| RUN/SS (Pin 5) | Enable & soft-start control | Pull ≥2.5V for operation; ramp via RC network controls VOUT rise time; <0.2V enables <1μA shutdown. |
| PG (Pin 6) | Power good open-collector output | Sinks ≥100μA when VFB <90% of 1.265V; requires external pull-up for system reset signaling. |
| BIAS (Pin 7) | Bias supply input | Draws current from VOUT ≥3V to reduce IQ; improves light-load efficiency vs. VIN-only biasing. |
| FB (Pin 8) | Feedback input | Regulated to 1.265V; connects to resistor divider; 30nA bias current minimizes divider error. |
| VC (Pin 9) | Error amplifier output | Controls peak switch current; RC compensation from VC to GND stabilizes loop dynamics. |
| RT (Pin 10) | Oscillator frequency set | Resistor to GND programs fSW; e.g., 8.66kΩ yields 2.8MHz; supports sync in 275–475kHz band. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Boost Diode | Eliminates need for external boost diode; reduces BOM count and layout area in compact 3.3V/5V point-of-load designs. |
| Low-Ripple Burst Mode | Maintains output ripple <15mV at light loads while sustaining 50μA IQ, avoiding audible ceramic capacitor noise in sensitive instrumentation. |
| Power Good Flag | Open-collector PG asserts when VOUT reaches 90% of target; enables deterministic power sequencing in multi-rail systems without extra ICs. |
| Thermally Enhanced MSOP | 10-lead MSOP with exposed pad (θJA = 40°C/W) supports 2A continuous operation at +125°C ambient without heatsink. |
| Output Bias Sourcing | Draws bias current from VOUT ≥3V instead of VIN, improving full-load efficiency by ~2% in high-input-ratio applications (e.g., 24V→3.3V). |
Applications
| Automotive Front-End Power | Industrial Sensor Node Supply |
|---|---|
|
Use Scenario: Regulating 12V/24V vehicle battery to 3.3V for CAN transceiver, MCU, and analog front-end in engine control unit. IC Role / Device Role / Timing Role: Primary buck converter providing isolated, ripple-controlled 3.3V rail with PG signaling for safe MCU boot sequence. Use Value: 150°C rating ensures reliability under hood; 50μA Burst Mode extends battery runtime during sleep; PG eliminates need for external supervisor IC. |
Use Scenario: Powering wireless sensor node (MCU + RF + ADC) from 9V alkaline or LiSOCl₂ primary cell. IC Role / Device Role / Timing Role: High-efficiency step-down regulator maintaining stable 3.3V output across 9V→3.6V battery discharge curve. Use Value: 50μA IQ enables >10-year shelf life; BIAS pin sourcing from VOUT improves efficiency at low loads; soft-start prevents inrush-induced brownout. |
| Distributed Telecom Supply | Ruggedized Portable Instrumentation |
|
Use Scenario: Generating 5V intermediate rail from 48V telecom backplane for downstream POL converters and interface ICs. IC Role / Device Role / Timing Role: Wide-input buck stage delivering 2A with programmable frequency to avoid noise coupling into sensitive SerDes lanes. Use Value: 300kHz–2.8MHz adjustment enables EMI spread-spectrum tuning; 34V max input accommodates 48V transients without clamping. |
Use Scenario: Supplying 3.3V/5V rails in handheld test equipment exposed to –25°C to +70°C ambient and mechanical shock. IC Role / Device Role / Timing Role: Main power IC with robust thermal design, PG flag for self-test initiation, and low-noise regulation for precision ADC references. Use Value: Exposed-pad MSOP ensures stable operation at 150°C junction; low-ripple Burst Mode avoids interference with 24-bit sigma-delta ADC sampling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3631EMSE#PBF | 40V input, 1.5A, 3mm × 3mm DFN, no integrated boost diode, 2.5μA IQ | Lower current, smaller footprint, but requires external boost diode and higher external component count. | Prefer for space-constrained, ultra-low-IQ applications where 1.5A suffices and board area is premium. |
| TPS54202DDCR | 28V input, 2A, 6-pin SOT-23, integrated FETs, 2μA shutdown, no PG or BIAS pin | Smaller package, lower cost, but lacks PG flag, BIAS sourcing, and 150°C rating; not automotive-qualified. | Prefer for cost-sensitive consumer applications with <85°C ambient and no sequencing requirements. |
Compared with LTC3631EMSE#PBF and TPS54202DDCR, LT3481HMSE#PBF uniquely combines 34V input, 2A output, 150°C rating, integrated boost diode, and PG flag - making it the only option qualified for high-temp automotive front-end and industrial distributed power where reliability and feature completeness outweigh minimal size/cost trade-offs.
Availability
LT3481HMSE#PBF is available at Aetrix Electronics and suitable for automotive front-end power, industrial sensor node supply, and distributed telecom supply requiring stable component supply across extended temperature and long product lifecycles.
Supply support for LT3481HMSE#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 (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 LT3481 belongs to Linear's high-voltage monolithic buck regulator family, designed specifically for ruggedized power conversion in automotive, industrial, and aerospace applications where wide input range, high temperature operation, and integrated functionality are mandatory.
FAQ
What is the maximum junction temperature specification for LT3481HMSE#PBF?
The LT3481HMSE#PBF is rated for operation up to +150°C junction temperature, with guaranteed specifications over the –40°C to +150°C case temperature range. This H-grade qualification makes LT3481HMSE#PBF suitable for under-hood automotive and high-ambient industrial environments where standard E- or I-grade parts would derate or fail.
Does LT3481HMSE#PBF require an external boost diode?
No, LT3481HMSE#PBF integrates the boost Schottky diode anode connection (BD pin) and drive circuitry, eliminating the need for an external boost diode. The BD pin connects directly to the cathode of an external Schottky diode whose anode goes to GND - the diode itself remains external, but the boost path control and switching are fully integrated within LT3481HMSE#PBF.
How does the BIAS pin improve efficiency in LT3481HMSE#PBF?
The BIAS pin on LT3481HMSE#PBF allows the IC to draw bias current from the regulated output (when VOUT ≥3V) instead of VIN. This reduces total input current, especially at light loads and high input-to-output voltage ratios - improving full-load efficiency by up to 2% in 24V→3.3V applications and extending battery life in portable systems powered by LT3481HMSE#PBF.
What is the function of the PG (Power Good) pin on LT3481HMSE#PBF?
The PG pin on LT3481HMSE#PBF is an open-collector output that goes high (via external pull-up) when the FB pin voltage reaches 90% of the 1.265V reference - indicating VOUT is within regulation tolerance. It remains valid only when VIN >3.5V and RUN/SS is high, enabling reliable power sequencing and system reset in multi-rail designs without adding discrete supervisors.
Can LT3481HMSE#PBF synchronize to an external clock?
Yes, LT3481HMSE#PBF supports external synchronization in the 275kHz to 475kHz range via the RT pin. When an external clock signal is applied to RT, the internal oscillator locks to it - allowing noise-sensitive systems to avoid switching frequency conflicts with data converters, RF sections, or communication interfaces, which is essential in mixed-signal designs using LT3481HMSE#PBF.
LT3481HMSE#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width) Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.6V
- Voltage - Input (Max):
- 34V
- Voltage - Output (Min/Fixed):
- 1.265V
- Voltage - Output (Max):
- 20V
- Current - Output:
- 2A
- Frequency - Switching:
- 300kHz ~ 2.8MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-MSOP-EP
LT3481HMSE#PBF FAQ
1.How can I place an order for LT3481HMSE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3481HMSE#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 LT3481HMSE#PBF reliable?
The price and inventory of LT3481HMSE#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3481HMSE#PBF is usually 5 days.
3.What payment methods are accepted for LT3481HMSE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3481HMSE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3481HMSE#PBF?
LT3481HMSE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3481HMSE#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 LT3481HMSE#PBF?
For technical support, including LT3481HMSE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3481HMSE#PBF requirements.
6.How does Aetrix verify that LT3481HMSE#PBF is sourced from the original manufacturer or authorized distributors?
All LT3481HMSE#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 LT3481HMSE#PBF meets industry standards.
7.What is the process for return or replacement of LT3481HMSE#PBF?
All LT3481HMSE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3481HMSE#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 LT3481HMSE#PBF part is unused and in its original packaging.
Return procedure for LT3481HMSE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3481HMSE#PBF Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
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…
