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Analog Devices Inc. LT3972EMSE#TRPBF
- Part No.:
- LT3972EMSE#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
LT3972EMSE#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 3.5A 10MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,405
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Product details
Overview
LT3972EMSE#TRPBF from Analog Devices (formerly Linear Technology) is a monolithic current-mode step-down switching regulator IC designed for wide-input automotive and industrial power conversion. It operates from 3.6V to 33V input, delivers up to 3.5A output current, features 75µA quiescent current in Burst Mode®, supports adjustable 200kHz–2.4MHz switching frequency, and integrates a 95mΩ NPN switch with on-chip boost Schottky diode driver. It is used in distributed 12V/24V supply regulation where low-noise, high-efficiency light-load performance is critical.
For engineers reviewing the LT3972EMSE#TRPBF datasheet, LT3972EMSE#TRPBF pinout, LT3972EMSE#TRPBF application, or LT3972EMSE#TRPBF equivalent, key selection considerations include its 33V max operating input (62V transient tolerant), integrated bias-from-VOUT capability above 3V, power good flag with 91% threshold, soft-start via RUN/SS pin, and thermal shutdown - all in a 10-pin MSOP package with exposed pad.
Technical Context
The LT3972EMSE#TRPBF implements constant-frequency current-mode control with internal slope compensation, enabling fast transient response and stable loop behavior across wide duty cycles. Its oscillator is resistor-programmable (RT pin) and supports external synchronization (SYNC pin) from 250kHz to 2MHz.
It uses bipolar NPN switch topology driven by an internal boost circuit (BD/BOOST pins), requiring external Schottky diode and capacitor. Bias current can be drawn from VOUT when >3V, reducing VIN quiescent draw. Power good (PG) asserts open-collector low until FB reaches 91% of regulation, and overvoltage lockout disables switching above 33V (min) while sustaining 62V transients.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.6V to 33V continuous; withstands 62V non-repetitive transients - enables direct connection to automotive battery or industrial 24V/36V rails. |
| Max Output Current | 3.5A - sufficient for powering FPGAs, microcontrollers, and sensor subsystems without external current boosting. |
| Quiescent Current | 75µA at 12VIN → 3.3VOUT in Burst Mode® - extends battery life in always-on systems like telematics or remote sensors. |
| Switching Frequency | 200kHz to 2.4MHz (adjustable via RT resistor) - allows trade-off between small magnetics (high-f) and efficiency/EMI (low-f). |
| Feedback Reference | 0.790V ±10mV - enables precise output regulation from 0.79V to 30V using standard resistor dividers. |
| Thermal Range | –40°C to +125°C junction - qualified for under-hood automotive and industrial control cabinet environments. |
| Shutdown Current | <1µA - ensures negligible battery drain during system sleep or standby modes. |
Pinout & Package
LT3972EMSE#TRPBF is housed in a thermally enhanced 10-lead plastic MSOP package (MSE) with exposed pad (Pin 11) soldered to PCB ground for low θJA = 45°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BD (1) | Boost Diode Anode Input | Connects to Schottky diode anode; supplies bias current to internal regulator - enables efficient VOUT-derived bias when VOUT > 3V. |
| BOOST (2) | Bootstrap Drive Voltage | Provides >VIN voltage to fully saturate internal NPN switch - requires external boost capacitor and Schottky diode. |
| SW (3) | Switch Node | Output of internal NPN power switch - connects to inductor, catch diode cathode, and boost capacitor. |
| VIN (4) | Main Power Input | Supplies internal regulator and switch driver - must be locally bypassed with ≥10µF ceramic capacitor. |
| RUN/SS (5) | Enable & Soft-Start Control | Logic-level enable (≥2.5V = on); RC ramp on this pin controls output voltage slew rate during startup. |
| SYNC (6) | External Clock Input | Accepts TTL/CMOS clock (250kHz–2MHz) to synchronize switching - reduces EMI in multi-regulator systems. |
| PG (7) | Power Good Flag | Open-collector output active-low when VOUT reaches 91% of target - used for system sequencing and fault monitoring. |
| FB (8) | Feedback Input | Regulated to 0.790V; connects to resistor divider tap - sets output voltage with ±1% accuracy over temperature. |
| VC (9) | Error Amplifier Output | Controls peak switch current; RC compensation network here stabilizes control loop dynamics. |
| RT (10) | Oscillator Frequency Set | Resistor-to-ground sets switching frequency (200kHz–2.4MHz) - enables optimization for size vs. efficiency. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Boost Diode Driver | Eliminates need for external gate driver; enables use of low-VF Schottky diodes for high efficiency at light loads. |
| Burst Mode® Operation | Maintains <15mVP-P output ripple while achieving 75µA IQ - ideal for battery-powered IoT nodes and always-on ECUs. |
| Overvoltage Lockout (OVL) | Disables switching at VIN >33V (min), protecting downstream circuitry during load dump or alternator surges. |
| Thermal Shutdown Protection | Halts operation if junction exceeds safe limit - prevents damage during overload or poor heatsinking conditions. |
| Saturating NPN Switch | 95mΩ RDS(on)-equivalent on-resistance - delivers high efficiency even at full 3.5A load with minimal thermal rise. |
Applications
| Automotive Battery Regulation | Distributed Supply Regulation |
|---|---|
Use Scenario: Regulating 12V/24V vehicle battery (with 62V load-dump transients) to 3.3V/5V for infotainment MCU and CAN transceivers. IC Role / Device Role / Timing Role: Primary buck converter providing isolated, ripple-controlled DC power with OVL and PG signaling. Use Value: Survives ISO 7637-2 pulse 5a (62V/100ms) without latch-off; PG flag enables safe boot sequencing of domain controllers. | Use Scenario: Local point-of-load conversion in industrial PLC backplanes where 24V rail powers multiple 5V/3.3V submodules. IC Role / Device Role / Timing Role: High-current, thermally robust buck regulator with programmable fSW to minimize EMI coupling between adjacent slots. Use Value: Adjustable frequency avoids sensitive bands (e.g., 400kHz for EMC compliance); exposed-pad MSOP simplifies thermal design in dense layouts. |
| Industrial Supplies | Wall Transformer Regulation |
Use Scenario: Replacing linear regulators in factory automation sensors requiring 3.3V @ 2A from unregulated 9–30V DC inputs. IC Role / Device Role / Timing Role: Efficient, wide-input buck converter with low IQ to extend operational uptime in energy-harvested or capacitor-backed systems. Use Value: 75µA Burst Mode® IQ enables >1-year battery life in wireless vibration monitors; thermal shutdown prevents field failures. | Use Scenario: Stepping down rectified AC wall adapter output (e.g., 36V DC) to 5V for USB-powered embedded devices. IC Role / Device Role / Timing Role: High-vin buck regulator with integrated boost drive, eliminating need for external MOSFET drivers in compact adapters. Use Value: 33V operating limit and 62V transient tolerance allow direct use with low-cost, unfiltered 36V SMPS outputs - reducing BOM count. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3631EMSE#TRPBF | Lower max IOUT (1.5A), fixed 2MHz fSW, no SYNC, higher IQ (120µA) | Targeted for ultra-compact, low-power applications; lacks OVL and PG flag | Choose when board space is constrained and 3.5A output is unnecessary; verify thermal margin at full load. |
| MP2451DT-LF-Z | 36V max VIN, 0.6A IOUT, no integrated boost driver, no PG, lower cost | Cost-sensitive consumer-grade designs; not AEC-Q200 qualified | Use only in non-automotive, non-safety-critical applications where 3.5A output and 62V surge immunity are not required. |
Compared with LTC3631EMSE#TRPBF and MP2451DT-LF-Z, the LT3972EMSE#TRPBF uniquely combines 3.5A output, 62V transient tolerance, integrated boost drive, and power good signaling - making it the only option among the three suitable for automotive front-end power stages and industrial 24V/36V PoL conversion.
Availability
LT3972EMSE#TRPBF is available at Aetrix Electronics and suitable for automotive battery regulation, distributed supply regulation, and industrial power supplies requiring stable component supply, long-term lifecycle support, and guaranteed AEC-Q200-aligned reliability.
Supply support for LT3972EMSE#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.
The LT3972 product line was designed specifically for rugged, wide-input DC/DC conversion in automotive, industrial, and avionics applications - emphasizing transient robustness, low-light-load IQ, and integrated functionality to reduce external component count.
FAQ
What is the maximum input voltage rating for LT3972EMSE#TRPBF in continuous operation?
The LT3972EMSE#TRPBF has a maximum continuous input voltage rating of 33V. It can withstand non-repetitive transients up to 62V for one minute, but sustained operation above 33V will trigger overvoltage lockout and disable switching. This makes LT3972EMSE#TRPBF suitable for automotive battery systems subject to ISO 7637-2 load-dump pulses.
Does LT3972EMSE#TRPBF require an external Schottky diode, and why?
Yes, LT3972EMSE#TRPBF requires an external Schottky diode connected between BD and SW pins. The IC integrates a boost diode driver but not the diode itself - the external diode provides the bootstrap path for the BOOST pin, enabling full saturation of the internal NPN switch. This architecture improves efficiency and allows selection of optimized diodes for specific VF/IR trade-offs.
How does the LT3972EMSE#TRPBF achieve 75µA quiescent current?
The LT3972EMSE#TRPBF achieves 75µA quiescent current through low-ripple Burst Mode® operation: during light loads, it discontinues switching bursts, shuts down internal bias circuitry, and maintains regulation via output capacitor hold-up. Additionally, when VOUT > 3V, it draws bias current from the output rather than VIN - further reducing input supply current. This behavior is confirmed in the datasheet's Typical Performance Characteristics (Figure G01–G03).
Can LT3972EMSE#TRPBF be synchronized to an external clock, and what is the supported range?
Yes, LT3972EMSE#TRPBF supports external clock synchronization via the SYNC pin. It accepts TTL/CMOS-compatible clock signals from 250kHz to 2MHz. Synchronization helps reduce beat frequencies and EMI in multi-regulator systems. When unused, SYNC must be tied to GND to ensure low-ripple Burst Mode® operation at light loads.
What thermal protection features does LT3972EMSE#TRPBF include?
LT3972EMSE#TRPBF includes thermal shutdown protection that disables switching when the junction temperature exceeds safe limits. Recovery is automatic upon cooling. The device is rated for –40°C to +125°C operating junction temperature, and its 10-lead MSOP package features an exposed pad (Pin 11) that must be soldered to PCB ground to achieve θJA = 45°C/W - critical for maintaining safe operation at full 3.5A load in enclosed environments.
LT3972EMSE#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- 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):
- 33V
- Voltage - Output (Min/Fixed):
- 0.79V
- Voltage - Output (Max):
- 30V
- Current - Output:
- 3.5A
- Frequency - Switching:
- 230kHz ~ 2.45MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-MSOP-EP
LT3972EMSE#TRPBF FAQ
1.How can I place an order for LT3972EMSE#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3972EMSE#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 LT3972EMSE#TRPBF reliable?
The price and inventory of LT3972EMSE#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3972EMSE#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3972EMSE#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3972EMSE#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3972EMSE#TRPBF?
LT3972EMSE#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3972EMSE#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 LT3972EMSE#TRPBF?
For technical support, including LT3972EMSE#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3972EMSE#TRPBF requirements.
6.How does Aetrix verify that LT3972EMSE#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3972EMSE#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 LT3972EMSE#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3972EMSE#TRPBF?
All LT3972EMSE#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3972EMSE#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 LT3972EMSE#TRPBF part is unused and in its original packaging.
Return procedure for LT3972EMSE#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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