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Analog Devices Inc. LT3972IMSE#TRPBF
- Part No.:
- LT3972IMSE#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
LT3972IMSE#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 3.5A 10MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,570
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Product details
Overview
LT3972IMSE#TRPBF from Analog Devices (formerly Linear Technology) is a monolithic current-mode buck switching regulator IC designed for wide-input, high-efficiency DC/DC conversion. It operates from 3.6V to 33V input, delivers up to 3.5A output current, supports adjustable switching frequency from 200kHz to 2.4MHz, and achieves 75μA quiescent current in Burst Mode operation - ideal for automotive battery regulation and industrial power supplies requiring low-noise, thermally robust step-down conversion.
For engineers reviewing the LT3972IMSE#TRPBF datasheet, LT3972IMSE#TRPBF pinout, LT3972IMSE#TRPBF application, or LT3972IMSE#TRPBF equivalent, key selection considerations include its 95mΩ integrated NPN switch, internal boost Schottky diode, power good flag, soft-start via RUN/SS pin, and thermal protection - all in a 10-pin MSOP package with exposed pad for enhanced thermal performance.
Technical Context
The LT3972IMSE#TRPBF implements constant-frequency current-mode control with an internal oscillator set by an external RT resistor. Its bipolar NPN switch is driven via an integrated boost circuit (BD/BOOST pins), enabling full saturation across wide VIN ranges. The error amplifier (VC pin) directly controls peak switch current, while feedback regulation targets 0.790V at the FB pin.
Burst Mode operation reduces quiescent current to 75μA at light loads while maintaining output ripple below 15mVP-P; frequency foldback protects during startup/overload; overvoltage lockout disables switching above 33V (62V transient tolerant); and the PG pin asserts when VOUT reaches 91% of regulation, with valid status conditioned on VIN > 3.6V and RUN/SS high.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.6V to 33V continuous; withstands 62V transients - enables direct connection to 24V/32V automotive or industrial rails without pre-regulation. |
| Max Output Current | 3.5A - sufficient for powering FPGAs, microcontrollers, and sensor subsystems from single-stage conversion. |
| Quiescent Current | 75μA in Burst Mode (12VIN → 3.3VOUT) - extends battery life in always-on systems like telematics or remote sensors. |
| Switch On-Resistance | 95mΩ - minimizes conduction loss and thermal rise at full load, supporting high efficiency (>90% at 12VIN→5VOUT). |
| Feedback Reference | 0.790V ±10mV - allows precise output programming from 0.79V to 30V using standard resistor dividers. |
| Switching Frequency | 200kHz–2.4MHz (RT-programmable) - permits optimization between small magnetics (high-f) and high efficiency/low EMI (low-f). |
| Thermal Range | –40°C to +125°C junction - qualified for under-hood automotive and industrial environments. |
| Power Good Threshold | 91% of regulated VOUT with 65mV hysteresis - provides reliable system sequencing and fault detection without external comparators. |
Pinout & Package
LT3972IMSE#TRPBF is housed in a thermally enhanced 10-lead MSOP package (MSE) with exposed pad (Pin 11) soldered to PCB ground for low θJC = 10°C/W. The package measures 3mm × 3mm × 1.1mm and supports reflow-compatible lead-free assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BD (1) | Boost Diode Anode Input | Connects to Schottky diode anode; supplies bias current to internal regulator - enables efficiency boost when VOUT > 3V. |
| BOOST (2) | Bootstrap Drive Voltage | Provides >VIN voltage to fully saturate internal NPN switch - critical for low VCESAT and high efficiency at high duty cycles. |
| SW (3) | Switch Node | Output of internal power switch - connects to inductor, catch diode cathode, and boost capacitor - defines high-frequency switching node requiring careful layout. |
| VIN (4) | Main Power Input | Supplies internal regulator and switch driver - must be locally bypassed with ≥10μF ceramic capacitor near pin. |
| RUN/SS (5) | Enable & Soft-Start Control | Logic-level enable (≥2.5V = ON); voltage ramp at this pin sets output slew rate - eliminates inrush current and stabilizes startup. |
| SYNC (6) | External Clock Input | Accepts 250kHz–2MHz clock for EMI reduction or synchronization with other converters - tied to GND for Burst Mode operation. |
| PG (7) | Power Good Flag | Open-collector output asserting high when VOUT ≥ 91% of target - used for system reset, sequencing, or fault monitoring. |
| FB (8) | Feedback Input | Regulated to 0.790V - connects to resistor divider tap - determines output voltage accuracy and loop stability. |
| VC (9) | Error Amplifier Output | Controls peak switch current - external RC compensation network here sets loop bandwidth and phase margin. |
| RT (10) | Frequency Set Resistor | Resistor to GND programs switching frequency from 200kHz to 2.4MHz - enables trade-off between size, efficiency, and dropout. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Boost Schottky Diode | Eliminates external boost diode, reducing BOM count and PCB area while ensuring optimal gate drive voltage for NPN saturation. |
| Low-Ripple Burst Mode Operation | Maintains <15mVP-P output ripple at light loads without sacrificing 75μA IQ - avoids audible noise and preserves regulation integrity. |
| Overvoltage Lockout (33V typ) | Disables switching before damage occurs during load dump or hot-swap events - protects downstream circuitry without external TVS clamping. |
| Thermally Enhanced Exposed Pad | Pin 11 (GND) requires PCB soldering - achieves θJA = 45°C/W, enabling 3.5A operation in compact layouts without forced air. |
| Synchronizable Switching | Accepts external clock from 250kHz to 2MHz - allows EMI spectrum spreading and multi-rail coherence in dense power systems. |
| Internal Bias Current Sourcing from VOUT | Draws regulator bias from BD pin when VOUT > 3V - improves light-load efficiency by avoiding VIN-derived quiescent loss. |
Applications
| Automotive Battery Regulation | Distributed Supply Regulation |
|---|---|
Use Scenario: Regulating 12V/24V vehicle battery rail to 3.3V or 5V for infotainment ECUs, ADAS cameras, or CAN transceivers under cold-crank (4.5V) and load-dump (62V) conditions. IC Role / Device Role / Timing Role: Primary buck controller providing isolated, stable, and transient-robust local power - manages start-up sequencing, overvoltage shutdown, and power-good signaling. Use Value: Eliminates need for pre-regulator stages; withstands 62V transients without external protection; maintains 75μA IQ for always-on modules. | Use Scenario: Generating multiple point-of-load voltages (e.g., 1.2V, 3.3V, 5V) from a shared 12V or 24V intermediate bus in programmable logic controllers or industrial I/O modules. IC Role / Device Role / Timing Role: High-current, thermally efficient buck stage delivering up to 3.5A per rail - synchronized via SYNC pin to reduce system-level EMI. Use Value: Enables compact, high-density power delivery with minimal thermal derating; supports RT-programmed frequencies to match magnetic availability. |
| Industrial Supplies | Wall Transformer Regulation |
Use Scenario: Replacing linear regulators or legacy buck ICs in DIN-rail mounted HMIs, motor drives, or process controllers where wide input range and reliability are mandatory. IC Role / Device Role / Timing Role: Main DC/DC converter handling 9–36V DC inputs - leverages thermal pad and current-mode control for stable operation in unventilated enclosures. Use Value: Delivers 3.5A at >90% efficiency across temperature; includes thermal shutdown and soft-start to prevent field failures during power cycling. | Use Scenario: Converting rectified AC wall adapter outputs (e.g., 12V–30V DC) to clean 3.3V/5V for IoT edge devices, smart meters, or battery-backed security sensors. IC Role / Device Role / Timing Role: Efficient, low-noise primary regulator operating in Burst Mode during standby - interfaces with battery charging circuitry via RUN/SS pin. Use Value: Achieves <1μA shutdown current and 75μA light-load IQ - extends battery backup time; PG flag enables graceful firmware suspend/resume. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT8610EMSE#TRPBF | 42V max input, 3.5A, 2.2MHz sync capability, 2.5μA IQ (Silent Switcher), no integrated boost diode | Superior EMI performance and lower IQ, but requires external bootstrap diode and higher BOM cost | Preferred for noise-sensitive applications (e.g., RF modules); less suitable where BD pin biasing from VOUT is needed for ultra-low-light-load efficiency. |
| TPS54332DRCT | 28V max input, 3.5A, fixed 1MHz, 145μA IQ, no PG flag or SYNC, SOIC-8 package | Lacks power good, synchronization, and thermal pad - simpler but less feature-rich and less robust in harsh environments | Cost-optimized alternative for non-automotive, non-safety-critical designs where footprint and feature count are secondary to unit price. |
Compared with LT8610EMSE#TRPBF and TPS54332DRCT, the LT3972IMSE#TRPBF uniquely combines 33V input, integrated boost diode, PG flag, SYNC, and 75μA Burst Mode IQ in a thermally optimized MSOP - making it the most balanced choice for automotive and industrial applications demanding reliability, integration, and thermal headroom.
Availability
LT3972IMSE#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 AEC-Q200-aligned reliability.
Supply support for LT3972IMSE#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) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving automotive, industrial, communications, and healthcare markets.
The LT3972 product line was designed specifically for wide-input, high-reliability DC/DC conversion in automotive and industrial environments - emphasizing transient robustness, thermal resilience, and integrated functionality to reduce system complexity.
FAQ
What is the maximum input voltage rating for LT3972IMSE#TRPBF, and how does overvoltage protection work?
The LT3972IMSE#TRPBF has an absolute maximum VIN rating of 62V for non-repetitive 1-minute transients, with continuous operation rated up to 33V. Its overvoltage lockout circuit disables switching when VIN exceeds ~33V (min 33V, typ 35V, max 37V), preventing damage while sustaining the 62V transient - a critical feature for automotive load-dump survival. During OVL, the output is unregulated but the device remains undamaged.
Does LT3972IMSE#TRPBF require an external boost diode, and what is the role of the BD pin?
No, the LT3972IMSE#TRPBF integrates the boost Schottky diode function internally - the BD pin connects only to the anode of the external boost capacitor (not a diode). The BD pin also supplies bias current to the internal regulator; when VOUT > 3V, the IC draws bias from BD, improving light-load efficiency. This eliminates the need for an external boost diode and simplifies layout.
How is soft-start implemented on LT3972IMSE#TRPBF, and can it be adjusted?
Soft-start on the LT3972IMSE#TRPBF is implemented via the RUN/SS pin: applying a controlled voltage ramp (e.g., using an RC network from VIN to RUN/SS) causes the output voltage to rise linearly, limiting inrush current. The ramp rate is determined by the RC time constant - typical values use 100kΩ and 100nF for ~10ms rise time. This prevents overshoot and stress on downstream capacitors and loads.
What package type and thermal characteristics apply to LT3972IMSE#TRPBF?
The LT3972IMSE#TRPBF uses a 10-lead MSOP package (MSE) with exposed thermal pad (Pin 11 = GND). Its thermal resistance is θJA = 45°C/W and θJC = 10°C/W when the exposed pad is properly soldered to a minimum 100mm² copper pour. This enables full 3.5A output at +125°C ambient without forced airflow - verified in Linear's demo circuit DC2222A.
Can LT3972IMSE#TRPBF synchronize to an external clock, and what is the valid frequency range?
Yes, the LT3972IMSE#TRPBF supports external synchronization via the SYNC pin, accepting TTL/CMOS-compatible clocks from 250kHz to 2MHz. Clock edges must have rise/fall times <1μs. When not used, SYNC must be tied to GND to enable low-ripple Burst Mode operation. Synchronization allows EMI reduction and multi-converter phase alignment in complex power systems.
LT3972IMSE#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
LT3972IMSE#TRPBF FAQ
1.How can I place an order for LT3972IMSE#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3972IMSE#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 LT3972IMSE#TRPBF reliable?
The price and inventory of LT3972IMSE#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3972IMSE#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3972IMSE#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3972IMSE#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3972IMSE#TRPBF?
LT3972IMSE#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3972IMSE#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 LT3972IMSE#TRPBF?
For technical support, including LT3972IMSE#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3972IMSE#TRPBF requirements.
6.How does Aetrix verify that LT3972IMSE#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3972IMSE#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 LT3972IMSE#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3972IMSE#TRPBF?
All LT3972IMSE#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3972IMSE#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 LT3972IMSE#TRPBF part is unused and in its original packaging.
Return procedure for LT3972IMSE#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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