My Inquiry
My Account
Analog Devices Inc. LT3971EDD-3.3#TRPBF
- Part No.:
- LT3971EDD-3.3#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 10-WFDFN Exposed Pad
- Datasheet:
-
LT3971EDD-3.3#TRPBF.pdf
- Description:
- IC REG BUCK 3.3V 1.2A 10DFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,920
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3971EDD-3.3#TRPBF from Analog Devices (formerly Linear Technology) is a fixed-output 3.3V, 1.2A monolithic buck switching regulator in a thermally enhanced 10-lead (3mm × 3mm) DFN package. It operates from 4.3V to 38V input, delivers ultralow 2.8µA quiescent current in regulation, and maintains <15mVP-P output ripple via low-ripple Burst Mode® operation - ideal for automotive battery-powered systems requiring long standby life.
For engineers reviewing the LT3971EDD-3.3#TRPBF datasheet, LT3971EDD-3.3#TRPBF pinout, LT3971EDD-3.3#TRPBF application, or LT3971EDD-3.3#TRPBF equivalent, key selection criteria include its fixed 3.3V output, 2.8µA no-load IQ, 1.2A continuous output capability, internal 10MΩ feedback divider, and exposed-pad DFN thermal performance at –40°C to 125°C junction temperature.
Technical Context
The LT3971EDD-3.3#TRPBF implements constant-frequency current-mode control with internal compensation and a 0.33Ω bipolar NPN power switch. Its architecture integrates a boost Schottky diode driver, soft-start (SS) ramp generator, and open-drain power-good (PG) flag that asserts when VOUT reaches 91% of nominal.
Burst Mode® operation reduces input supply current to 1.7µA during sleep cycles while maintaining tight regulation; frequency foldback below 200kHz occurs during startup or overload to limit peak inductor current. The device supports external synchronization (SYNC pin) but requires grounding for optimal low-IQ performance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±1.5% over –40°C to 125°C; internally trimmed 10MΩ divider eliminates external resistors. |
| Input Voltage Range | 4.3V to 38V; minimum start-up voltage is 4.3V, enabling direct connection to 12V/24V automotive batteries. |
| No-Load Quiescent Current | 2.8µA at 12VIN → 3.3VOUT; enables >10-year battery life in always-on IoT sensors. |
| Max Output Current | 1.2A continuous; limited by internal 2.4A switch current threshold and thermal design in DFN package. |
| Output Ripple | <15mVP-P in typical application; achieved via low-ripple Burst Mode® with controlled pulse energy. |
| Switching Frequency | Adjustable 200kHz–2MHz via RT resistor; fixed 800kHz in reference design; supports synchronization to external clock. |
| Enable Threshold | 1.01V rising-edge threshold with 30mV hysteresis; allows clean shutdown with standard logic-level signals. |
Pinout & Package
LT3971EDD-3.3#TRPBF uses a 10-lead (3mm × 3mm) plastic DFN package with exposed thermal pad (Pin 11) soldered to PCB ground for θJA = 45°C/W. Pin numbering follows top-view standard: Pin 1 = BD, Pin 2 = BOOST, Pin 3 = SW, Pin 4 = VIN, Pin 5 = EN, Pin 6 = VOUT, Pin 7 = SS, Pin 8 = RT, Pin 9 = PG, Pin 10 = SYNC, Pin 11 = GND (exposed pad).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BD (Pin 1) | Boost diode anode connection | Connects to cathode of external Schottky diode; forms charge pump path for BOOST drive voltage. |
| BOOST (Pin 2) | Internal switch gate drive supply | Must be biased ≥1.4V above SW to fully saturate bipolar NPN switch; requires external capacitor to VIN. |
| SW (Pin 3) | Switch node | Drives external inductor and catch diode; carries high di/dt; requires tight layout to minimize EMI. |
| VIN (Pin 4) | Main power input | Supplies IC bias and switch current; requires local 10µF ceramic bypass capacitor near pin. |
| EN (Pin 5) | Enable control input | Hysteretic 1.01V enable threshold; pulls device into 700nA shutdown state when low. |
| VOUT (Pin 6) | Regulated output | Fixed 3.3V output; connects directly to load; internal 10MΩ divider sets voltage without external resistors. |
| SS (Pin 7) | Soft-start timing | Capacitor to GND controls inrush current ramp rate; discharges only during EN low. |
| RT (Pin 8) | Frequency programming | Resistor to GND sets switching frequency from 200kHz to 2MHz per datasheet table. |
| PG (Pin 9) | Power-good flag | Open-drain output active-low until VOUT reaches 91% of 3.3V; requires external pull-up. |
| SYNC (Pin 10) | External clock input | Ground for Burst Mode®; tie to external clock (250kHz–2MHz) for synchronized operation. |
Key Features
| Feature | Design Value |
|---|---|
| Ultralow quiescent current | 2.8µA IQ in regulation enables >10-year battery life in always-on automotive telematics modules. |
| Low-ripple Burst Mode® | Maintains <15mVP-P output ripple at light loads while achieving 85%+ efficiency down to 100µA output current. |
| Integrated 10MΩ feedback divider | Eliminates external resistors for 3.3V output, reducing BOM count and improving accuracy vs. external divider drift. |
| Thermally enhanced DFN | 3mm × 3mm exposed-pad package achieves θJA = 45°C/W, supporting 1.2A continuous output at 85°C ambient. |
| Accurate power-good flag | PG asserts when VOUT reaches 3.003V (91% of 3.3V); provides system-level power sequencing confirmation. |
Applications
| Automotive Body Control Module (BCM) | Industrial IoT Sensor Node |
|---|---|
Use Scenario: Powering microcontroller, CAN transceiver, and wake-up circuitry in vehicle door modules with 12V battery input. IC Role / Device Role / Timing Role: Primary 3.3V buck regulator delivering stable rail during cold-crank (4.3V min) and load-dump transients (up to 38V). Use Value: 2.8µA quiescent current prevents battery drain during multi-year vehicle standby; PG flag enables safe MCU boot sequencing. | Use Scenario: Supplying ultra-low-power ARM Cortex-M0+ MCU and sub-GHz RF transceiver in battery-operated predictive maintenance sensor. IC Role / Device Role / Timing Role: Fixed 3.3V step-down converter operating in Burst Mode® during 99% sleep duty cycle. Use Value: Enables >15-year coin-cell battery life; <15mV ripple ensures clean ADC reference and RF PLL stability. |
| Portable Medical Diagnostic Device | Railway Signaling Interface |
Use Scenario: Powering precision analog front-end (AFE), display driver, and Bluetooth LE radio in handheld ECG monitor. IC Role / Device Role / Timing Role: Main 3.3V supply with soft-start (SS pin) preventing inrush-induced brownout on Li-ion battery startup. Use Value: Internal compensation eliminates loop-stability tuning; 1.2A rating supports simultaneous AFE + BLE burst transmission. | Use Scenario: Converting 72V DC traction supply to isolated 3.3V logic rail for train communication gateway controller. IC Role / Device Role / Timing Role: Input-stage buck regulator accepting wide 4.3V–38V range, followed by isolated DC/DC for safety compliance. Use Value: 38V absolute max input withstands 72V rail transients via external pre-regulator; PG flag validates upstream supply integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3630EMS8E-3.3#TRPBF | 40V input, 1A output, 1.5µA IQ, MSOP-8 package; no integrated boost diode driver. | Lacks BD/BOOST pins; requires external Schottky diode and bootstrap capacitor; smaller footprint but lower current. | Select when 1A output suffices and board space is constrained; verify external diode leakage <1µA for low-IQ performance. |
| TPS62840DRVR | 6V input max, 1A output, 0.12µA IQ, 2.5MHz sync-capable; no BD/BOOST, no PG flag. | Not suitable for automotive 12V/24V inputs; optimized for single-cell Li-ion; lacks power-good signaling. | Choose only for low-voltage portable applications where 38V input tolerance is unnecessary and nanoscale IQ is critical. |
Compared with LTC3630EMS8E-3.3#TRPBF and TPS62840DRVR, LT3971EDD-3.3#TRPBF uniquely combines 38V input tolerance, integrated boost driver, PG flag, and 1.2A output in a thermally robust DFN - making it the sole option for automotive and industrial 12V/24V systems demanding full feature integration and long-term reliability.
Availability
LT3971EDD-3.3#TRPBF is available at Aetrix Electronics and suitable for automotive body electronics, industrial IoT sensor nodes, and portable medical diagnostics requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LT3971EDD-3.3#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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, formed through the acquisition of Linear Technology in 2017.
The LT3971 product line was designed specifically for high-input-voltage, ultralow-quiescent-current DC/DC conversion in automotive, industrial, and battery-powered systems where reliability under wide temperature and input voltage extremes is mandatory.
FAQ
What is the guaranteed output voltage accuracy of the LT3971EDD-3.3#TRPBF over temperature?
The LT3971EDD-3.3#TRPBF guarantees 3.3V output within ±1.5% over the full –40°C to 125°C junction temperature range, as confirmed by electrical characteristics tables showing 3.25V to 3.35V min/max limits at temperature extremes. This accuracy is achieved via laser-trimmed internal 10MΩ feedback resistors, eliminating drift from external components.
Can the LT3971EDD-3.3#TRPBF operate from a 42V input source?
No - the LT3971EDD-3.3#TRPBF has an absolute maximum VIN rating of 38V. Applying 42V exceeds this limit and risks permanent damage. For 42V systems, use an external pre-regulator or select a higher-voltage-rated part such as the LT3999. Always observe the 38V absolute max to ensure long-term reliability of the LT3971EDD-3.3#TRPBF.
Does the LT3971EDD-3.3#TRPBF require external feedback resistors to set the 3.3V output?
No - the LT3971EDD-3.3#TRPBF integrates a precision 10MΩ internal feedback divider that fixes the output at 3.3V. Pin 6 is labeled VOUT (not FB), and no external resistors are needed. This simplifies layout, improves accuracy, and eliminates resistor drift effects - a key differentiator from adjustable versions like the base LT3971.
How does the power-good (PG) flag behave during startup of the LT3971EDD-3.3#TRPBF?
The PG pin of the LT3971EDD-3.3#TRPBF remains low until VOUT reaches 91% of 3.3V (i.e., 3.003V), then transitions high via open-drain output. It is valid only when EN is high and VIN > 4.3V. During soft-start (SS pin ramp), PG stays low until regulation is established - providing precise system-level power sequencing for MCUs or FPGAs powered by the LT3971EDD-3.3#TRPBF.
What thermal derating applies to the LT3971EDD-3.3#TRPBF at 100°C ambient temperature?
At 100°C ambient, the LT3971EDD-3.3#TRPBF's 1.2A rated output must be derated due to thermal limits. With θJA = 45°C/W and max TJ = 125°C, allowable temperature rise is 25°C, limiting power dissipation to ~0.56W. Accounting for typical 85% efficiency at 3.3V/1.2A, output current should be reduced to approximately 0.95A to maintain safe junction temperature - verified using thermal simulation or bench testing of the actual PCB layout for the LT3971EDD-3.3#TRPBF.
LT3971EDD-3.3#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 10-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.3V
- Voltage - Input (Max):
- 38V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 1.2A
- Frequency - Switching:
- 200kHz ~ 2MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-DFN (3x3)
LT3971EDD-3.3#TRPBF FAQ
1.How can I place an order for LT3971EDD-3.3#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3971EDD-3.3#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 LT3971EDD-3.3#TRPBF reliable?
The price and inventory of LT3971EDD-3.3#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3971EDD-3.3#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3971EDD-3.3#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3971EDD-3.3#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3971EDD-3.3#TRPBF?
LT3971EDD-3.3#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3971EDD-3.3#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 LT3971EDD-3.3#TRPBF?
For technical support, including LT3971EDD-3.3#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3971EDD-3.3#TRPBF requirements.
6.How does Aetrix verify that LT3971EDD-3.3#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3971EDD-3.3#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 LT3971EDD-3.3#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3971EDD-3.3#TRPBF?
All LT3971EDD-3.3#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3971EDD-3.3#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 LT3971EDD-3.3#TRPBF part is unused and in its original packaging.
Return procedure for LT3971EDD-3.3#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3971EDD-3.3#TRPBF 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…
