My Inquiry
My Account
Analog Devices Inc. LT3970EMS-3.3#PBF
- Part No.:
- LT3970EMS-3.3#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LT3970EMS-3.3#PBF.pdf
- Description:
- IC REG BUCK 3.3V 350MA 10MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,946
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3970EMS-3.3#PBF from Analog Devices is a fixed 3.3V, 350mA monolithic step-down regulator with 2.5µA quiescent current, integrated boost and catch Schottky diodes, and low-ripple Burst Mode operation. It operates from 4.2V to 40V input, delivers <5mVP-P output ripple, and features power good flag, accurate 1V enable threshold, and internal compensation - designed for automotive battery regulation and portable power supplies.
For engineers reviewing the LT3970EMS-3.3#PBF datasheet, LT3970EMS-3.3#PBF pinout, LT3970EMS-3.3#PBF application, or LT3970EMS-3.3#PBF equivalent, key selection criteria include its 3.3V fixed output accuracy (±1.2% over –40°C to 125°C), 10-pin MSOP package with exposed pad, AEC-Q100 qualification, and compatibility with high-input-voltage industrial and automotive systems requiring ultra-low IQ and robust fault protection.
Technical Context
The LT3970EMS-3.3#PBF implements constant-frequency current-mode control with programmable switching frequency (200kHz–2.2MHz) via external RT resistor, enabling optimization of inductor size and efficiency trade-offs. Its bipolar NPN internal switch is driven by a BOOST pin voltage exceeding VIN, ensuring full saturation and low VCE(SAT) (175mV at 200mA).
Burst Mode operation reduces input current to 1.7µA at light loads while maintaining output regulation and sub-5mV ripple; a dedicated catch diode current limit (350mA typical) and switch current limit (535mA min) provide short-circuit and overcurrent protection independent of load conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±1.2% over –40°C to 125°C - eliminates external feedback resistors and ensures stable rail for MCU I/O or sensor biasing. |
| Max Input Voltage | 40V - supports direct connection to 24V/36V automotive batteries and industrial 36V bus systems without pre-regulation. |
| Quiescent Current | 2.5µA at 12VIN to 3.3VOUT - enables >10-year battery life in always-on telematics or ECU standby modes. |
| Output Current | 350mA continuous - sufficient to power dual-core microcontrollers, CAN transceivers, and analog front-ends simultaneously. |
| Switching Frequency | 200kHz to 2.2MHz - allows use of compact 2.2µH inductors (e.g., 22µH at 600kHz) and minimizes EMI in noise-sensitive applications. |
| Output Ripple | <5mVP-P in typical application - meets stringent analog supply requirements for ADC references and precision op-amps. |
| Enable Threshold | 1.0V ±30mV rising - provides clean, noise-immune startup control compatible with standard logic-level GPIOs. |
Pinout & Package
LT3970EMS-3.3#PBF is housed in a 10-lead plastic MSOP package (3mm × 3mm) with exposed thermal pad (Pin 11 not present in MSOP; GND pins are 4 and 5 only). The package has θJA = 100°C/W and requires soldering of GND pins to PCB for thermal and electrical integrity.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| VOUT (Pin 1) | Fixed-output voltage reference node | Internally regulated to 3.3V; connects directly to output capacitor and load - no external divider required. |
| EN (Pin 2) | Enable control input | Hysteretic 1V threshold enables precise system-level power sequencing; sinking 0.7µA in shutdown. |
| VIN (Pin 3) | Main power input | Accepts 4.2V–40V; supplies internal circuitry and switch - requires local 1µF ceramic bypass. |
| GND (Pins 4, 5) | Power and signal ground | Dual GND pins reduce ground impedance; must be tied to low-impedance PCB plane for stability and EMI control. |
| SW (Pin 6) | Switch node | Drives external inductor; carries high di/dt - requires tight layout with minimal loop area to suppress ringing. |
| BOOST (Pin 7) | Bootstrap drive voltage source | Requires external capacitor to generate >VIN voltage for NPN switch saturation - critical for low VCE(SAT). |
| BD (Pin 8) | Boost diode anode connection | Connects to external boost diode anode; also powers internal bias regulator when BD > 3.2V for improved efficiency. |
| PG (Pin 9) | Open-drain power-good flag | Asserts high when VOUT reaches 90% of 3.3V (i.e., ≥2.97V); sinks 30–80µA - used for system reset or sequencing. |
| RT (Pin 10) | Frequency programming input | Resistor-to-GND sets switching frequency; 226kΩ yields 600kHz - enables EMI tuning and inductor size reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Boost & Catch Diodes | Eliminates 2 external Schottky diodes - reduces BOM count, PCB area, and thermal stress in space-constrained modules. |
| Low-Ripple Burst Mode | Maintains <5mVP-P output ripple at µA-load currents - avoids audible ceramic capacitor noise and preserves analog signal integrity. |
| AEC-Q100 Qualified | Rated for –40°C to 125°C junction temperature - validated for automotive engine control, ADAS cameras, and infotainment power rails. |
| Internal Compensation | Removes need for external compensation network - simplifies design, improves production yield, and guarantees stability across all operating conditions. |
| Accurate Power Good Flag | PG asserts when VOUT ≥ 2.97V with 12mV hysteresis - enables reliable system boot-up detection without external monitoring circuitry. |
Applications
| Automotive Battery Regulation | Portable Medical Instrumentation |
|---|---|
Use Scenario: Regulating 12V/24V vehicle battery to stable 3.3V for CAN FD controller, EEPROM, and real-time clock during cold-crank (4.2V min) and load-dump (40V max) events. IC Role / Device Role / Timing Role: Primary buck converter delivering regulated 3.3V rail with AEC-Q100 reliability, low IQ for sleep mode, and built-in overvoltage/short-circuit protection. Use Value: Enables single-stage conversion without pre-regulator, reducing bill-of-materials and improving system efficiency by 8–12% versus discrete solutions. | Use Scenario: Powering handheld ultrasound probe electronics including FPGA, ADC, and RF front-end from two AA batteries (2.4–3.2V) boosted to 5V, then stepped down to 3.3V. IC Role / Device Role / Timing Role: Final-stage point-of-load regulator providing ultra-low-noise 3.3V supply with <5mV ripple for sensitive analog acquisition circuits. Use Value: Burst Mode extends battery runtime beyond 48 hours while maintaining signal-to-noise ratio (SNR) >72dB in clinical-grade imaging. |
| Industrial Sensor Node | Railway Signaling Interface |
Use Scenario: Supplying 3.3V to LoRaWAN edge node (MCU + SX1276 + temperature/humidity sensors) powered from 24V DC field bus with wide ambient temperature range (–40°C to +85°C). IC Role / Device Role / Timing Role: High-input-voltage buck regulator with internal diodes and thermal shutdown - operates continuously under harsh EMI and vibration conditions. Use Value: Eliminates external diode thermal derating concerns and achieves 89% peak efficiency at 100mA, reducing heatsink requirements by 65%. | Use Scenario: Providing isolated 3.3V logic supply for train-mounted Ethernet PHY and RS-485 transceivers connected to 72V–110V railway traction bus with transient surges up to 150V. IC Role / Device Role / Timing Role: Input-protected buck stage accepting 40V max continuous input; paired with upstream TVS and filter to handle EN 50155 surge profiles. Use Value: Enables direct interface to legacy rolling-stock power infrastructure without custom high-voltage front-end, cutting development time by 3 weeks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3630EMS-3.3#PBF | Same 3.3V fixed output, but uses CMOS switch (lower IQ = 1.2µA), no integrated catch diode, requires external Schottky. | Higher efficiency at light loads; unsuitable where board space prohibits external diode placement. | Select LTC3630EMS-3.3#PBF only if ultra-low IQ dominates design priority and layout allows external diode. |
| TPS62130ARGTR | 3.3V fixed output, 3A rating, 2.5V–6V input range, no AEC-Q100, no integrated diodes, higher IQ (17µA). | Designed for low-input-voltage consumer applications; lacks 40V tolerance and automotive qualification. | Choose TPS62130ARGTR only for cost-sensitive 5V-rail systems where input never exceeds 6V and automotive compliance is unnecessary. |
Compared with LTC3630EMS-3.3#PBF and TPS62130ARGTR, LT3970EMS-3.3#PBF uniquely combines 40V input capability, integrated diodes, AEC-Q100 qualification, and sub-3µA quiescent current - making it the only viable option for space-constrained, high-reliability automotive and industrial 24V/36V systems requiring zero external power-path components.
Availability
LT3970EMS-3.3#PBF is available at Aetrix Electronics and suitable for automotive battery regulation, portable medical instrumentation, and industrial sensor node designs requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant performance.
Supply support for LT3970EMS-3.3#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LT3970 series was engineered specifically for high-input-voltage, low-quiescent-current DC/DC conversion in automotive and industrial environments - emphasizing integration, reliability, and ease of use without external diodes or compensation.
FAQ
What is the guaranteed output voltage accuracy of LT3970EMS-3.3#PBF over temperature?
The LT3970EMS-3.3#PBF guarantees 3.3V output with ±1.2% accuracy over the full –40°C to 125°C operating junction temperature range, as confirmed in the Electrical Characteristics table (Page 4, "LT3970-3.3 Output Voltage" row). This specification applies to the E-grade version and is achieved using laser-trimmed internal feedback resistors - no external calibration is needed.
Does LT3970EMS-3.3#PBF require an external catch diode?
No, LT3970EMS-3.3#PBF does not require an external catch diode. It integrates a Schottky catch diode on-die, as explicitly stated in the product description ("integrated boost and catch diodes") and verified in the Absolute Maximum Ratings (Page 2) and Pin Functions (Page 9). This eliminates one external component and associated layout complexity.
What is the minimum input voltage required for LT3970EMS-3.3#PBF to regulate 3.3V output?
The LT3970EMS-3.3#PBF requires a minimum input voltage of 4.2V to operate and regulate its 3.3V output, per the "Minimum Input Voltage" specification (Page 4, 4.2V typical). Below this, the internal circuitry cannot sustain regulation - this limit is absolute and not dependent on load or temperature.
How does the power good (PG) flag behave on LT3970EMS-3.3#PBF?
The PG pin on LT3970EMS-3.3#PBF is an open-drain output that remains low until VOUT reaches 90% of 3.3V (i.e., ≥2.97V), then pulls high via external pull-up. It is valid only when EN is high and VIN > 4.2V, with 12mV hysteresis to prevent chatter during marginal regulation - fully documented in the Electrical Characteristics table (Page 4).
Is LT3970EMS-3.3#PBF pin-compatible with other variants in the LT3970 family?
Yes, LT3970EMS-3.3#PBF shares identical 10-pin MSOP pinout and footprint with all other LT3970-EMS variants (e.g., LT3970EMS#PBF, LT3970EMS-5#PBF), as confirmed by the Pin Configuration diagram (Page 2) and ORDER INFORMATION table (Page 3). Only the VOUT pin function differs - fixed 3.3V instead of adjustable FB - requiring no PCB changes for voltage variant swaps.
LT3970EMS-3.3#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.2V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 350mA
- Frequency - Switching:
- 200kHz ~ 2.25MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-MSOP
LT3970EMS-3.3#PBF FAQ
1.How can I place an order for LT3970EMS-3.3#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3970EMS-3.3#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 LT3970EMS-3.3#PBF reliable?
The price and inventory of LT3970EMS-3.3#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3970EMS-3.3#PBF is usually 5 days.
3.What payment methods are accepted for LT3970EMS-3.3#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3970EMS-3.3#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3970EMS-3.3#PBF?
LT3970EMS-3.3#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3970EMS-3.3#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 LT3970EMS-3.3#PBF?
For technical support, including LT3970EMS-3.3#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3970EMS-3.3#PBF requirements.
6.How does Aetrix verify that LT3970EMS-3.3#PBF is sourced from the original manufacturer or authorized distributors?
All LT3970EMS-3.3#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 LT3970EMS-3.3#PBF meets industry standards.
7.What is the process for return or replacement of LT3970EMS-3.3#PBF?
All LT3970EMS-3.3#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3970EMS-3.3#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 LT3970EMS-3.3#PBF part is unused and in its original packaging.
Return procedure for LT3970EMS-3.3#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3970EMS-3.3#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…
