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Texas Instruments LM3670MF-ADJ/NOPB
- Part No.:
- LM3670MF-ADJ/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM3670MF-ADJ/NOPB.pdf
- Description:
- IC REG BUCK ADJ 350MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,645
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Product details
Overview
LM3670MF-ADJ/NOPB from Texas Instruments is a miniature synchronous step-down DC-DC converter optimized for ultralow-voltage circuits powered by single Li-Ion or three-cell NiMH/NiCd batteries. It delivers up to 350 mA load current, supports adjustable output voltages from 0.7 V to 2.5 V via external resistor divider, operates with 1-MHz fixed-frequency PWM and automatic PFM mode switching, and achieves 94% typical efficiency at 10–100 mA loads - enabling compact, high-efficiency power rails in space-constrained portable electronics.
For engineers reviewing the LM3670MF-ADJ/NOPB datasheet, LM3670MF-ADJ/NOPB pinout, LM3670MF-ADJ/NOPB application, or LM3670MF-ADJ/NOPB equivalent, key selection considerations include its 5-pin SOT-23 package, 15 µA quiescent current in PFM mode, 0.1 µA shutdown current, internal synchronous rectification, and support for only three external components (inductor + two ceramic capacitors) - critical for battery life extension and PCB area minimization in handheld devices.
Technical Context
The LM3670MF-ADJ/NOPB implements voltage-mode control with input voltage feed-forward to maintain stable regulation across wide VIN (2.5 V to 5.5 V) and load (0–350 mA) ranges. Its dual-mode operation - fixed-frequency 1-MHz PWM above ~70 mA and hysteretic PFM below - dynamically optimizes efficiency versus noise trade-offs without external mode control.
Internal synchronous rectification uses integrated PFET and NFET switches (RDSON(P) = 360–690 mΩ, RDSON(N) = 250–660 mΩ), enabling >90% efficiency at light loads and supporting 100% duty-cycle low-dropout operation down to VIN ≈ VOUT + ILOAD × (RDSON(P) + RINDUCTOR). Soft-start limits inrush current, while undervoltage lockout (2.4 V) and thermal/overcurrent protection ensure robust system-level reliability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.5 V to 5.5 V - compatible with single Li-ion (2.7–4.2 V) and three-cell NiMH/NiCd (3.6 V nominal) battery sources. |
| Adjustable Output Range | 0.7 V to 2.5 V - set via external resistor divider on FB pin; enables precise rail generation for modern low-voltage logic and analog ICs. |
| Max Load Current | 350 mA - sufficient for powering core logic, RF front-ends, or display drivers in handheld devices without external boost stages. |
| Quiescent Current | 15 µA typical in PFM mode - extends battery runtime during standby/sleep states in always-on subsystems. |
| Switching Frequency | 1 MHz typical (550–1300 kHz range) - allows use of small 4.7–10 µH inductors and 4.7–10 µF ceramic capacitors, minimizing solution footprint. |
| Shutdown Current | 0.1 µA typical - ensures negligible battery drain when disabled via EN pin, critical for long-term storage or deep-sleep modes. |
| Efficiency | 94% typical at 10–100 mA (VIN = 3.6 V, VOUT = 1.8 V) - reduces thermal stress and extends usable battery capacity in thermally constrained enclosures. |
Pinout & Package
The LM3670MF-ADJ/NOPB is housed in a 5-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm, optimized for high-density portable PCB layouts and reflow-compatible assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Power Input | Connects to input filter capacitor (≥4.7 µF ceramic); accepts 2.5–5.5 V supply; powers internal bias and switch drivers. |
| GND (Pin 2) | Ground Reference | Primary return path for input/output currents and internal control circuitry; must be low-impedance connection to system ground plane. |
| EN (Pin 3) | Digital Enable | Active-high logic input (VIH ≥ 1.3 V, VIL ≤ 0.4 V); pulls low to enter 0.1 µA shutdown state; must not float. |
| FB (Pin 4) | Analog Feedback | Senses output voltage via external resistor divider; sets regulated VOUT = 0.5 V × (1 + R1/R2); tolerance includes divider accuracy. |
| SW (Pin 5) | Switching Node | Connects to inductor; carries high di/dt switching current (peak ≤ 750 mA); requires short, low-inductance trace to minimize EMI. |
Key Features
| Feature | Design Value |
|---|---|
| Automatic PWM/PFM Mode Switching | Eliminates manual mode control; transitions seamlessly between 1-MHz PWM (≥70 mA) and low-noise PFM (≤70 mA), optimizing efficiency across full load range. |
| Internal Synchronous Rectification | Integrates PFET high-side and NFET low-side switches - removes need for external Schottky diode, improves light-load efficiency by 5–10% vs. asynchronous designs. |
| 100% Duty-Cycle Low-Dropout Operation | Enables regulation down to VIN ≈ VOUT + ILOAD × (RDSON(P) + RINDUCTOR); maintains output stability as battery discharges below regulator headroom. |
| Internal Soft Start | Limit inrush current during startup; typical 400 µs rise time with 10 µF COUT and 350 mA load - prevents input rail sag and protects upstream power sources. |
| Overcurrent & Thermal Protection | Cycle-by-cycle current limiting (620 mA typical peak) and thermal shutdown prevent damage during short-circuit or overload events without external circuitry. |
Applications
| Mobile Phone Core Rail | Handheld Instrument ADC Supply |
|---|---|
Use Scenario: Powering ARM Cortex-M core and memory subsystems in slim smartphones operating from single Li-ion battery. IC Role / Device Role / Timing Role: Primary step-down regulator generating 1.2 V or 1.8 V core voltage with tight load transient response and minimal board area. Use Value: 94% efficiency at 100 mA reduces thermal dissipation in sealed enclosure; 15 µA PFM quiescent current extends standby time beyond 72 hours. | Use Scenario: Providing clean, low-noise 2.5 V analog supply for 16-bit SAR ADC in portable multimeter or data logger. IC Role / Device Role / Timing Role: Precision-adjustable buck converter delivering stable rail with <10 mV ripple under dynamic sensor excitation loads. Use Value: Internal synchronous rectification and 1-MHz switching enable small LC filter (10 µH + 10 µF) that meets ADC PSRR requirements without ferrite beads. |
| PDA Application Processor I/O | Wearable Sensor Hub Power |
Use Scenario: Generating configurable 1.5 V or 1.8 V I/O voltage for application processor in legacy PDA with multi-rail power architecture. IC Role / Device Role / Timing Role: Secondary buck regulator supporting dynamic voltage scaling (DVS) via FB resistor network reconfiguration. Use Value: Adjustable output range (0.7–2.5 V) and ±4.5% output tolerance allow safe margining for process variation across production batches. | Use Scenario: Supplying 0.9 V or 1.1 V to ultra-low-power MCU and BLE radio in coin-cell-powered fitness tracker. IC Role / Device Role / Timing Role: High-efficiency, low-quiescent-current DC-DC converter enabling >6-month battery life with daily sync. Use Value: 0.1 µA shutdown current and 15 µA PFM IQ minimize energy loss during 99%+ sleep duty cycle; SOT-23 footprint fits 8 mm × 8 mm module. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRVR | Fixed 1.8 V output only; 2.05–6.0 V input; 300 mA max; 3.6 MHz switching frequency; requires different external component values. | Lacks adjustable output - unsuitable where multiple rail voltages are needed from same BOM; higher fSW demands smaller inductor but increases EMI filtering complexity. | Select only if fixed 1.8 V is sufficient and board layout allows higher-frequency magnetics; verify thermal performance at 350 mA with 3.6 MHz switching. |
| AP3012KTR-G1 | Adjustable 1.25–28 V output; 2.5–5.5 V input; 300 mA max; 1.5 MHz fSW; no PFM mode - fixed PWM only. | Higher minimum VOUT (1.25 V) and no light-load efficiency optimization - less suitable for sub-1 V logic or extended battery standby. | Prefer where cost sensitivity outweighs light-load efficiency; confirm FB divider stability and transient response meet system requirements without PFM hysteresis. |
Compared with TPS62231DRVR and AP3012KTR-G1, the LM3670MF-ADJ/NOPB uniquely combines adjustable sub-1 V capability, 15 µA PFM IQ, and 100% duty-cycle dropout - making it the only option among the three qualified for ultralow-voltage, battery-life-critical portable applications requiring design flexibility.
Availability
LM3670MF-ADJ/NOPB is available at Aetrix Electronics and suitable for mobile phones, handheld instruments, and wearable sensor hubs requiring stable component supply, long-lifecycle availability, and consistent parametric performance across production lots.
Supply support for LM3670MF-ADJ/NOPB 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
Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in power management ICs for portable, industrial, and automotive markets.
The LM3670 product line was designed specifically for ultralow-voltage, high-efficiency DC-DC conversion in battery-powered handheld devices - emphasizing minimal external component count, low quiescent current, and robust protection features for consumer-grade reliability.
FAQ
What is the minimum input voltage required for LM3670MF-ADJ/NOPB to regulate a 0.9 V output at 200 mA?
The minimum input voltage depends on dropout: VIN_MIN = VOUT + ILOAD × (RDSON(P) + RINDUCTOR). With RDSON(P) = 690 mΩ max and typical inductor DCR < 0.1 Ω, VIN_MIN ≈ 0.9 V + 0.2 A × 0.79 Ω = 1.06 V - but per datasheet, absolute minimum VIN is 2.5 V. So LM3670MF-ADJ/NOPB requires ≥2.5 V input regardless of load; regulation is guaranteed only within 2.5–5.5 V VIN range.
Can LM3670MF-ADJ/NOPB be used with a 2.2 µH inductor instead of the recommended 4.7–10 µH?
Using 2.2 µH violates the design guidance: lower inductance increases peak switch current and ripple, risking saturation and exceeding the 750 mA peak limit. At 1 MHz, 2.2 µH yields higher IPP than 4.7 µH - potentially triggering overcurrent protection or reducing efficiency. TI recommends 4.7 µH or 10 µH; 2.2 µH is not validated for LM3670MF-ADJ/NOPB.
Does LM3670MF-ADJ/NOPB require an external compensation network?
No. LM3670MF-ADJ/NOPB integrates full frequency compensation - no external RC network is needed. The internal compensation is optimized for stability with standard 4.7 µF input and 10 µF output ceramic capacitors and typical 4.7–10 µH inductors, simplifying layout and reducing BOM count.
How does the FB pin tolerance affect output accuracy of LM3670MF-ADJ/NOPB?
The FB pin references an internal 0.5 V bandgap (VREF = 0.5 V ±2.5%). With VOUT = VREF × (1 + R1/R2), total output error includes resistor tolerance, tempco, and VREF error. For 1% resistors and 0.5 V reference, typical VOUT error is ±4.5% - confirmed in datasheet Table 6.5 for adjustable versions.
Is LM3670MF-ADJ/NOPB RoHS-compliant and lead-free?
Yes. The /NOPB suffix explicitly denotes lead-free and RoHS-compliant packaging. LM3670MF-ADJ/NOPB meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1) and is qualified for Pb-free reflow soldering per IPC/JEDEC J-STD-020.
LM3670MF-ADJ/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- 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):
- 2.5V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.7V
- Voltage - Output (Max):
- 5.5V
- Current - Output:
- 350mA
- Frequency - Switching:
- 1MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LM3670MF-ADJ/NOPB FAQ
1.How can I place an order for LM3670MF-ADJ/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3670MF-ADJ/NOPB 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 LM3670MF-ADJ/NOPB reliable?
The price and inventory of LM3670MF-ADJ/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3670MF-ADJ/NOPB is usually 5 days.
3.What payment methods are accepted for LM3670MF-ADJ/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3670MF-ADJ/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3670MF-ADJ/NOPB?
LM3670MF-ADJ/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3670MF-ADJ/NOPB 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 LM3670MF-ADJ/NOPB?
For technical support, including LM3670MF-ADJ/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3670MF-ADJ/NOPB requirements.
6.How does Aetrix verify that LM3670MF-ADJ/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3670MF-ADJ/NOPB 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 LM3670MF-ADJ/NOPB meets industry standards.
7.What is the process for return or replacement of LM3670MF-ADJ/NOPB?
All LM3670MF-ADJ/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3670MF-ADJ/NOPB, 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 LM3670MF-ADJ/NOPB part is unused and in its original packaging.
Return procedure for LM3670MF-ADJ/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3670MF-ADJ/NOPB Tags
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