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Texas Instruments LM3670MF-1.8/NOPB
- Part No.:
- LM3670MF-1.8/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM3670MF-1.8/NOPB.pdf
- Description:
- IC REG BUCK 1.8V 350MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,401
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Product details
Overview
LM3670MF-1.8/NOPB from Texas Instruments is a fixed-output 1.8 V synchronous step-down DC-DC converter optimized for ultralow-voltage portable systems powered by single Li-Ion or three-cell NiMH/NiCd batteries. It delivers up to 350 mA load current, operates from 2.5 V to 5.5 V input, features 1-MHz PWM switching, automatic PFM/PWM mode transition, and internal soft start - enabling compact power rails in mobile phones and handheld instrumentation.
For engineers reviewing the LM3670MF-1.8/NOPB datasheet, LM3670MF-1.8/NOPB pinout, LM3670MF-1.8/NOPB application, or LM3670MF-1.8/NOPB equivalent, key selection criteria include its 1.8 V fixed output tolerance (±4.5% over 0–350 mA), 15 µA typical quiescent current in PFM mode, 0.1 µA shutdown current, SOT-23-5 package footprint, and compatibility with only three external components: one inductor and two ceramic capacitors.
Technical Context
The LM3670MF-1.8/NOPB implements voltage-mode control with input voltage feed-forward to maintain stable regulation across line and load variations. Its integrated PFET/NFET synchronous rectifier enables high efficiency (90–94% at 1–100 mA) without an external diode, while the 100% duty-cycle LDO mode supports operation down to VIN ≈ VOUT + ILOAD × (RDS(ON)P + RINDUCTOR).
It autonomously transitions between PWM (≥70 mA), PFM (light-load, ~15 µA IQ), and shutdown (<0.1 µA) modes based on inductor current discontinuity and peak-switch-current thresholds. The FB pin is internally tied to the 0.5 V reference for fixed 1.8 V output, eliminating external resistor dividers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.8 V ±4.5% over 0–350 mA load and −40°C to +125°C junction temperature |
| Input Voltage Range | 2.5 V to 5.5 V - supports single Li-Ion (2.7–4.2 V) and three-cell NiMH/NiCd (3.0–4.5 V) battery inputs |
| Max Load Current | 350 mA - sustained output capability with thermal derating above +85°C ambient |
| Switching Frequency | 1 MHz typical (550–1300 kHz range) - enables use of small 4.7–10 µH inductors and low-ESR ceramic capacitors |
| Quiescent Current | 15 µA typical in PFM mode - extends battery life during standby/sleep states in portable devices |
| Shutdown Current | 0.1 µA typical - minimizes battery drain when EN pin is pulled low |
| Efficiency | 94% typical at 10–100 mA (VIN = 3.6 V, VOUT = 1.8 V) - reduces thermal load and extends runtime |
| Package | SOT-23-5 (DBV), 2.90 mm × 1.60 mm - surface-mount compatible with high-density PCB layouts |
Pinout & Package
SOT-23-5 (DBV) package: 2.90 mm × 1.60 mm body, 0.95 mm height, gull-wing leads, RoHS-compliant, moisture sensitivity level 1.
| 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 PFET switch |
| GND (Pin 2) | Ground reference | Primary return path for input capacitor, inductor, and internal circuitry; must be low-impedance connection to PCB ground plane |
| EN (Pin 3) | Digital enable | Active-high logic input; ≥1.3 V enables operation, ≤0.4 V disables output and enters 0.1 µA shutdown state |
| FB (Pin 4) | Feedback node | Internally connected to 0.5 V reference for fixed 1.8 V output; no external resistors required |
| SW (Pin 5) | Switching node | Drives external inductor; connects to internal PFET drain and NFET source; requires low-inductance layout to minimize EMI |
Key Features
| Feature | Design Value |
|---|---|
| Internal synchronous rectification | Eliminates external Schottky diode, improving efficiency by 5–10% vs. asynchronous buck at 1.8 V output |
| Automatic PFM/PWM mode switching | Maintains >90% efficiency from 1 mA to 350 mA without manual mode control or external circuitry |
| 100% duty-cycle LDO operation | Enables regulation down to VIN = VOUT + ILOAD × (360–690 mΩ PFET RDS(ON) + inductor DCR), critical near battery end-of-life |
| Integrated soft-start | 400 µs typical startup time with 10 µF output capacitor - prevents inrush current and output overshoot |
| Current-limit and thermal protection | 750 mA peak switch current limit and thermal shutdown prevent damage during overload or poor heatsinking |
| Only three external components | Reduces BOM count and board area: 1 inductor (4.7–10 µH), 1 input cap (4.7 µF), 1 output cap (10 µF) |
Applications
| Mobile Phone Core Power Rail | Handheld Medical Instrumentation |
|---|---|
Use Scenario: Supplying 1.8 V core voltage to baseband processors and RF transceivers in slim-profile smartphones operating from a single Li-Ion cell. IC Role / Device Role / Timing Role: Primary step-down regulator delivering regulated 1.8 V with fast transient response to handle burst-mode processor loads. Use Value: 94% efficiency at 100 mA and 15 µA quiescent current in PFM extend talk time by >12% versus older linear regulators under mixed active/standby usage. | Use Scenario: Powering low-noise analog front-ends and microcontrollers in portable blood glucose meters and pulse oximeters. IC Role / Device Role / Timing Role: Fixed-output DC-DC converter providing clean, stable 1.8 V rail isolated from battery voltage sag during measurement cycles. Use Value: Internal soft-start and <1.8 V output tolerance ensure reliable MCU boot and ADC reference stability without external supervision circuitry. |
| PDA Application Processor Core | Battery-Powered Industrial Sensor Node |
Use Scenario: Generating 1.8 V for ARM-based application processors in legacy PDAs with tight space constraints and multi-day battery life targets. IC Role / Device Role / Timing Role: Compact synchronous buck converter supporting dynamic voltage scaling and deep-sleep modes via EN pin control. Use Value: 0.1 µA shutdown current and SOT-23-5 footprint allow integration into sub-20 mm² power sections without compromising runtime or layout density. | Use Scenario: Powering ultra-low-power microcontrollers and wireless transceivers (e.g., BLE, LoRa) in remote environmental sensors deployed for years on coin cells or small Li-SOCl₂ batteries. IC Role / Device Role / Timing Role: Efficient step-down regulator converting 3.6 V battery to 1.8 V system rail, synchronized with sensor sampling intervals to minimize average current draw. Use Value: PFM mode's 15 µA IQ and automatic wake-up on load increase eliminate need for external power gating, simplifying firmware and reducing component count. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down DC-DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRYR | 1.8 V fixed, 300 mA max, 3.6 MHz switching, 2.05 V min input, 3.6 µA IQ in PFM | Higher frequency allows smaller inductors but lower max current and narrower input range | Prefer for space-constrained designs needing <1 mm height inductors; avoid if >300 mA load or <2.5 V input is required |
| AP3012KTR-G1 | 1.8 V fixed, 300 mA max, 1.5 MHz switching, 2.5 V min input, 40 µA IQ in PFM | Higher quiescent current reduces light-load battery life; no 100% duty-cycle mode | Acceptable for cost-sensitive, non-battery-critical applications; not suitable for end-of-battery-life operation |
Compared with TPS62231DRYR and AP3012KTR-G1, the LM3670MF-1.8/NOPB offers higher load capability (350 mA), true 100% duty-cycle LDO support for extended battery life, and lower PFM quiescent current (15 µA), making it optimal for long-runtime portable devices with variable input voltage.
Availability
LM3670MF-1.8/NOPB is available at Aetrix Electronics and suitable for mobile phones, handheld medical instruments, PDAs, and battery-powered industrial sensor nodes requiring stable component supply, long-lifecycle availability, and consistent parametric performance across production batches.
Supply support for LM3670MF-1.8/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 headquartered in Dallas, Texas, designing and manufacturing analog ICs, embedded processors, and digital signal processors for industrial, automotive, and consumer markets.
The LM3670 product line was developed specifically for ultralow-voltage portable electronics, delivering high-efficiency, minimal-component DC-DC conversion from single-cell battery sources - targeting design simplicity, small footprint, and extended battery runtime.
FAQ
What is the output voltage accuracy of the LM3670MF-1.8/NOPB over full load and temperature?
The LM3670MF-1.8/NOPB provides a fixed 1.8 V output with ±4.5% tolerance across 0–350 mA load current and −40°C to +125°C junction temperature. This specification includes initial accuracy, line regulation (0.26%/V), and load regulation (0.0014%/mA), ensuring stable core voltage for sensitive digital loads without external trimming. The LM3670MF-1.8/NOPB achieves this using an internal 0.5 V reference and precision feedback network calibrated at wafer test.
Can the LM3670MF-1.8/NOPB operate with input voltage below 2.5 V?
No - the absolute minimum recommended input voltage for the LM3670MF-1.8/NOPB is 2.5 V per TI's Recommended Operating Conditions. Below this, undervoltage lockout (UVLO) disables regulation to protect internal circuitry. However, in 100% duty-cycle LDO mode, the LM3670MF-1.8/NOPB can sustain output as VIN drops to approximately VOUT + ILOAD × (RDS(ON)P + RINDUCTOR), provided VIN remains ≥2.5 V. The LM3670MF-1.8/NOPB will not function reliably below 2.4 V VIN.
What external components are required to use the LM3670MF-1.8/NOPB?
The LM3670MF-1.8/NOPB requires exactly three external components: a 4.7 µF ceramic input capacitor (CIN), a 10 µH inductor (L1) rated for ≥750 mA saturation current, and a 10 µF ceramic output capacitor (COUT). No feedback resistors are needed because the LM3670MF-1.8/NOPB is factory-trimmed for fixed 1.8 V output. All capacitors must be X5R/X7R dielectric with low ESR to ensure stability and low ripple.
How does the LM3670MF-1.8/NOPB manage efficiency across varying load conditions?
The LM3670MF-1.8/NOPB uses automatic mode switching: PWM mode (≥70 mA) delivers up to 94% efficiency at 10–100 mA; PFM mode (<70 mA) reduces quiescent current to 15 µA typical, maintaining >90% efficiency down to 1 mA; shutdown mode (<0.1 µA) eliminates static loss. This adaptive behavior is implemented entirely within the LM3670MF-1.8/NOPB's control logic - no external signals or configuration are required to optimize efficiency across sleep, active, and burst-load states.
Is the LM3670MF-1.8/NOPB pin-compatible with other variants in the LM3670 family?
Yes - all LM3670 variants (e.g., LM3670MF-1.2/NOPB, LM3670MF-1.5/NOPB, LM3670MF-3.3/NOPB, and adjustable LM3670SD-ADJ/NOPB) share identical SOT-23-5 (DBV) packaging and pinout (VIN, GND, EN, FB, SW). The LM3670MF-1.8/NOPB can be substituted for other fixed-output versions in existing layouts, though output voltage and load capability must be verified against system requirements. Feedback network changes are unnecessary since FB is internally configured.
LM3670MF-1.8/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:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.5V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- 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-1.8/NOPB FAQ
1.How can I place an order for LM3670MF-1.8/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3670MF-1.8/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-1.8/NOPB reliable?
The price and inventory of LM3670MF-1.8/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-1.8/NOPB is usually 5 days.
3.What payment methods are accepted for LM3670MF-1.8/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3670MF-1.8/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3670MF-1.8/NOPB?
LM3670MF-1.8/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3670MF-1.8/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-1.8/NOPB?
For technical support, including LM3670MF-1.8/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3670MF-1.8/NOPB requirements.
6.How does Aetrix verify that LM3670MF-1.8/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3670MF-1.8/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-1.8/NOPB meets industry standards.
7.What is the process for return or replacement of LM3670MF-1.8/NOPB?
All LM3670MF-1.8/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3670MF-1.8/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-1.8/NOPB part is unused and in its original packaging.
Return procedure for LM3670MF-1.8/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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