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Texas Instruments LM3670MF-1.5
- Part No.:
- LM3670MF-1.5
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM3670MF-1.5.pdf
- Description:
- IC REG BUCK 1.5V 350MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,127
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Product details
Overview
LM3670MF-1.5 from Texas Instruments is a fixed-output 1.5 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, 15 µA quiescent current in PFM mode, and internal soft start. It is used in mobile phone core logic rails and handheld device SoC power domains.
For engineers reviewing the LM3670MF-1.5 datasheet, LM3670MF-1.5 pinout, LM3670MF-1.5 application, or LM3670MF-1.5 equivalent, key selection criteria include output voltage accuracy (±5% over 0–350 mA), shutdown current (0.1 µA typical), thermal performance in SOT-23 (RθJA = 163.3°C/W), and compatibility with 4.7 µF input / 10 µF output ceramic capacitors and 4.7–10 µH inductors.
Technical Context
The LM3670MF-1.5 employs voltage-mode control with input voltage feed-forward to maintain stable regulation across line and load variations. Its dual-mode operation-fixed-frequency 1-MHz PWM above ~70 mA and hysteretic PFM below-enables high efficiency (94% at 10 mA) and ultra-low quiescent current (15 µA typical) simultaneously.
Internal synchronous rectification uses complementary PFET/NFET switches with RDS(on) of 360–690 mΩ (P) and 250–660 mΩ (N), enabling >90% efficiency from 1 mA to 100 mA. The 100% duty-cycle LDO mode supports dropout down to VOUT + ILOAD × (RDS(on,P) + RINDUCTOR), critical for battery end-of-life operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.5 V ±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 full operation from single Li-Ion (2.7–4.2 V) or three NiMH (3.0–4.5 V) |
| Max Load Current | 350 mA - sufficient for ARM Cortex-M cores, LPDDR memory I/O, and baseband processors |
| Quiescent Current | 15 µA typical in PFM mode - extends battery runtime during standby/sleep states |
| Shutdown Current | 0.1 µA typical - enables system-level power gating without leakage penalty |
| Switching Frequency | 1 MHz typical in PWM mode - allows use of tiny 4.7–10 µH shielded inductors & low-ESR ceramic caps |
| Efficiency | 94% at 10 mA, 92% at 300 mA (VIN = 3.6 V, VOUT = 1.5 V) - minimizes thermal rise in confined PCB areas |
Pinout & Package
The LM3670MF-1.5 is housed in a 5-pin SOT-23 package (2.90 mm × 1.60 mm body size), optimized for space-constrained portable PCBs and compatible with standard reflow profiles.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Power input | Connects to input filter capacitor (4.7 µF ceramic); must withstand 6 V absolute max and supply peak switch current |
| GND (Pin 2) | Ground reference | Primary return path for PFET/NFET switches and feedback network; requires low-inductance layout to minimize noise |
| EN (Pin 3) | Digital enable | Active-high logic input (VIH ≥1.3 V, VIL ≤0.4 V); pulls to GND to achieve 0.1 µA shutdown current |
| FB (Pin 4) | Feedback sense | Monitors output voltage via internal 0.5 V reference; unused in fixed-output LM3670MF-1.5 (internally tied) |
| SW (Pin 5) | Switching node | Drives external inductor; carries high di/dt current (peak 750 mA); requires short, wide trace to minimize EMI |
Key Features
| Feature | Design Value |
|---|---|
| Automatic PWM/PFM mode switching | Enables seamless transition between high-efficiency light-load (15 µA IQ) and low-noise full-power (1 MHz) operation |
| Internal synchronous rectification | Eliminates external Schottky diode, reducing BOM count and improving efficiency by 8–12% vs. asynchronous buck |
| 100% duty-cycle LDO mode | Maintains regulated 1.5 V output even as input drops to ~1.65 V (at 100 mA), extending usable battery life |
| Integrated soft-start | Limit in-rush current during startup; typical 400 µs ramp time with 10 µF output cap prevents input rail sag |
| Current-limit & thermal protection | 620 mA typical peak-switch current limit and thermal shutdown prevent damage during overload or poor heatsinking |
Applications
| Mobile Phone Core Rail | Wearable Sensor Hub Power |
|---|---|
Use Scenario: Powers ARM Cortex-M4F application processor core (VDD_CORE) in LTE smartphone during active and sleep cycles. IC Role / Device Role / Timing Role: Primary step-down regulator delivering stable 1.5 V at up to 350 mA with <50 mV load transient deviation. Use Value: Enables 1-MHz switching to shrink passive size while maintaining 94% efficiency at 10 mA idle current - directly extending talk time. | Use Scenario: Supplies 1.5 V to MEMS accelerometer, gyroscope, and BLE SoC in compact fitness tracker. IC Role / Device Role / Timing Role: Always-on power source with 0.1 µA shutdown current and automatic PFM wake-up on motion interrupt. Use Value: Delivers 15 µA quiescent current in PFM mode - reduces average system power by 3× vs. LDO solutions, enabling multi-week battery life. |
| Portable Medical Glucose Meter | Industrial Handheld Scanner |
Use Scenario: Provides precision 1.5 V bias to analog front-end (AFE) and microcontroller in Class II medical glucose meter. IC Role / Device Role / Timing Role: Low-noise, tightly regulated supply with ±5% output tolerance and <20 mV ripple under 200 mA pulsed load. Use Value: Internal synchronous rectification and 1-MHz PWM reduce output ripple vs. lower-frequency alternatives - improving ADC SNR by ≥2 dB. | Use Scenario: Powers 1.5 V logic rail for barcode image sensor and FPGA configuration in ruggedized warehouse scanner. IC Role / Device Role / Timing Role: Robust DC-DC converter supporting wide input (2.5–5.5 V) to accommodate aging alkaline or Li-ion packs. Use Value: 100% duty-cycle operation maintains regulation down to 1.65 V input - ensures reliable boot and scan function until battery depletion. |
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 | Fixed 1.5 V output, 300 mA max, 2.05–6.0 V input, 17 µA IQ, 3.5 mm × 3.5 mm DSBGA | Higher input range but lower current rating; smaller package but no 100% duty cycle | Prefer when board space is more constrained than current capability, and input may exceed 5.5 V |
| AP63201WS-7 | Fixed 1.5 V output, 300 mA max, 2.5–5.5 V input, 22 µA IQ, 1.5 mm × 1.5 mm WLCSP | Same input range and output, but higher quiescent current and no LDO mode | Prefer for ultra-miniature wearables where 1.5 mm × 1.5 mm footprint outweighs efficiency and dropout trade-offs |
Compared with TPS62231DRYR and AP63201WS-7, the LM3670MF-1.5 offers superior dropout performance (100% duty cycle), lowest shutdown current (0.1 µA), and proven reliability in high-volume mobile designs - making it optimal for battery-critical, space-constrained applications demanding extended runtime and robust low-VIN operation.
Availability
LM3670MF-1.5 is available at Aetrix Electronics and suitable for mobile phones, wearable sensors, portable medical devices, and industrial handheld scanners requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.
Supply support for LM3670MF-1.5 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, embedded processing, and power management ICs, with leadership in high-efficiency DC-DC conversion for portable electronics.
The LM3670MF-1.5 belongs to TI's miniature step-down DC-DC converter product line, designed specifically to replace linear regulators in ultralow-voltage battery-powered systems where efficiency, size, and light-load performance are critical.
FAQ
What is the recommended inductor value for LM3670MF-1.5?
The LM3670MF-1.5 is optimized for 4.7 µH or 10 µH shielded surface-mount inductors with ≥800 mA saturation current rating and <0.3 Ω DC resistance. A 10 µH inductor (e.g., Coilcraft DO1608C-103) is recommended for best EMI performance and transient response. Using 4.7 µH yields slightly higher ripple but faster load-step recovery - both values are validated in TI's reference designs for LM3670MF-1.5.
Does LM3670MF-1.5 require an external feedback resistor divider?
No. The LM3670MF-1.5 is a fixed-output variant with internally trimmed 1.5 V regulation; the FB pin is not user-accessible and is connected to an internal 0.5 V reference and resistor network. External resistors are only required for the adjustable version (LM3670SD-ADJ). Using LM3670MF-1.5 eliminates feedback component placement error and improves output voltage accuracy stability over temperature.
What is the maximum ambient temperature for continuous operation of LM3670MF-1.5?
The LM3670MF-1.5 supports continuous operation up to +85°C ambient temperature (TA) with proper PCB copper area (≥250 mm² 2-oz copper under package) and airflow. Its junction temperature limit is +125°C, and thermal resistance is RθJA = 163.3°C/W in standard SOT-23 layout. At 350 mA load and 3.6 V input, typical junction rise is ~42°C above ambient - confirming safe operation within industrial temperature range.
How does LM3670MF-1.5 handle input voltage dropout near battery end-of-life?
The LM3670MF-1.5 enters 100% duty-cycle LDO mode when input voltage approaches VOUT, maintaining regulated 1.5 V output down to ~1.65 V input at 100 mA load. This is enabled by its internal PMOS switch operating in triode region, with dropout governed by ILOAD × (RDS(on,P) + RINDUCTOR). Unlike conventional buck converters, LM3670MF-1.5 avoids abrupt shutdown - extending usable battery capacity by up to 12% in single-cell Li-Ion systems.
Can LM3670MF-1.5 be used with ceramic output capacitors only?
Yes. LM3670MF-1.5 is fully compatible with low-ESR ceramic output capacitors - a 10 µF X5R/X7R 0603 or 0805 capacitor is specified in TI's datasheet and reference designs. Ceramic caps provide superior high-frequency ripple suppression and eliminate electrolytic aging concerns. No series ESR is required; adding a small RC snubber (e.g., 1 Ω + 10 nF) across the output cap may further reduce high-frequency switching noise if measured in sensitive RF sections.
LM3670MF-1.5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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):
- 1.5V
- 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-1.5 FAQ
1.How can I place an order for LM3670MF-1.5 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3670MF-1.5 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-1.5 reliable?
The price and inventory of LM3670MF-1.5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3670MF-1.5 is usually 5 days.
3.What payment methods are accepted for LM3670MF-1.5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3670MF-1.5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3670MF-1.5?
LM3670MF-1.5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3670MF-1.5 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-1.5?
For technical support, including LM3670MF-1.5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3670MF-1.5 requirements.
6.How does Aetrix verify that LM3670MF-1.5 is sourced from the original manufacturer or authorized distributors?
All LM3670MF-1.5 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-1.5 meets industry standards.
7.What is the process for return or replacement of LM3670MF-1.5?
All LM3670MF-1.5 units undergo pre-shipment inspection (PSI). If there is an issue with LM3670MF-1.5, 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-1.5 part is unused and in its original packaging.
Return procedure for LM3670MF-1.5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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