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Texas Instruments LM3404MR
- Part No.:
- LM3404MR
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 8-PowerSOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM3404MR.pdf
- Description:
- IC LED DRV RGLTR PWM 8SOPWRPAD
- Quantity:
- Payment:
- Shipping:
Inventory:1,692
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Product details
Overview
LM3404MR from Texas Instruments is a monolithic 1-A constant-current buck regulator IC designed to drive high-power LED arrays in automotive and industrial lighting systems. It integrates a high-side N-channel MOSFET (RDS(on) = 0.75 Ω typ), operates from 6 V to 42 V input, delivers up to 1.2-A output current, features cycle-by-cycle current limiting, and supports PWM dimming via the DIM pin for precise light intensity control.
For engineers reviewing the LM3404MR datasheet, LM3404MR pinout, LM3404MR application, or LM3404MR equivalent, key selection considerations include its hysteretic controlled-on-time (COT) architecture eliminating loop compensation, 200-mV current-sense reference accuracy, thermal shutdown at 165°C, SOIC-8 PowerPAD™ package for enhanced thermal performance, and compatibility with ceramic-only or capacitor-less output configurations.
Technical Context
The LM3404MR implements a controlled-on-time (COT) buck topology with hysteretic feedback, where on-time is set by an external RON resistor and inversely scales with input voltage - enabling stable switching frequency in continuous conduction mode (CCM). Its internal 7-V linear regulator powers gate drive and control circuits from VIN, and the bootstrap circuit (BOOT–SW) sustains high-side MOSFET operation using a 10-nF ceramic capacitor.
Current regulation is achieved via a precision 200-mV CS pin reference with ±6 mV tolerance over temperature, while overvoltage protection triggers at 300 mV on the same pin. The device enforces a 300-ns minimum off-time, limiting maximum duty cycle and defining VO(MAX) per input voltage and switching frequency - critical for open-LED fault handling and series-string LED count planning.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 6 V to 42 V - supports 12 V/24 V automotive and industrial bus rails without external pre-regulation |
| Output Current | 1.2 A max - sufficient for driving single high-power LEDs or multi-LED strings up to ~35 W at 24 V |
| CS Reference Voltage | 200 mV ±6 mV - sets LED current via RSNS = 0.2 V / IF; enables <±1% current accuracy with 1% sense resistor |
| RDS(on) | 0.75 Ω typ - limits conduction loss to <1.1 W at 1.2 A, reducing thermal load in SOIC-8 PowerPAD package |
| Thermal Shutdown | 165°C with 25°C hysteresis - protects die during overload or poor heatsinking; auto-recovery after cooldown |
| Switching Frequency Range | ~100 kHz to >1 MHz - programmable via RON; higher frequencies shrink inductor size but trade efficiency |
| PWM Dimming Input | DIM pin TTL-compatible (VIL ≤0.8 V, VIH ≥2.2 V) - enables flicker-free dimming down to 100 Hz without requiring external logic |
Pinout & Package
LM3404MR is packaged in an 8-pin SOIC with exposed PowerPAD™ (DDA package), measuring 3.90 mm × 4.89 mm. The PowerPAD must be soldered to a PCB ground plane using 4–6 thermal vias for optimal thermal dissipation (RθJB = 24.5°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW | Switch node | Connects to inductor and Schottky diode cathode; carries high di/dt switching current - requires tight layout and low-inductance routing |
| BOOT | Bootstrap supply | Drives high-side MOSFET gate; requires 10-nF ceramic capacitor to SW to sustain gate voltage above VIN during on-state |
| DIM | PWM dimming input | TTL-level control: logic low disables LED current instantly; internal 75-µA pullup ensures default-on if left floating |
| GND | Power and signal ground | Common return for CS, RON, DIM, and VCC bypass; must be low-impedance and tied to PowerPAD |
| CS | Current sense feedback | Compares VSNS against 200-mV reference; connects to RSNS resistor to ground - determines LED current magnitude |
| RON | On-time programming | Resistor from RON to VIN sets tON; defines switching frequency and maximum output voltage capability |
| VCC | Internal bias supply | 7-V regulated output; must be bypassed with ≥0.1-µF X5R/X7R ceramic capacitor close to pin for stable gate drive |
| VIN | Main power input | Supplies both power stage and internal regulator; accepts 6–42 V DC - includes undervoltage lockout at 5.3 V |
Key Features
| Feature | Design Value |
|---|---|
| No control loop compensation required | Hysteretic COT architecture eliminates external compensation network - reduces BOM count and design iteration time |
| Supports capacitor-less outputs | Direct inductor-to-LED connection enabled by CCM operation and valley-current regulation - cuts cost and footprint in space-constrained lighting modules |
| Integrated 1-A MOSFET with 0.75 Ω RDS(on) | Eliminates external switch and associated gate driver; simplifies layout and improves reliability versus discrete solutions |
| Separate PWM dimming and shutdown | DIM pin controls light intensity; RON pin enables full system-level power-down with <180 µA quiescent current - ideal for standby modes |
| Built-in open-LED protection | OVP comparator triggers at 300 mV on CS pin - prevents runaway output voltage during LED string breakage, avoiding component overstress |
Applications
| Automotive Headlamp Driver | Industrial Machine Vision Lighting |
|---|---|
Use Scenario: Driving high-brightness white LED arrays in adaptive front-lighting systems (AFS) with dynamic beam shaping. IC Role / Device Role / Timing Role: Constant-current buck controller regulating 700 mA–1.2 A through 4–8 series-connected LEDs; provides fast PWM dimming response (<1 µs MOSFET turn-off) for real-time beam modulation. Use Value: Enables compliance with ECE R149 photometric requirements via precise current stability (±1.5% over temp) and thermal foldback at 165°C. | Use Scenario: Illuminating high-speed inspection zones in factory automation, requiring strobed, uniform LED illumination synchronized to camera exposure. IC Role / Device Role / Timing Role: High-efficiency current source delivering 1 A at 36 V output; DIM pin accepts 1–10 kHz external PWM for sub-millisecond flash timing control. Use Value: Eliminates need for external current-sense amplifiers or microcontroller-based dimming logic - reduces system latency and component count. |
| Commercial Streetlight LED Module | Architectural Accent Lighting |
Use Scenario: Outdoor LED luminaires operating from 24 V or 48 V DC microgrids, subject to wide ambient temperature swings (−40°C to +85°C). IC Role / Device Role / Timing Role: Primary current regulator in multi-string configuration; uses RON resistor to fix switching frequency at 350 kHz for EMI compliance and inductor size optimization. Use Value: Maintains ±3% LED current accuracy across full temperature range due to 200-mV reference drift <±10 ppm/°C - ensures consistent lumen output over lifetime. | Use Scenario: Low-profile indoor linear LED strips for cove and wall-wash lighting, where thermal management is constrained by aluminum extrusion geometry. IC Role / Device Role / Timing Role: Compact constant-current driver in SOIC-8 PowerPAD package; dissipates heat directly into metal housing via thermal vias under DAP. Use Value: Achieves 44.7°C/W junction-to-ambient thermal resistance - allows 1.2 A operation at 75°C ambient without derating when mounted to ≥10 cm² copper area. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar constant-current LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3404MH/NOPB | Same silicon, SOIC-8 (non-PowerPAD) package; RθJA = 106.8°C/W vs. 44.7°C/W - 2.4× higher thermal resistance | Suitable only for lower-current (≤600 mA) or forced-air-cooled designs; not recommended for sealed outdoor enclosures | Select LM3404MR when thermal performance is critical; choose LM3404MH only if board space prohibits PowerPAD layout or cost sensitivity outweighs thermal margin |
| MPQ4425HGJ-P | Monolithic 1.2-A buck LED driver with integrated 0.25-Ω MOSFET; 4.5–40 V input; requires external compensation; no dedicated DIM pin - dimming via analog or PWM on EN | Offers higher efficiency at 1 A (94% vs. 91%) but lacks pin-compatible dimming interface and open-LED protection threshold | Choose MPQ4425HGJ-P for efficiency-critical battery-powered systems; retain LM3404MR when seamless PWM integration, thermal robustness, or fail-safe OVP are mandatory |
Compared with LM3404MH/NOPB, LM3404MR delivers superior thermal performance essential for high-reliability LED lighting, while MPQ4425HGJ-P offers higher efficiency but requires redesign of dimming and fault-protection circuitry - making LM3404MR the optimal choice for thermally demanding, drop-in-replaceable automotive and industrial LED drivers.
Availability
LM3404MR is available at Aetrix Electronics and suitable for automotive headlamps, industrial machine vision lighting, and commercial streetlight LED modules requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for LM3404MR 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, specializing in analog, embedded processing, and digital signal processing technologies for industrial, automotive, and consumer markets.
The LM3404MR belongs to TI's high-reliability LED driver product line, engineered specifically for constant-current regulation in harsh-environment lighting applications - emphasizing thermal resilience, fault protection, and simplified system integration.
FAQ
What is the maximum LED string voltage supported by the LM3404MR?
The LM3404MR's maximum output voltage (VO(MAX)) depends on input voltage and switching frequency, governed by its 300-ns minimum off-time. At VIN = 42 V and fSW = 250 kHz, VO(MAX) ≈ 38 V. This supports up to 10 white LEDs (VF ≈ 3.2 V each) in series. For higher strings, reduce fSW or use the LM3404HV variant (75 V VIN).
Does the LM3404MR require an output capacitor for stable operation?
No - the LM3404MR supports capacitor-less operation due to its controlled-on-time architecture and continuous conduction mode. The inductor directly regulates LED current; adding an output capacitor only reduces ripple. A 10-nF ceramic cap across the LED array is recommended to dampen ringing during open-circuit faults.
How does the LM3404MR handle open-LED conditions?
During an open-LED fault, the CS pin voltage falls to 0 V, commanding maximum duty cycle. The LM3404MR's OVP comparator disables the MOSFET when CS exceeds 300 mV - preventing uncontrolled VO rise. Combined with the 300-ns minimum off-time limit, this caps VO(MAX) below VIN and avoids damage to external components.
What is the purpose of the RON pin on the LM3404MR?
The RON pin sets the controlled on-time (tON) via an external resistor to VIN. tON determines switching frequency and maximum achievable output voltage. For example, RON = 200 kΩ yields tON ≈ 2.75 µs at VIN = 10 V, fixing fSW ≈ 350 kHz - enabling predictable EMI filtering and inductor selection.
Can the LM3404MR be used with 12-V automotive battery input?
Yes - the LM3404MR's 6–42 V input range fully covers nominal 12-V automotive systems, including cold-crank (down to 6 V) and load-dump transients (up to 42 V). Its internal 7-V VCC regulator remains functional across this range, and thermal shutdown (165°C) ensures reliability under hood temperatures.
LM3404MR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-PowerSOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- Type:
- DC DC Regulator
- Topology:
- Step-Down (Buck)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 6V
- Voltage - Supply (Max):
- 42V
- Voltage - Output:
- 40V
- Current - Output / Channel:
- 1A
- Frequency:
- 1MHz
- Dimming:
- PWM
- Applications:
- Lighting
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- Automotive
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SO PowerPad
LM3404MR FAQ
1.How can I place an order for LM3404MR through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3404MR 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 LM3404MR reliable?
The price and inventory of LM3404MR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3404MR is usually 5 days.
3.What payment methods are accepted for LM3404MR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3404MR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3404MR?
LM3404MR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3404MR 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 LM3404MR?
For technical support, including LM3404MR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3404MR requirements.
6.How does Aetrix verify that LM3404MR is sourced from the original manufacturer or authorized distributors?
All LM3404MR 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 LM3404MR meets industry standards.
7.What is the process for return or replacement of LM3404MR?
All LM3404MR units undergo pre-shipment inspection (PSI). If there is an issue with LM3404MR, 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 LM3404MR part is unused and in its original packaging.
Return procedure for LM3404MR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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