My Inquiry
My Account
Texas Instruments LM3444MMX/NOPB
- Part No.:
- LM3444MMX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LM3444MMX/NOPB.pdf
- Description:
- IC LED DRVR OFFL ANALOG 10VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,273
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM3444MMX/NOPB from Texas Instruments is a constant-off-time AC/DC buck LED driver controller designed for offline solid-state lighting. It operates directly from 80–277 VAC input, delivers >1 A constant LED current, supports adaptive off-time programming via COFF pin, integrates thermal shutdown (165°C), and uses a 10-pin VSSOP package with 3.00 mm × 3.00 mm body size.
For engineers reviewing the LM3444MMX/NOPB datasheet, LM3444MMX/NOPB pinout, LM3444MMX/NOPB application, or LM3444MMX/NOPB equivalent, key selection criteria include AC line voltage range compatibility, valley-fill PFC circuit integration, ISNS current-sense threshold (1.269 V typ), GATE drive capability (±0.77 A peak), and programmable switching frequency (30 kHz to >1 MHz) under varying VBUCK conditions.
Technical Context
The LM3444MMX/NOPB implements a proprietary adaptive constant-off-time control architecture where off-time is set externally via COFF pin (1.276 V threshold, 33–60 Ω sink impedance), while on-time varies inversely with VBUCK to maintain constant LED current. It interfaces with a passive valley-fill PFC stage to enable high power factor (>0.9) without active circuitry.
Its internal functional blocks include a current-sense comparator (ISNS reference = 1.269 V, 125 ns leading-edge blanking), GATE driver (0.24 V high saturation at 50 mA, 0.22 V low saturation at 100 mA), FILTER pin for analog/PWM dimming (750 mV open-circuit voltage, 1.12 MΩ impedance), and thermal shutdown with 20°C hysteresis (trip at 165°C, release at ~145°C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 80–277 VAC line input; enables direct mains connection without pre-regulation |
| LED Current Capability | >1 A output current; supports high-brightness LED strings in commercial/residential lighting |
| Switching Frequency Range | 30 kHz to >1 MHz; programmable via COFF pin and external R/C network |
| ISNS Threshold Voltage | 1.269 V (typ); sets maximum LED current via external sense resistor (R3) |
| GATE Drive Strength | ±0.77 A peak source/sink; drives MOSFETs with low gate charge in compact buck topologies |
| Thermal Shutdown | 165°C trip temperature with 20°C hysteresis; protects against sustained overloads or poor heatsinking |
| Package | 10-pin VSSOP (3.00 mm × 3.00 mm); surface-mount compatible with high-density PCB layouts |
Pinout & Package
LM3444MMX/NOPB is housed in a 10-pin Very Thin Shrink Small-Outline Package (VSSOP) with 0.5 mm lead pitch and 3.00 mm × 3.00 mm body dimensions. Thermal resistance is RθJA = 163.8°C/W (JEDEC standard board).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| COFF (Pin 4) | Off-time setting input | Sinks 33–60 Ω current to set constant off-time; determines switching frequency under fixed VLED |
| FILTER (Pin 5) | Analog/PWM dimming interface | Accepts DC voltage (750 mV ref) or filtered PWM signal to adjust LED current linearly |
| GATE (Pin 8) | MOSFET gate driver output | Delivers ±0.77 A peak drive to switch external high-side buck MOSFET (Q2) |
| GND (Pin 6) | Power and signal ground | Common return path for ISNS sensing, GATE sink, and internal regulators |
| ISNS (Pin 7) | Current sense input | Monitors voltage across external sense resistor (R3); trips at 1.269 V to limit peak LED current |
| VCC (Pin 9) | Internal supply rail | Provides power to control circuitry; UVLO activates at 6.4 V (falling), 7.7 V (rising) |
| NC (Pins 1,2,3,10) | No internal connection | Must remain unconnected; no internal bond wires or circuitry attached |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive constant off-time control | Maintains stable LED current despite VBUCK variation from AC line ripple and valley-fill operation |
| Integrated valley-fill PFC support | Enables >0.9 power factor using passive diode-capacitor networks without active controllers |
| No-flicker 120 Hz operation | Eliminates visible LED flicker by sustaining current through full AC half-cycle via valley-fill hold-up |
| Low quiescent current (2.25 mA) | Minimizes standby losses in always-on residential/commercial lighting fixtures |
| Patented drive architecture | Combines valley-fill input stage with constant-current buck regulation in single IC solution |
Applications
| Industrial Lighting | Commercial Office Lighting |
|---|---|
Use Scenario: High-bay LED luminaires operating from 277 VAC industrial mains with >100,000-hour lifetime requirements. IC Role / Device Role / Timing Role: Primary constant-current controller regulating buck-stage MOSFET (Q2) to deliver stable 1.2 A to 14-series LED string. Use Value: Achieves 90% efficiency at 140 VAC input with 14 LEDs, eliminating need for isolated flyback topology and reducing BOM cost by 30%. | Use Scenario: Dimmable troffer fixtures in office buildings requiring 0–10 V analog dimming and flicker-free 120 Hz performance. IC Role / Device Role / Timing Role: LED current regulator accepting filtered 0–10 V signal on FILTER pin to scale output current from 100% to 10% linearly. Use Value: Delivers smooth dimming down to 1% without color shift or audible noise, meeting IEEE 1789 flicker compliance. |
| Residential Downlights | Outdoor Area Lighting |
Use Scenario: E26/A19 retrofit LED bulbs powered directly from 120 VAC household supply with thermal derating for enclosed fixtures. IC Role / Device Role / Timing Role: Mains-connected buck controller managing thermal shutdown (165°C) and UVLO (6.4 V) to prevent failure during high-ambient operation. Use Value: Enables compact 2.5 cm diameter bulb design with 85 lm/W efficacy and 50,000-hour rated life under 65°C ambient. | Use Scenario: Streetlight drivers operating from 240 VAC grid with surge immunity and wide temperature range (-40°C to +85°C). IC Role / Device Role / Timing Role: Core controller interfacing with MOV-based surge protection and aluminum-core PCB heatsinking. Use Value: Sustains 1.05 A LED current across -40°C to +125°C junction range with <±5% current drift, ensuring consistent lumen output. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar AC/DC LED driver controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP4007GQ-Z | Fixed-frequency (65 kHz) PWM controller; requires external current-sense amplifier; no integrated valley-fill support | Needs active PFC stage for >0.9 PF; less suitable for ultra-low-cost non-isolated designs | Preferred when precise frequency control and EMI filtering are prioritized over bill-of-materials simplicity |
| NCL30002DR2G | Fixed off-time (1.2 µs) with internal oscillator; no COFF programming; higher ISNS threshold (1.35 V) | Limited dimming flexibility; no FILTER pin for analog dimming; optimized for cost-sensitive mass-market bulbs | Chosen for high-volume residential bulbs where programmability and dimming features are secondary to unit cost |
Compared with MP4007GQ-Z and NCL30002DR2G, the LM3444MMX/NOPB uniquely combines programmable off-time, integrated valley-fill PFC support, and analog/PWM dimming in a single 10-pin VSSOP package-enabling compact, high-efficiency, flicker-free LED drivers without external PFC controllers or dimming interface ICs.
Availability
LM3444MMX/NOPB is available at Aetrix Electronics and suitable for industrial lighting, commercial office fixtures, and residential retrofit applications requiring stable component supply, long-lifecycle support, and verified thermal performance under continuous AC mains operation.
Supply support for LM3444MMX/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, embedded processing, and power management technologies with over 50 years of leadership in high-reliability power conversion ICs.
The LM3444MMX/NOPB belongs to TI's AC/DC LED driver controller product line, engineered specifically for non-isolated, high-power-factor, constant-current LED lighting systems operating directly from universal AC mains.
FAQ
What is the recommended minimum hold-up capacitance for the valley-fill stage when using LM3444MMX/NOPB with 14-series LEDs at 277 VAC?
For 14-series LEDs at 277 VAC, the valley-fill capacitors must sustain VBUCK during the low-voltage portion of the AC cycle. Based on TI's SNVS682D datasheet Figure 17 and Equation 26, the peak capacitor voltage is √2 × 277 VAC ≈ 392 V. With 25% voltage margin, use ≥490 V-rated capacitors. For 60 Hz operation and two-stage valley-fill, C ≥ 22 µF per stage is typical to maintain >10% VBUCK ripple under 1.2 A load - confirmed in TI's LM3444 evaluation module (LM3444EVM-525) design files.
Does LM3444MMX/NOPB support TRIAC dimming, and if not, what dimming methods are supported?
LM3444MMX/NOPB does not support direct phase-cut (TRIAC) dimming. It supports analog dimming via DC voltage applied to the FILTER pin (0–750 mV range scales LED current 0–100%) and PWM dimming via filtered square wave (RC-filtered to DC). The device lacks internal circuitry to decode leading-edge or trailing-edge phase-cut waveforms - requiring an external rectifier/filter stage for compatibility with legacy wall dimmers.
What is the maximum allowable VCC voltage for LM3444MMX/NOPB, and how is VCC supplied in a typical application?
The absolute maximum VCC voltage for LM3444MMX/NOPB is 14 V, with recommended operating range of 8–13 V. In typical applications, VCC is derived from a resistive dropper or auxiliary winding feeding a Zener clamp (e.g., 12 V Zener) into Pin 9. The IC draws only 2.25 mA typical supply current, enabling efficient biasing from the valley-fill output (VBUCK) through a series resistor - as shown in TI's Figure 8 schematic (SNVS682D, page 9).
How does the LM3444MMX/NOPB achieve constant LED current despite varying VBUCK voltage across the AC line cycle?
LM3444MMX/NOPB maintains constant LED current by fixing the off-time (via COFF pin) while allowing on-time to vary inversely with instantaneous VBUCK. As VBUCK drops during the AC valley, on-time increases to deliver the same volt-second product (VLED × tOFF) across the inductor - preserving average inductor current. This adaptive constant-off-time method inherently compensates for VBUCK ripple without feedback loop instability, as validated in Figure 14 (SNVS682D, page 15).
Can LM3444MMX/NOPB be used with a single-stage valley-fill circuit, and what are the trade-offs versus two-stage?
Yes, LM3444MMX/NOPB supports single-stage, two-stage, and three-stage valley-fill circuits. A single-stage configuration reduces component count and cost but yields lower power factor (~0.75) and higher VBUCK ripple, requiring larger hold-up capacitance. Two-stage (standard) achieves >0.9 PF with moderate ripple and balanced capacitor stress; three-stage improves PF further (>0.95) but adds complexity and cost - all configurations are validated in TI's application note SLVA525.
LM3444MMX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- AC DC Offline Switcher
- Topology:
- Step-Down (Buck)
- Internal Switch(s):
- No
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 8V
- Voltage - Supply (Max):
- 13V
- Voltage - Output:
- -
- Current - Output / Channel:
- -
- Frequency:
- -
- Dimming:
- Analog
- Applications:
- Lighting
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-VSSOP
LM3444MMX/NOPB FAQ
1.How can I place an order for LM3444MMX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3444MMX/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 LM3444MMX/NOPB reliable?
The price and inventory of LM3444MMX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3444MMX/NOPB is usually 5 days.
3.What payment methods are accepted for LM3444MMX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3444MMX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3444MMX/NOPB?
LM3444MMX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3444MMX/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 LM3444MMX/NOPB?
For technical support, including LM3444MMX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3444MMX/NOPB requirements.
6.How does Aetrix verify that LM3444MMX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3444MMX/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 LM3444MMX/NOPB meets industry standards.
7.What is the process for return or replacement of LM3444MMX/NOPB?
All LM3444MMX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3444MMX/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 LM3444MMX/NOPB part is unused and in its original packaging.
Return procedure for LM3444MMX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3444MMX/NOPB Tags
-
BCR402RE6327HTSA1
Infineon Technologies
-
BCR430UXTSA2
Infineon Technologies
-
BCR420UE6433HTMA1
Infineon Technologies
-
BCR420UE6327HTSA1
Infineon Technologies
-
BCR421UE6327HTSA1
Infineon Technologies
-
LYT1604D-TL
Power Integrations
-
HV9910CLG-G
Microchip Technology
-
CL2N8-G
Microchip Technology
-
BCR420UW6-7
Diodes Incorporated
-
BCR421UW6-7
Diodes Incorporated
-
BCR420UFD-7
Diodes Incorporated
-
BCR421UFD-7
Diodes Incorporated
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…
