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Texas Instruments LM3497MMX/NOPB
- Part No.:
- LM3497MMX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LM3497MMX/NOPB.pdf
- Description:
- IC LED DRIVER OFFL TRIAC 10VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,734
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Product details
Overview
LM3497MMX/NOPB from Texas Instruments (formerly National Semiconductor) is a triac-dimmable offline AC/DC buck constant-current LED driver controller with integrated triac dim decoder, bleeder circuit, and adaptive constant off-time control. It operates from 80–277VAC input, delivers >1A LED current, supports 30kHz–1MHz switching, and eliminates 120Hz flicker in residential and commercial lighting retrofits.
For engineers reviewing the LM3497MMX/NOPB datasheet, LM3497MMX/NOPB pinout, LM3497MMX/NOPB application, or LM3497MMX/NOPB equivalent, key selection criteria include triac compatibility across 50/60Hz lines, programmable off-time for ripple control, thermal shutdown at 165°C, MSOP-10 package footprint, and dual-function DIM pin for master/slave synchronization.
Technical Context
The LM3497MMX/NOPB implements adaptive constant off-time control to maintain stable LED current despite VBUCK variation across AC half-cycles. Its internal 5.85kHz ramp generator compares against a filtered ASNS signal (0–4V DC) derived from triac conduction angle detection on the BLDR pin.
Angle detection uses a 7.21V threshold comparator on BLDR to drive both the ASNS PWM output and a 230Ω switched bleeder resistor-ensuring triac holding current during low-line periods. The FLTR2 pin provides a 750mV reference voltage with 420kΩ impedance for current-sense comparator biasing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 80–277VAC line-compatible; enables global mains operation without external transformer. |
| LED Output Current | >1A continuous; supports high-power single-string or multi-LED arrays in retrofit lamps. |
| Switching Frequency | 30kHz–1MHz programmable via COFF pin; balances EMI, efficiency, and passive size. |
| Dimming Interface | Triac phase-cut decoding with 45°–135° conduction angle range; no 120Hz flicker. |
| Thermal Protection | 165°C junction shutdown with 20°C hysteresis; prevents damage under sustained overload. |
| Package | MSOP-10 (MUB10A); 3mm × 3mm footprint with exposed thermal pad for compact LED driver PCBs. |
| VCC Operating Range | 8.0–12V; powers internal logic and gate driver; UVLO rising/falling thresholds at 7.7V/6.4V. |
Pinout & Package
LM3497MMX/NOPB is housed in a thermally enhanced 10-pin MSOP package (NS Package Number MUB10A), featuring an exposed thermal pad for improved power dissipation in high-current LED driver applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ASNS | Triac dim decoder PWM output | 0–4V duty-cycle-proportional signal reflecting triac on-time; feeds FLTR1 for dimming control. |
| FLTR1 | Dim decoder ramp comparator input | Accepts filtered ASNS; tied above 4.9V disables dim decoder for master/slave configuration. |
| DIM | Dual-function dim control | Accepts external PWM or outputs synchronized dim signal to other LM3497 devices. |
| COFF | Constant off-time setting | Sets tOFF via external R-C network; determines switching frequency and ripple stability. |
| FLTR2 | Current reference filter | 750mV open-circuit voltage reference with 420kΩ impedance; sets peak LED current threshold. |
| GND | Power and signal ground | Common return for ISNS, GATE, VCC, and internal comparators; requires low-impedance layout. |
| ISNS | Current sense input | Monitors MOSFET source voltage; triggers GATE turn-off when sensed voltage reaches 1.269V. |
| GATE | MOSFET driver output | Drives external N-channel switch; 0.5V saturation drop at 50mA sink/source; 0.77A peak sink. |
| VCC | Bias supply input | 8–12V internal supply; powers control logic and gate driver; includes 7.7V UVLO with hysteresis. |
| BLDR | Triac angle sensing input | Monitors rectified line via external regulator; 7.21V comparator threshold enables firing-angle detection. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated triac dim decoder | Converts phase-cut waveform into stable 0–4V DC dim signal-enabling seamless compatibility with legacy wall dimmers. |
| Programmable constant off-time | Enables fixed ripple current across wide VBUCK range (e.g., 20–40V), simplifying inductor selection and improving regulation. |
| Active bleeder circuit | Switches 230Ω load only when BLDR <7.21V-ensures triac holding current without sacrificing efficiency at full brightness. |
| No 120Hz flicker architecture | Valley-fill PFC stage + high-frequency buck control eliminates perceptible flicker-meets IEEE 1789 Class A requirements. |
| Master/slave DIM synchronization | Single DIM pin drives multiple LM3497 units; FLTR1 tri-state enables centralized dimming control for multi-fixture systems. |
Applications
| Retrofit Triac Dimming | Solid State Lighting |
|---|---|
|
Use Scenario: Replacing incandescent bulbs in existing residential wall dimmer circuits with LED-based A19 or PAR30 lamps. IC Role / Device Role / Timing Role: Offline buck controller with triac angle decoding and bleeder current management-replaces legacy magnetic transformers. Use Value: Enables direct drop-in replacement without rewiring; maintains smooth 0–100% dimming while eliminating audible buzz and flicker. |
Use Scenario: High-efficiency LED luminaires for office ceiling troffers and downlights operating from 120/277VAC mains. IC Role / Device Role / Timing Role: Constant-current buck controller with passive PFC and adaptive off-time-regulates LED string current across line variations. Use Value: Achieves >85% efficiency and >0.9 PF without active PFC IC; supports >1A output with minimal heatsink requirement. |
| Industrial Lighting | Commercial Retrofit |
|
Use Scenario: High-bay LED fixtures in warehouses using 277VAC industrial distribution with standard triac dimming panels. IC Role / Device Role / Timing Role: Mains-connected LED driver with thermal shutdown and robust overvoltage protection-handles brownouts and surges. Use Value: Sustains operation at −40°C to +125°C junction temperature; 165°C thermal cutoff prevents field failures in enclosed fixtures. |
Use Scenario: Hotel corridor and lobby lighting upgrades requiring smooth dimming, low EMI, and UL Class P compliance. IC Role / Device Role / Timing Role: Triac-dimmable controller with valley-fill PFC and high-frequency switching-reduces EMI filter size and cost. Use Value: Meets FCC Class B conducted emissions with minimal external filtering; supports compact, low-profile lamp designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar triac-dimmable LED driver controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor NCL30000DR2G | Fixed 500kHz frequency; no programmable off-time; requires external bleeder resistor. | Limited dimming range (10–100%) vs LM3497MMX/NOPB's 0–100%; no master/slave DIM sync. | Preferred for cost-sensitive, fixed-frequency designs where full dim range is not required. |
| Diodes Incorporated AL1676S16-13 | Integrated 600V MOSFET; no external switch needed; lower max output current (700mA). | Eliminates external FET but limits power scalability; lacks ASNS/FLTR1 flexibility for custom dim decoding. | Best for ultra-compact, low-to-mid power (<20W) drivers where board space is critical. |
Compared with NCL30000DR2G and AL1676S16-13, LM3497MMX/NOPB offers wider dimming range, programmable off-time for ripple optimization, and native master/slave capability-making it optimal for high-power, multi-fixture, and design-flexible LED driver platforms.
Availability
LM3497MMX/NOPB is available at Aetrix Electronics and suitable for residential lighting retrofits, commercial solid-state luminaires, and industrial high-bay LED drivers requiring stable component supply and long-term manufacturability.
Supply support for LM3497MMX/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 acquired National Semiconductor in 2011 and maintains its analog power portfolio, including high-reliability LED driver ICs designed for energy-efficient lighting systems.
The LM3497 product line was developed specifically for triac-dimmable offline LED drivers-targeting retrofit compatibility, flicker-free operation, and simplified passive PFC integration in AC-powered lighting.
FAQ
What is the primary function of the LM3497MMX/NOPB in an LED lighting system?
The LM3497MMX/NOPB serves as a triac-dimmable offline AC/DC buck constant-current controller. It decodes phase-cut dimmer signals, regulates LED current via adaptive constant off-time control, and integrates a bleeder circuit to ensure reliable triac firing-enabling flicker-free dimming from 80–277VAC inputs without external microcontrollers.
How does the LM3497MMX/NOPB eliminate 120Hz flicker in LED lighting?
The LM3497MMX/NOPB eliminates 120Hz flicker by combining a valley-fill passive PFC circuit-which extends conduction time across the AC half-cycle-with high-frequency buck switching (30kHz–1MHz). This architecture avoids low-frequency current modulation, meeting IEEE 1789 Class A flicker requirements without additional post-regulation stages.
Can the LM3497MMX/NOPB support multiple LED strings controlled by one triac dimmer?
Yes, the LM3497MMX/NOPB supports master/slave configurations via its DIM pin. One LM3497MMX/NOPB configured as master (with FLTR1 tied to VCC) can drive multiple slave units by connecting their DIM pins together-enabling synchronized dimming across independent LED driver circuits without signal degradation or timing skew.
What is the role of the BLDR pin on the LM3497MMX/NOPB?
The BLDR pin on the LM3497MMX/NOPB senses the rectified AC line voltage through an external series pass regulator. It feeds the internal angle-detect comparator (7.21V threshold) to determine triac conduction state and activates the 230Ω switched bleeder resistor when voltage falls below threshold-ensuring sufficient holding current for proper triac operation across all dim levels.
Does the LM3497MMX/NOPB require an external MOSFET, and what are its gate drive specifications?
Yes, the LM3497MMX/NOPB requires an external N-channel MOSFET. Its GATE pin delivers up to 0.77A peak sink and 0.88A peak source current, with 0.5V saturation drop at 50mA sink. Rise/fall times are 15ns into 1nF load-supporting fast-switching FETs for high-efficiency, low-EMI buck operation up to 1MHz.
LM3497MMX/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):
- 12V
- Voltage - Output:
- -
- Current - Output / Channel:
- -
- Frequency:
- -
- Dimming:
- Triac
- Applications:
- Lighting
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-VSSOP
LM3497MMX/NOPB FAQ
1.How can I place an order for LM3497MMX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3497MMX/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 LM3497MMX/NOPB reliable?
The price and inventory of LM3497MMX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3497MMX/NOPB is usually 5 days.
3.What payment methods are accepted for LM3497MMX/NOPB?
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4.How is shipping managed for LM3497MMX/NOPB?
LM3497MMX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3497MMX/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 LM3497MMX/NOPB?
For technical support, including LM3497MMX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3497MMX/NOPB requirements.
6.How does Aetrix verify that LM3497MMX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3497MMX/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 LM3497MMX/NOPB meets industry standards.
7.What is the process for return or replacement of LM3497MMX/NOPB?
All LM3497MMX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3497MMX/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 LM3497MMX/NOPB part is unused and in its original packaging.
Return procedure for LM3497MMX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3497MMX/NOPB Tags
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BCR402RE6327HTSA1
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BCR430UXTSA2
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BCR420UE6433HTMA1
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BCR420UE6327HTSA1
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BCR421UE6327HTSA1
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LYT1604D-TL
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HV9910CLG-G
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CL2N8-G
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BCR420UW6-7
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BCR421UW6-7
Diodes Incorporated
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BCR420UFD-7
Diodes Incorporated
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BCR421UFD-7
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