My Inquiry
My Account
Texas Instruments LM3549SQE/NOPB
- Part No.:
- LM3549SQE/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM3549SQE/NOPB.pdf
- Description:
- IC LED DRV RGLTR I2C 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,431
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM3549SQE/NOPB from Texas Instruments is a high-power sequential RGB LED driver IC with integrated buck-boost DC-DC converter, three 700 mA low-side constant-current drivers, I²C interface, non-volatile memory for standalone operation, and fault detection (LED open/short, thermal, UVLO, OCP). It targets portable video projector light engines requiring precise color sequencing and high-efficiency power conversion.
For engineers reviewing the LM3549SQE/NOPB datasheet, LM3549SQE/NOPB pinout, LM3549SQE/NOPB application, or LM3549SQE/NOPB equivalent, key selection considerations include its 24-pin WQFN package, sequential enable logic (R_EN/G_EN/B_EN priority order), ±6% current accuracy over temperature, 95% peak converter efficiency, and EEPROM-programmable current settings for white balance calibration without continuous I²C control.
Technical Context
The LM3549SQE/NOPB implements a time-multiplexed sequential drive architecture: only one of R_OUT, G_OUT, or B_OUT is active at any time, controlled by dedicated enable inputs with fixed priority (R > G > B). Its integrated buck-boost SMPS dynamically adjusts VOUT to match the forward voltage of the enabled LED, minimizing driver power dissipation.
It combines analog current regulation with digital control-current levels are set via 10-bit registers (stored in EEPROM), brightness is adjusted globally via PWM input or master fader register, and fault conditions (open/short LED, thermal shutdown, UVLO, OCP) trigger an active-low open-drain FAULT signal and flag bits readable over I²C at address 0x36.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Max Output Current | 700 mA per channel - supports high-brightness RGB LEDs in portable projectors |
| Current Accuracy | ±6% over −30°C to +125°C - ensures stable white point across operating temperature range |
| Converter Efficiency | 95% peak - minimizes thermal load and extends battery life in portable systems |
| Input Voltage Range | 2.7 V to 5.5 V - compatible with single-cell Li-ion (3.0–4.2 V) and USB-powered designs |
| Switching Frequency | 2.25–2.55 MHz - enables use of small 2.2 µH inductors and compact ceramic capacitors |
| I²C Address | 0x36 (7-bit) - standard address avoids bus conflicts in multi-device systems |
| Package | 24-pin WQFN (RTW0024A, 4 mm × 4 mm, 0.5 mm pitch) - thermally enhanced for high-power LED driving |
Pinout & Package
LM3549SQE/NOPB uses a 24-pin WQFN package (package code RTW0024A) with exposed thermal pad. Pin 1 identifier is marked on top view; bottom view shows pin numbering clockwise from Pin 1. The package supports high thermal conductivity via soldered thermal pad to PCB ground plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| L1 (Pins 2,3) | Inductor positive terminal | Connects to boost/buck inductor; dual pins reduce parasitic inductance and improve current sharing |
| L2 (Pins 5,6) | Inductor negative terminal | Completes SMPS inductor loop; dual pins enhance thermal and electrical performance |
| VOUT (Pins 7,9) | Buck-boost output | Supplies dynamically adjusted voltage to LED anodes; dual pins lower impedance path |
| R_EN/G_EN/B_EN (Pins 10,12,13) | Sequential enable inputs | Digital control signals with fixed priority (R > G > B); only one active at a time |
| R_OUT/G_OUT/B_OUT (Pins 16–18) | Low-side constant-current outputs | Drive RGB LED cathodes; each delivers up to 700 mA with ±6% accuracy |
| FAULT (Pin 19) | Fault interrupt output | Active-low open-drain signal indicating LED open/short, TSD, UVLO, or OCP |
| SDA/SCL (Pins 20,21) | I²C interface | Standard bidirectional data/clock; requires external pull-ups; address 0x36 |
| EN (Pin 22) | Global enable | Active-high input controlling full device power state (shutdown/standby/normal) |
Key Features
| Feature | Design Value |
|---|---|
| Integrated buck-boost SMPS | Eliminates need for external DC-DC; dynamically tracks LED VF to maximize efficiency and minimize heat in drivers |
| Non-volatile memory (EEPROM) | Stores calibrated current settings for all three banks, enabling fully standalone operation without I²C bus |
| Sequential drive logic with priority | Hardware-enforced R→G→B enable order prevents simultaneous conduction, ensuring safe timing in color-sequential projectors |
| Comprehensive fault detection | Detects and flags LED open/short, thermal shutdown, UVLO, and converter overcurrent - critical for field-reliable projector light engines |
| Global brightness control | Supports both PWM input (4–20 kHz) and I²C master fader register for system-level luminance adjustment while preserving RGB ratios |
Applications
| Portable Video Projectors | RGB Laser/LED Light Engines |
|---|---|
Use Scenario: Compact DLP or LCoS projector modules requiring rapid, precise RGB color sequencing per frame. IC Role / Device Role / Timing Role: Sequential LED driver with dynamic VOUT adjustment and hardware-enforced R/G/B enable priority for accurate 60 Hz frame timing. Use Value: Enables 7.5%/11%/12.5% color time allocation per frame while maintaining white balance via EEPROM-stored current calibration - no host processor overhead required. |
Use Scenario: High-lumen micro-display illumination systems using discrete red/green/blue emitters with varying forward voltages. IC Role / Device Role / Timing Role: Integrated power management and current regulation IC delivering matched 700 mA drive with <±6% accuracy across temperature. Use Value: Reduces BOM count by integrating buck-boost converter, three drivers, fault monitoring, and NVM - simplifies thermal design with 95% peak efficiency. |
| Automotive HUD Backlighting | AR/VR Microdisplay Illumination |
Use Scenario: Head-up display units needing high-brightness, low-latency RGB backlight with robust fault reporting for functional safety. IC Role / Device Role / Timing Role: Fault-aware LED driver providing open/short detection, thermal shutdown, and UVLO monitoring with interrupt signaling via FAULT pin. Use Value: Meets ASIL-B readiness requirements through deterministic fault flagging and EEPROM-stored calibration - eliminates reliance on software diagnostics. |
Use Scenario: Next-generation near-eye displays requiring ultra-fast color switching and minimal EMI in tight form factors. IC Role / Device Role / Timing Role: High-frequency (2.4 MHz) buck-boost LED driver enabling <50 µs current rise/fall times for sub-millisecond color transitions. Use Value: Supports high-refresh-rate microdisplays (≥120 Hz) with precise current step control (0.64 mA resolution) and minimal PWM jitter. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar RGB sequential LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS61165RTVR | Single-channel 400 mA boost LED driver; no integrated RGB sequencing logic, no EEPROM, no fault flags | Requires external MCU for RGB timing and current control; suitable for simpler, lower-current applications | Choose when only one LED string is needed and system-level control is available |
| ISL97693IRTZ-T7A | Three-channel 300 mA linear LED driver; no integrated SMPS, higher power loss, no EEPROM, I²C-only control | Lacks buck-boost efficiency and standalone capability; limited to low-power, fixed-VF RGB arrays | Choose for cost-sensitive, low-heat applications where 300 mA/channel suffices and I²C bus is mandatory |
Compared with TPS61165RTVR and ISL97693IRTZ-T7A, LM3549SQE/NOPB uniquely integrates sequential timing logic, buck-boost conversion, EEPROM-based calibration, and comprehensive hardware fault detection - making it the only option for self-contained, high-efficiency, high-current RGB projector light engines.
Availability
LM3549SQE/NOPB is available at Aetrix Electronics and suitable for portable video projectors, RGB laser light engines, automotive HUD backlighting, AR/VR microdisplay illumination, and high-power LED driving applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM3549SQE/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, embedded processing, and logic ICs for industrial, automotive, and consumer applications.
The LM3549SQE/NOPB belongs to TI's high-efficiency LED driver product line, engineered specifically for sequential RGB illumination in portable projection and microdisplay systems where thermal efficiency, timing precision, and autonomous operation are critical.
FAQ
What is the primary function of the LM3549SQE/NOPB in a portable video projector?
The LM3549SQE/NOPB serves as the core sequential RGB LED driver, managing time-multiplexed red/green/blue illumination with hardware-enforced priority (R > G > B), dynamic buck-boost voltage adjustment, and EEPROM-stored current calibration. In portable video projectors, LM3549SQE/NOPB enables precise frame-based color sequencing without host processor intervention, directly supporting typical 7.5%/11%/12.5% time allocations per color while maintaining white balance stability across temperature.
How does the LM3549SQE/NOPB achieve standalone operation without an I²C interface?
The LM3549SQE/NOPB achieves standalone operation by storing calibrated current settings (for up to three banks) in internal non-volatile EEPROM. During startup, these values are automatically loaded into volatile registers, allowing full functionality-including sequential enable control via R_EN/G_EN/B_EN and global brightness via PWM-without any I²C communication. LM3549SQE/NOPB retains this capability even after power cycling, making it ideal for space-constrained projector modules lacking a dedicated I²C bus.
What fault conditions does the LM3549SQE/NOPB detect, and how are they reported?
The LM3549SQE/NOPB detects LED open, LED short, thermal shutdown (TSD), under-voltage lockout (UVLO), and buck-boost converter overcurrent (OCP). Each condition sets a corresponding bit in the read-only FAULT register (address 0x17) and, if unmasked, pulls the FAULT pin low (active-low open drain). Reading the FAULT register clears all flags and releases the FAULT pin. LM3549SQE/NOPB provides hardware-level fault isolation critical for projector reliability-no firmware polling required.
Can the LM3549SQE/NOPB drive multiple LEDs simultaneously, or is it strictly sequential?
The LM3549SQE/NOPB is strictly sequential: only one of R_OUT, G_OUT, or B_OUT can be active at any time, enforced by internal hardware logic that respects fixed priority (R > G > B). If a second enable input (e.g., G_EN) is asserted while the first (R_EN) remains high, the corresponding output (G_OUT) will not activate until R_EN goes low. This prevents simultaneous conduction, ensures safe timing in color-sequential systems, and is fundamental to LM3549SQE/NOPB's operation in portable video projectors.
What is the role of the VOUT pins (7 and 9) on the LM3549SQE/NOPB?
Pins 7 and 9 of the LM3549SQE/NOPB are parallel-connected buck-boost converter output terminals (VOUT), supplying dynamically adjusted voltage to the anodes of the RGB LEDs. The SMPS rapidly adapts VOUT to match the forward voltage of whichever LED is currently enabled (R, G, or B), minimizing power dissipation in the low-side drivers and maximizing system efficiency. Dual VOUT pins reduce impedance and improve current sharing, supporting the LM3549SQE/NOPB's 700 mA per channel capability with thermal integrity.
LM3549SQE/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Step-Down (Buck), Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 3
- Voltage - Supply (Min):
- 2.7V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 4.6V
- Current - Output / Channel:
- 705mA
- Frequency:
- 2.4MHz
- Dimming:
- I2C
- Applications:
- -
- Operating Temperature:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-WQFN (4x4)
LM3549SQE/NOPB FAQ
1.How can I place an order for LM3549SQE/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3549SQE/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 LM3549SQE/NOPB reliable?
The price and inventory of LM3549SQE/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3549SQE/NOPB is usually 5 days.
3.What payment methods are accepted for LM3549SQE/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3549SQE/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3549SQE/NOPB?
LM3549SQE/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3549SQE/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 LM3549SQE/NOPB?
For technical support, including LM3549SQE/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3549SQE/NOPB requirements.
6.How does Aetrix verify that LM3549SQE/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3549SQE/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 LM3549SQE/NOPB meets industry standards.
7.What is the process for return or replacement of LM3549SQE/NOPB?
All LM3549SQE/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3549SQE/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 LM3549SQE/NOPB part is unused and in its original packaging.
Return procedure for LM3549SQE/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3549SQE/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…
