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Texas Instruments LM27966SQX/NOPB
- Part No.:
- LM27966SQX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM27966SQX/NOPB.pdf
- Description:
- IC LED DRV RGLTR I2C 30MA 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,640
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Product details
Overview
LM27966SQX/NOPB from Texas Instruments is a highly integrated, I²C-compatible white LED driver IC with adaptive 1×/1.5× charge pump architecture. It delivers up to 180mA total output current across two independently controlled banks - five main-display LEDs (D1–D5) at ≤30mA each and one auxiliary LED (DAUX) - with 0.3% typical current matching and 91% peak efficiency. It operates from 2.7V to 5.5V input and targets compact mobile display backlighting.
For engineers reviewing the LM27966SQX/NOPB datasheet, LM27966SQX/NOPB pinout, LM27966SQX/NOPB application, or LM27966SQX/NOPB equivalent, key selection criteria include its dual-bank I²C brightness control (32 levels for main, 4 analog for AUX), resistor-programmable full-scale current via ISET/RSET, adaptive gain switching based on LED forward voltage sensing, and WQFN-24 package thermal performance.
Technical Context
The LM27966SQX/NOPB implements an adaptive CMOS charge pump that dynamically selects between 1× (pass-mode) and 1.5× gain based on real-time monitoring of VDX voltage across D1–D4 pins - transitioning at ~175mV headroom threshold to maintain regulation without inductor. Its internal current sinks use a 1.25V reference and 200× current gain ratio (IDx = 200 × 1.25V / RSET) to set precise LED drive levels.
It features separate I²C registers for main display (0xA0, 32-step PWM + analog scaling at 20kHz) and auxiliary LED (0xC0, 4-level analog only), with hardware RESET pin (active-low) enabling system-level disable independent of bus communication. The device includes thermal shutdown (170°C trip) and supports common-anode LED configurations with dedicated POUT, VIN, GND, and flying capacitor (C1/C2) connections.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.7V to 5.5V - supports single-cell Li-ion battery operation across full discharge curve. |
| Total Output Current | 180mA max - distributed across up to six LEDs (5× main + 1× AUX), with per-pin limit of 30mA. |
| LED Current Matching | 0.3% typical - ensures uniform brightness across main-display LEDs under varying temperature and supply conditions. |
| Charge Pump Efficiency | 91% peak - achieved via adaptive 1×/1.5× gain selection minimizing power loss during pass-mode operation. |
| I²C Interface | Standard-mode compatible (36h slave address) - enables independent brightness control of main and AUX banks using SCL/SDIO/VIO pins. |
| Package | WQFN-24 (4mm × 4mm × 0.8mm, RTW0024A) - low-profile leadless package with exposed DAP for thermal dissipation (θJA = 41.3°C/W). |
| Operating Junction Temp | –30°C to +100°C - validated for consumer handheld environments with thermal shutdown at 170°C. |
Pinout & Package
LM27966SQX/NOPB uses a 24-pin Quad WQFN package (RTW0024A) with wettable flank leads and thermally enhanced DAP (pin 9/18/DAP). The exposed pad must be soldered to PCB ground plane for optimal thermal performance and EMI reduction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (24) | Main power input | Accepts 2.7V–5.5V supply; powers charge pump and internal circuitry. |
| POUT (23) | Regulated charge pump output | Provides boosted voltage (1× or 1.5× VIN) to LED anodes; requires external COUT. |
| D1–D5 (12–16) | Main display current sink outputs | Individually controlled constant-current sinks (≤30mA each); support forward-voltage sensing for gain control. |
| DAUX (3) | Auxiliary LED current sink | Independent 4-level analog-controlled sink for indicator/status lighting; no voltage sensing. |
| ISET (17) | Current reference programming node | Connect RSET to GND to set full-scale LED current: IDx = 200 × 1.25V / RSET. |
| SCL (1), SDIO (2), VIO (7) | I²C interface signals | Support standard-mode communication; VIO sets logic level (1.4V–VIN) for bus compatibility. |
| RESET (10) | Hardware reset input | Active-low signal forcing all registers to default state and disabling all outputs immediately. |
| GND (9, 18, DAP) | Ground reference | Three dedicated ground connections plus exposed DAP for low-impedance return path and thermal conduction. |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive 1×/1.5× charge pump | Switches gain automatically based on D1–D4 voltage sensing to maximize efficiency across input range - avoids fixed-gain inefficiency. |
| Dual independent LED banks | Main display (5× PWM/analog dimming) and AUX (4-level analog only) enable simultaneous but differentiated lighting control without external logic. |
| 0.3% LED current matching | Ensures consistent luminance across multi-LED displays without manual calibration or binning compensation. |
| Resistor-programmable full-scale current | RSET selection directly sets absolute current level (e.g., 16.9kΩ → 15mA per Dx), decoupling design from process variation. |
| Hardware RESET with fast recovery | Enables deterministic system-level fault recovery (<250µs start-up after reset release) independent of I²C bus state. |
Applications
| Mobile Phone Main Display Backlight | PDA Front Panel Indicator Lighting |
|---|---|
Use Scenario: Driving 5 parallel white LEDs behind a TFT-LCD panel in a smartphone with variable ambient light conditions. IC Role / Device Role / Timing Role: Constant-current LED driver with adaptive charge pump gain and I²C brightness control register (0xA0). Use Value: Maintains uniform brightness across display while extending battery life via 91% peak efficiency and 1× pass-mode operation above 3.6V input. |
Use Scenario: Illuminating status LEDs (power, charging, notification) on a handheld PDA with minimal PCB area. IC Role / Device Role / Timing Role: Auxiliary current sink (DAUX) with 4-level analog dimming controlled via I²C register 0xC0. Use Value: Eliminates need for discrete current-limiting resistors and separate dimming circuitry, reducing BOM count and layout complexity. |
| Compact Portable Media Player UI Lighting | Industrial Handheld Terminal Display Enhancement |
Use Scenario: Backlighting segmented OLED or LCD user interface elements in a media player with tight thermal constraints. IC Role / Device Role / Timing Role: Dual-bank driver delivering 150mA to main UI and 30mA to status indicators, managed via shared I²C bus. Use Value: Enables synchronized dimming transitions and eliminates visible flicker using 20kHz PWM frequency on main bank. |
Use Scenario: Providing reliable, matched LED illumination for ruggedized industrial terminal displays operating across –30°C to +85°C ambient. IC Role / Device Role / Timing Role: Thermally robust WQFN-24 LED driver with internal thermal shutdown (170°C) and validated –30°C to +100°C junction range. Use Value: Ensures continuous operation under high-power display loads without derating or external thermal management components. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar white LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3530TMX/NOPB | 6-channel I²C LED driver with 12-bit linear dimming; no adaptive charge pump - uses fixed 1.5× boost only. | Lacks 1× pass-mode efficiency; higher quiescent current (3.5mA vs 3.32mA); supports more channels but lower per-channel current (25mA vs 30mA). | Choose when finer brightness resolution (4096 steps) outweighs efficiency trade-off and 30mA/channel is not required. |
| TPS61165DRVR | Single-output boost LED driver with analog/PWM dimming; no I²C interface - uses EN/CTRL pins for brightness control. | No multi-bank capability; requires external MOSFET for >30mA; lacks voltage-sensing gain adaptation and current matching spec. | Choose for cost-sensitive single-LED applications where I²C control and matched multi-LED performance are unnecessary. |
Compared with LM3530TMX/NOPB and TPS61165DRVR, LM27966SQX/NOPB uniquely combines adaptive gain switching, dual independent banks with differential dimming methods, and guaranteed 0.3% current matching - making it optimal for space-constrained, battery-powered displays requiring both efficiency and visual consistency.
Availability
LM27966SQX/NOPB is available at Aetrix Electronics and suitable for mobile phone display lighting, PDA backlighting, and general LED lighting applications requiring stable component supply, long-term production continuity, and RoHS-compliant packaging.
Supply support for LM27966SQX/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 leadership in precision analog and low-power IC design.
The LM27966SQX/NOPB belongs to TI's white LED driver product line, engineered specifically for high-efficiency, multi-bank backlighting in portable consumer electronics where battery life, thermal performance, and display uniformity are critical.
FAQ
What is the maximum LED forward voltage supported by LM27966SQX/NOPB?
The LM27966SQX/NOPB supports LED forward voltages from 2.0V to 4.0V per diode. Its adaptive 1×/1.5× charge pump maintains regulation across this range by switching gain when any active Dx pin voltage drops to ~175mV - ensuring sufficient headroom (VPOUT − VLED) for current source operation. At 3.6V LED VF and 3.6V VIN, the device operates in 1× mode; below ~3.2V VIN, it transitions to 1.5× mode to sustain 30mA per channel.
How do I configure LM27966SQX/NOPB for 25mA per main-display LED?
To set 25mA per main-display LED on LM27966SQX/NOPB, calculate RSET using IDx = 200 × 1.25V / RSET → RSET = 200 × 1.25V / 0.025A = 10.0kΩ. Place a 10.0kΩ ±1% resistor between ISET (pin 17) and GND. Confirm operation by measuring VSET at ISET - it must be 1.25V ±2%. Then enable D1–D5 via General Purpose Register (0x10, bit EN-MAIN = 1) and set brightness level via Main Display Brightness Control Register (0xA0).
Does LM27966SQX/NOPB require external flying capacitors, and what values are recommended?
Yes, LM27966SQX/NOPB requires two external flying capacitors (C1 and C2) connected to pins 19/20 and 21/22 respectively. TI recommends 1.0µF X5R ceramic capacitors rated ≥6.3V (e.g., TDK C1608X5R1A105K or equivalent). These capacitors enable charge transfer in the 1.5× boost stage and must be placed close to the IC with short, low-inductance traces to minimize switching noise and ensure stable regulation.
Can LM27966SQX/NOPB drive a single high-current LED using paralleled outputs?
Yes, LM27966SQX/NOPB supports paralleling D1–D5 outputs to drive one high-current LED - for example, 5× 12mA sinks deliver 60mA total. To do so, connect all Dx pins together and select RSET for 12mA per sink (RSET = 200 × 1.25V / 0.012A ≈ 20.8kΩ). Ensure DAUX is disabled if unused, and ground D5 while clearing EN-D5 in the General Purpose Register to preserve adaptive gain switching for remaining pins.
What I²C address does LM27966SQX/NOPB use, and how is brightness controlled?
LM27966SQX/NOPB uses a fixed 7-bit I²C slave address of 0x36 (0110110b). Brightness is controlled via two dedicated registers: Main Display Brightness Control Register (0xA0) offers 32 discrete levels using combined PWM (20kHz) and analog scaling, while Auxiliary LED Brightness Control Register (0xC0) provides 4 analog-only levels (20%, 40%, 70%, 100%). Both registers are written after sending START, chip address (0x36), register address, and data byte.
LM27966SQX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Switched Capacitor (Charge Pump)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 6
- Voltage - Supply (Min):
- 2.7V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 2V ~ 4V
- Current - Output / Channel:
- 30mA
- Frequency:
- 1.27MHz
- Dimming:
- I2C
- Applications:
- Backlight
- Operating Temperature:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-WQFN (4x4)
LM27966SQX/NOPB FAQ
1.How can I place an order for LM27966SQX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM27966SQX/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 LM27966SQX/NOPB reliable?
The price and inventory of LM27966SQX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM27966SQX/NOPB is usually 5 days.
3.What payment methods are accepted for LM27966SQX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM27966SQX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM27966SQX/NOPB?
LM27966SQX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM27966SQX/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 LM27966SQX/NOPB?
For technical support, including LM27966SQX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM27966SQX/NOPB requirements.
6.How does Aetrix verify that LM27966SQX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM27966SQX/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 LM27966SQX/NOPB meets industry standards.
7.What is the process for return or replacement of LM27966SQX/NOPB?
All LM27966SQX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM27966SQX/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 LM27966SQX/NOPB part is unused and in its original packaging.
Return procedure for LM27966SQX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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