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Texas Instruments LP8543SQE/NOPB
- Part No.:
- LP8543SQE/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LP8543SQE/NOPB.pdf
- Description:
- IC LED DRV RGLTR PWM 60MA 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,120
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Product details
Overview
LP8543SQE/NOPB from Texas Instruments is a SMBus/I²C-controlled white LED driver IC with integrated 38 V boost converter and seven programmable current-sink outputs for medium-sized LCD backlighting. It delivers up to 60 mA per channel, supports adaptive boost voltage control, phase-shift PWM dimming, and digital ambient light sensor interface - enabling high-efficiency, temperature-aware, and ALS-compensated backlight management in portable displays.
For engineers reviewing the LP8543SQE/NOPB datasheet, LP8543SQE/NOPB pinout, LP8543SQE/NOPB application, or LP8543SQE/NOPB equivalent, key selection considerations include its 5.5–22 V input range, WQFN-24 package, 7-channel independent current control, EEPROM-based calibration, and dual-mode (SMBus/I²C) serial interface compatibility.
Technical Context
The LP8543SQE/NOPB integrates a high-voltage DC/DC boost converter (up to 38 V output) with adaptive feedback based on real-time LED string voltage monitoring, minimizing power loss across varying forward voltage mismatches. Its phase-shift PWM (PSPWM) architecture dynamically cycles individual LED strings off to lower required boost voltage and reduce peak battery current.
It implements dual-group LED control (Display1: OUT1–OUT6; Display2: OUT7), each with independent 8-bit current (0–60 mA) and PWM registers, plus programmable fault thresholds, thermal regulation, and EEPROM-stored ambient light-to-brightness transfer curves - all configurable via SMBus or I²C interface with IF_SEL pin selection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 5.5 V to 22 V - supports 2× to 4× Li-ion battery stacks without external pre-regulation. |
| Boost Output Voltage | Up to 38 V - sufficient for driving up to 10 LEDs in series per string at typical VF. |
| LED Current Range | 0–60 mA per channel (8-bit resolution, 0.23 mA step) - enables precise bin-matching and panel-to-panel brightness uniformity. |
| PWM Dimming Frequency | 229 Hz to 19.5 kHz - avoids audible noise while supporting high-speed camera capture and flicker-free viewing. |
| Phase-Shift PWM Support | Yes - reduces boost voltage and peak input current when LED VF mismatch exists, improving system efficiency by up to 15% vs. conventional PWM. |
| Ambient Light Interface | Digital light-to-frequency sensor input (ALSI) with user-programmable compensation curve - eliminates external ADC and simplifies ALS integration. |
| Thermal Protection | Internal junction temperature sensing with programmable dimming threshold - prevents LED degradation and ensures long-term reliability in enclosed displays. |
Pinout & Package
LP8543SQE/NOPB is housed in a thermally enhanced 4 mm × 4 mm × 0.8 mm WQFN-24 package with 0.5 mm pitch and exposed thermal pad (GND_L). The package supports high-power dissipation (θJA = 35–50°C/W) and compact layout for space-constrained display modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND_SW, GND_S, GND_L | Ground terminals | Separate ground paths for boost switch, signal logic, and LED sinks - minimize noise coupling and improve current-sink accuracy. |
| VIN | Main power input | Accepts 5.5–22 V supply; powers boost stage and internal LDO - no external regulator needed. |
| SW, FB, VLDO | Boost converter nodes | SW drives external inductor; FB sets regulated boost output; VLDO provides stable 4.5–5.5 V for ALS and logic. |
| OUT1–OUT7 | Current sink outputs | Seven independent, 60 mA-capable sinks - OUT1–OUT6 for main display, OUT7 configurable for sub-display or status lighting. |
| PWM, EN, IF_SEL, ADR | Control inputs | PWM enables stand-alone dimming; EN enables/disables chip; IF_SEL selects SMBus vs. I²C; ADR sets slave address. |
| SCLK, SDA | I²C/SMBus interface | Standard two-wire bus compliant with 400 kHz I²C and 100 kHz SMBus - supports daisy-chaining and host MCU control. |
| ALSI, ALSO, FAULT | ALS & fault signaling | ALSI accepts frequency-modulated ALS output; ALSO enables external sensor; FAULT is open-drain fault indicator (short/open LED). |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive Boost Voltage Control | Reduces boost output to minimum required level based on real-time LED string voltage - cuts power loss and heat generation in mismatched LED arrays. |
| Phase-Shift PWM (PSPWM) | Sequentially disables LED strings to lower effective boost demand - improves efficiency up to 15% and smooths battery current draw during dimming. |
| On-Chip EEPROM Calibration | Stores factory-set current values, ALS response curves, thermal thresholds, and output configurations - eliminates post-assembly trimming and ensures unit-to-unit consistency. |
| Dual-Group LED Control | Independent current and PWM registers for Display1 (OUT1–OUT6) and Display2 (OUT7) - enables main + sub-display backlighting with no extra ICs. |
| Integrated 5 V LDO | Supplies up to 5 mA for external ALS sensors - removes need for separate bias rail and simplifies BOM. |
Applications
| Tablet Backlight Control | Industrial HMI Display |
|---|---|
Use Scenario: 10.1-inch tablet with 6-string edge-lit LED backlight requiring consistent brightness across operating temperature and ambient light conditions. IC Role / Device Role / Timing Role: LP8543SQE/NOPB acts as primary backlight controller, managing boost conversion, per-string current regulation, ALS-driven dynamic dimming, and thermal derating. Use Value: Adaptive boost and PSPWM reduce average power consumption by 12% versus fixed-voltage drivers, extending battery runtime without compromising visual quality. | Use Scenario: Ruggedized industrial panel PC operating in −40°C to +85°C environments with variable ambient lighting and strict EMI requirements. IC Role / Device Role / Timing Role: LP8543SQE/NOPB serves as fault-aware, temperature-compensated LED driver with EEPROM-stored calibration - ensuring stable luminance over lifetime and temperature drift. Use Value: Integrated open/short LED detection and programmable fault thresholds eliminate external monitoring circuitry, reducing board area and qualification effort. |
| Laptop Main Display | Medical Diagnostic Monitor |
Use Scenario: 13.3-inch laptop display needing flicker-free, low-noise backlight dimming across full brightness range with ALS auto-adjustment. IC Role / Device Role / Timing Role: LP8543SQE/NOPB provides 19.5 kHz PWM dimming, phase-shift operation, and digital ALS interface - meeting stringent flicker and EMC standards. Use Value: High-frequency PWM combined with PSPWM eliminates audible coil whine and minimizes conducted EMI, easing system-level compliance testing. | Use Scenario: DICOM-compliant medical monitor requiring calibrated, stable backlight luminance for accurate grayscale rendering under clinical lighting conditions. IC Role / Device Role / Timing Role: LP8543SQE/NOPB functions as precision-calibrated backlight engine, using EEPROM-stored current defaults and ALS compensation curves to maintain luminance uniformity. Use Value: Factory-trimmed 8-bit current control (±3% accuracy) and matching ≤1.35% between OUT1–OUT6 ensures consistent brightness across all LED strings - critical for diagnostic image fidelity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar white LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3409MH/NOPB | External MOSFET controller (no integrated FET); requires external current sense and gate drive; no EEPROM or ALS interface. | Targeted at high-current, discrete LED driver designs where flexibility outweighs integration - lacks built-in ALS, thermal regulation, or multi-string synchronization. | Choose LM3409MH/NOPB only when designing custom high-power (>1 A) LED systems requiring external FET optimization and thermal design freedom. |
| TPS61165DRVR | Single-output WLED driver with integrated 40 V boost; no multi-string current sinks, no ALS interface, no EEPROM, no phase-shift PWM. | Designed for small displays (<7″) with single LED string - lacks channel independence, fault reporting, and ambient light adaptation. | Use TPS61165DRVR for cost-sensitive, single-string applications where advanced features like PSPWM, ALS, or thermal dimming are unnecessary. |
Compared with LM3409MH/NOPB and TPS61165DRVR, LP8543SQE/NOPB uniquely combines 7-channel current sinking, adaptive boost, phase-shift PWM, on-chip ALS interface, and EEPROM calibration - making it the only option among the three suitable for medium-sized, feature-rich, production-ready LCD backlights requiring long-term luminance stability and minimal external components.
Availability
LP8543SQE/NOPB is available at Aetrix Electronics and suitable for tablet backlight control, industrial HMI displays, laptop main displays, medical diagnostic monitors, and automotive infotainment systems requiring stable component supply, long lifecycle support, and qualified automotive-grade alternatives.
Supply support for LP8543SQE/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 leader specializing in analog, embedded processing, and power management technologies - with decades of expertise in display power solutions and automotive-qualified IC design.
The LP8543SQE/NOPB belongs to TI's WLED driver product line, engineered specifically for energy-efficient, intelligent backlight control in medium-format LCD panels - emphasizing thermal resilience, ALS adaptability, and factory-calibrated consistency.
FAQ
What is the maximum number of LEDs LP8543SQE/NOPB can drive per string?
LP8543SQE/NOPB supports up to 10 LEDs in series per string when operated at its maximum boost output voltage of 38 V and typical white LED forward voltage of ~3.8 V. This is confirmed in the Typical Application section of the SNVS604D datasheet, which states "UP TO 10 LEDS" for Display2 (OUT7) and "UP TO 70 LEDS" total across all strings - implying 7 strings × 10 LEDs maximum. The actual count depends on VF distribution and thermal derating.
Does LP8543SQE/NOPB support both I²C and SMBus protocols simultaneously?
No - LP8543SQE/NOPB supports either I²C or SMBus, selected by the IF_SEL pin: low for I²C-compatible mode (400 kHz max clock), high for SMBus mode (100 kHz max clock). Both protocols share the same SCLK/SDA pins and register map, but timing and voltage thresholds differ per specification. The LP8543SQE/NOPB does not auto-detect or switch between them dynamically.
How is ambient light sensing implemented in LP8543SQE/NOPB?
LP8543SQE/NOPB implements ambient light sensing via the ALSI pin, which accepts frequency-modulated output from light-to-frequency sensors (e.g., TAOS TSL256x). The internal counter measures input frequency to derive lux level; coefficients for the ALS-to-backlight brightness curve are stored in EEPROM and applied in real time. ALSO pin provides programmable active-high/low enable for the external sensor.
Can LP8543SQE/NOPB operate without an external microcontroller?
Yes - LP8543SQE/NOPB supports stand-alone operation using the PWM pin for brightness control and EN pin for on/off sequencing. In this mode, it uses internal EEPROM-stored current and PWM settings, eliminating the need for continuous host communication. The datasheet confirms this in "Typical Application, Stand-Alone Mode" and Section 8.3.1.
What protection features does LP8543SQE/NOPB include for LED string faults?
LP8543SQE/NOPB includes open-circuit and short-circuit LED fault detection on all seven outputs. Fault thresholds are EEPROM-programmable, and detection results appear in the STATUS register and on the open-drain FAULT pin. It detects single-LED shorts when VF variation is low, and multi-LED shorts or open strings regardless - enabling manufacturing test and field diagnostics without external circuitry.
LP8543SQE/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-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 7
- Voltage - Supply (Min):
- 5.5V
- Voltage - Supply (Max):
- 22V
- Voltage - Output:
- 40V
- Current - Output / Channel:
- 60mA
- Frequency:
- 625kHz ~ 1.25MHz
- Dimming:
- PWM
- Applications:
- Backlight
- Operating Temperature:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-WQFN (4x4)
LP8543SQE/NOPB FAQ
1.How can I place an order for LP8543SQE/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP8543SQE/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 LP8543SQE/NOPB reliable?
The price and inventory of LP8543SQE/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP8543SQE/NOPB is usually 5 days.
3.What payment methods are accepted for LP8543SQE/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP8543SQE/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP8543SQE/NOPB?
LP8543SQE/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP8543SQE/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 LP8543SQE/NOPB?
For technical support, including LP8543SQE/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP8543SQE/NOPB requirements.
6.How does Aetrix verify that LP8543SQE/NOPB is sourced from the original manufacturer or authorized distributors?
All LP8543SQE/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 LP8543SQE/NOPB meets industry standards.
7.What is the process for return or replacement of LP8543SQE/NOPB?
All LP8543SQE/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP8543SQE/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 LP8543SQE/NOPB part is unused and in its original packaging.
Return procedure for LP8543SQE/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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