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Texas Instruments LP8543SQX/NOPB
- Part No.:
- LP8543SQX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LP8543SQX/NOPB.pdf
- Description:
- IC LED DRV RGLTR PWM 60MA 24WQFN
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
LP8543SQX/NOPB from Texas Instruments is a 7-channel SMBus/I²C-controlled white LED driver with integrated 38V boost converter, adaptive output voltage control, and digital ambient light sensor interface. It delivers up to 60 mA per channel across 7 current sinks (OUT1–OUT7), supports 5.5V–22V input, and enables phase-shift PWM dimming for LCD backlighting in medium-sized displays (>10 inches).
For engineers reviewing the LP8543SQX/NOPB datasheet, LP8543SQX/NOPB pinout, LP8543SQX/NOPB application, or LP8543SQX/NOPB equivalent, key selection criteria include its 7-channel programmable current sink architecture, adaptive boost efficiency optimization, EEPROM-based ALS-to-backlight curve calibration, thermal regulation with temperature-threshold programming, and dual-group LED control (Display1/Display2) for main + sub-display configurations.
Technical Context
The LP8543SQX/NOPB integrates a high-voltage DC/DC boost converter (38V max, 0.12Ω RDS-ON) with adaptive output voltage control that dynamically adjusts VBOOST based on real-time LED string voltage demands. Its 7 independent current sinks support 0–60 mA per channel with ±3% output accuracy and ≤1.5% matching (OUT1–OUT6) at 20 mA.
Control is implemented via dual-mode serial interface (SMBus v2.0 or I²C, selectable via IF_SEL), external PWM input (0.1–25 kHz), or standalone operation. Phase-shift PWM (PSPWM) reduces peak battery current by staggered LED string activation, while internal EEPROM stores calibrated brightness curves, ALS compensation coefficients, and fault thresholds - all programmable without external voltages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 5.5V to 22V - supports 2×, 3×, or 4× Li-ion battery stacks with UVLO thresholds configurable for each configuration. |
| Boost Output Voltage | Up to 38V - includes overvoltage protection (VOV = VBOOST + 1.6V @ VBOOST ≥38V) and adaptive feedback for minimum-loss operation. |
| LED Current Sinks | 7 channels (OUT1–OUT7), 0–60 mA per channel with 0.23 mA step resolution - supports independent Display1 (4–7 strings) and Display2 (OUT7 only) grouping. |
| PWM Dimming Resolution | 10-bit at ≤4.5 kHz, 8-bit at 20 kHz - includes phase-shift PWM (PSPWM) to reduce boost converter load variance and improve system efficiency under VF mismatch. |
| Ambient Light Interface | Digital light-to-frequency ALS input (ALSI) with programmable prescaler and user-defined brightness-vs-light curve stored in EEPROM - ALSO output enables external sensor power control. |
| Thermal & Fault Protection | Internal thermal shutdown (TJ = 150°C), LED open/short detection per string, boost overcurrent limit (2.5 A max), and fault reporting via open-drain FAULT pin. |
| Package | WQFN-24 (4.0 mm × 4.0 mm × 0.8 mm, 0.5 mm pitch) - optimized for thermal dissipation (θJA = 35–50°C/W) in space-constrained backlight modules. |
Pinout & Package
LP8543SQX/NOPB uses a 24-pin WQFN package (4.0 × 4.0 × 0.8 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are validated per TI SNVS604D Rev. March 2013 datasheet.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND_SW (Pin 1) | Boost ground reference | Separate ground return for high-current boost switch node - must be routed with low-inductance path to minimize switching noise. |
| PWM (Pin 2) | External PWM dimming input | Accepts 0.1–25 kHz signal; low state disables device in stand-alone mode - requires GND tie if unused. |
| IF_SEL (Pin 3) | Interface mode select | High = SMBus v2.0, Low = I²C-compatible - determines timing compliance and address handling logic. |
| EN (Pin 4) | Enable control | Active-high enable with UVLO hysteresis - disables all circuitry including LDO and boost when pulled low. |
| ALSI (Pin 5) | ALS frequency input | Accepts light-to-frequency sensor output (0.2–2000 kHz); must be tied to GND if ALS not used. |
| ALSO (Pin 6) | ALS enable output | Open-drain active-high output to power external sensor - polarity and timing programmable via EEPROM. |
| FAULT (Pin 7) | Fault status indicator | Open-drain active-low output asserting on LED open/short, boost overcurrent, or thermal shutdown - latched until cleared. |
| VDDIO (Pin 8) | Digital I/O supply | 1.65–5.5V reference for SCLK/SDA/ADR/IF_SEL/PWM/EN - powers internal logic and SMBus/I²C transceivers. |
| GND_S (Pin 9) | Signal ground | Reference for analog inputs (FB, ALSI), digital I/O, and internal LDO - separate from GND_SW and GND_L for noise isolation. |
| SCLK (Pin 10) | Serial clock input | I²C/SMBus clock line - must be tied to GND if interface unused; supports 400 kHz (I²C) or 100 kHz (SMBus) max. |
| SDA (Pin 11) | Serial data I/O | Bidirectional I²C/SMBus data line - open-drain with internal pull-up; requires external pull-up if used in multi-master systems. |
| OUT1–OUT6 (Pins 12–14, 16–18) | Current sink outputs | Individually controllable LED drivers (0–60 mA); OUT1–OUT6 form Display1 group - unused pins may float. |
| GND_L (Pin 15) | LED sink ground | Dedicated ground return for OUT1–OUT7 - must be connected to low-impedance plane to maintain current accuracy and thermal stability. |
| OUT7 (Pin 19) | Independent current sink | Configurable as Display2 (sub-display/backlight) or extended Display1 string - has separate current/PWM registers and fault reporting. |
| ADR (Pin 20) | I²C/SMBus address select | Configures slave address bits (A1/A0); must be tied to GND if single-device bus or default address used. |
| FB (Pin 21) | Boost feedback input | Resistive divider input for VBOOST regulation - sets target output voltage or enables adaptive control via register. |
| VLDO (Pin 22) | LDO output | 5.0V ±0.5V regulated output (4.5–5.5V) capable of sourcing 5 mA - requires 470 nF ceramic capacitor to GND. |
| VIN (Pin 23) | Main power input | 5.5–22V supply for boost converter and internal LDO - bypassed with 10 µF low-ESR ceramic capacitor. |
| SW (Pin 24) | Boost switch node | High-side FET drain connection - connects to inductor (L1) and flyback diode (D1); requires tight layout to minimize EMI. |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive Boost Voltage Control | Reduces power loss by dynamically lowering VBOOST to the minimum required level across varying LED forward voltage mismatches and brightness levels. |
| Phase-Shift PWM (PSPWM) | Staggers ON-times of LED strings to lower peak battery current and stabilize boost loading - improves efficiency by up to 15% vs. conventional PWM under VF mismatch. |
| EEPROM-Based Calibration | Stores factory-trimmed LED current defaults, ALS-to-backlight transfer curves, fault thresholds, and temperature regulation setpoints - eliminates post-assembly trimming. |
| Dual-Group LED Control | Supports independent current, PWM, and fault monitoring for Display1 (OUT1–OUT6) and Display2 (OUT7), enabling main + sub-display backlighting with one IC. |
| Integrated 5V LDO | Supplies 5 mA at 5.0V for external ALS sensors or logic - automatically disabled in standby to reduce quiescent current to 1 µA. |
| Comprehensive Fault Detection | Reports open-circuit, short-circuit (≥2 LEDs), and thermal faults per string via STATUS register and FAULT pin - thresholds programmable in EEPROM. |
Applications
| Automotive Infotainment Displays | Industrial HMI Panels |
|---|---|
|
Use Scenario: 12-inch TFT-LCD dashboard display in automotive infotainment system operating from 12V battery with wide temperature range (−40°C to +85°C). IC Role / Device Role / Timing Role: LP8543SQX/NOPB serves as primary backlight driver controlling 6 LED strings (Display1) with ambient light compensation and thermal derating. Use Value: Adaptive boost and PSPWM maintain >85% efficiency across battery voltage sag (down to 9V) and LED aging, reducing thermal stress on display module. |
Use Scenario: 15-inch ruggedized HMI panel in factory automation equipment requiring reliable backlight operation under vibration and EMI exposure. IC Role / Device Role / Timing Role: LP8543SQX/NOPB drives 7 LED strings (Display1 + Display2) with independent dimming for main UI and status indicators. Use Value: Dual-group control eliminates need for second LED driver IC; EEPROM-stored calibration ensures consistent brightness across production batches. |
| Medical Diagnostic Monitors | Commercial Digital Signage |
|
Use Scenario: 19-inch medical-grade monitor used in imaging workstations where precise grayscale reproduction and flicker-free dimming are critical. IC Role / Device Role / Timing Role: LP8543SQX/NOPB provides 8-bit current control and 19.5 kHz PWM dimming for Display1, with OUT7 reserved for emergency status backlight. Use Value: ±3% current accuracy and <1.5% string matching ensure uniform luminance across display area - essential for DICOM-compliant grayscale rendering. |
Use Scenario: Outdoor kiosk display exposed to direct sunlight and ambient temperature extremes, requiring automatic brightness adjustment. IC Role / Device Role / Timing Role: LP8543SQX/NOPB interfaces with digital ALS via ALSI/ALSO pins and executes user-programmed brightness-vs-light curve stored in EEPROM. Use Value: Programmable ALS response eliminates external microcontroller dependency for ambient adaptation - reduces BOM count and firmware complexity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar white LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS61165DRVR | Single-channel 40V boost LED driver with 1.2A switch; no integrated ALS interface, no EEPROM, no multi-string current sinks. | Requires external MCU for ALS processing and multi-string coordination; suited for simpler, lower-channel-count designs. | Choose TPS61165DRVR when only one high-current LED string is needed and system-level control is already available. |
| LM3409QMH/NOPB | Adjustable-current buck-boost LED controller (no integrated FET); requires external MOSFET, inductor, and sense resistor - no ALS or EEPROM. | Targeted at high-power, thermally demanding LED arrays where discrete component selection is prioritized over integration. | Choose LM3409QMH/NOPB when design requires >60 mA per string, wide input range beyond 22V, or custom thermal management. |
Compared with TPS61165DRVR and LM3409QMH/NOPB, the LP8543SQX/NOPB uniquely integrates 7 precision current sinks, adaptive boost, ALS interface, and EEPROM-based calibration in a single WQFN package - eliminating external components and firmware overhead for medium-size LCD backlight systems.
Availability
LP8543SQX/NOPB is available at Aetrix Electronics and suitable for automotive infotainment displays, industrial HMI panels, medical diagnostic monitors, and commercial digital signage requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LP8543SQX/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 over 50 years of innovation in high-reliability IC design.
The LP8543SQX/NOPB belongs to TI's LED backlight driver product line, engineered specifically for energy-efficient, compact, and intelligent LCD backlight control in medium-format displays where integration, thermal robustness, and ambient adaptability are critical.
FAQ
What is the maximum number of LED strings supported by the LP8543SQX/NOPB?
The LP8543SQX/NOPB supports up to seven independent LED current sinks (OUT1–OUT7). These can be configured as either four to seven strings for Display1 (main backlight) and optionally one dedicated string (OUT7) for Display2 (sub-display or status lighting), with EEPROM-defined grouping and independent control registers for each group.
Does the LP8543SQX/NOPB require external components for boost converter operation?
Yes - the LP8543SQX/NOPB requires an external inductor (L1), flyback diode (D1), input capacitor (CIN = 10 µF), output capacitor (COUT = 4.7 µF), and VLDO bypass capacitor (470 nF). The boost FET and compensation network are fully integrated, eliminating need for external MOSFETs or op-amps.
How does the phase-shift PWM (PSPWM) feature improve efficiency in the LP8543SQX/NOPB?
PSPWM in the LP8543SQX/NOPB staggers the ON-time of LED strings to reduce simultaneous current draw. When strings with higher forward voltage are turned off, the boost converter lowers its output voltage - minimizing conduction losses. This dynamic adaptation improves system efficiency by up to 15% under real-world VF mismatch conditions.
Can the LP8543SQX/NOPB operate without a microcontroller?
Yes - the LP8543SQX/NOPB supports stand-alone operation using only the PWM input pin for brightness control and EN for on/off sequencing. In this mode, it uses factory-calibrated EEPROM settings for current, ALS response, and thermal limits - requiring no external MCU or firmware.
What ambient light sensors are compatible with the LP8543SQX/NOPB ALS interface?
The LP8543SQX/NOPB ALS interface is designed for digital light-to-frequency (LTF) sensors such as the OPT3001 or TSL2561. These sensors output a square wave whose frequency scales with illuminance; the LP8543SQX/NOPB measures this frequency on ALSI and applies user-programmed compensation curves stored in EEPROM.
LP8543SQX/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)
LP8543SQX/NOPB FAQ
1.How can I place an order for LP8543SQX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP8543SQX/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 LP8543SQX/NOPB reliable?
The price and inventory of LP8543SQX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP8543SQX/NOPB is usually 5 days.
3.What payment methods are accepted for LP8543SQX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP8543SQX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP8543SQX/NOPB?
LP8543SQX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP8543SQX/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 LP8543SQX/NOPB?
For technical support, including LP8543SQX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP8543SQX/NOPB requirements.
6.How does Aetrix verify that LP8543SQX/NOPB is sourced from the original manufacturer or authorized distributors?
All LP8543SQX/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 LP8543SQX/NOPB meets industry standards.
7.What is the process for return or replacement of LP8543SQX/NOPB?
All LP8543SQX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP8543SQX/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 LP8543SQX/NOPB part is unused and in its original packaging.
Return procedure for LP8543SQX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LP8543SQX/NOPB Tags
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BCR402RE6327HTSA1
Infineon Technologies
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BCR430UXTSA2
Infineon Technologies
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BCR420UE6433HTMA1
Infineon Technologies
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BCR420UE6327HTSA1
Infineon Technologies
-
BCR421UE6327HTSA1
Infineon Technologies
-
LYT1604D-TL
Power Integrations
-
HV9910CLG-G
Microchip Technology
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CL2N8-G
Microchip Technology
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BCR420UW6-7
Diodes Incorporated
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BCR421UW6-7
Diodes Incorporated
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BCR420UFD-7
Diodes Incorporated
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BCR421UFD-7
Diodes Incorporated
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