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Texas Instruments LP8556SQE-E00/NOPB
- Part No.:
- LP8556SQE-E00/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LP8556SQE-E00/NOPB.pdf
- Description:
- IC LED DRV RGLTR PWM 25MA 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:250
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Product details
Overview
LP8556SQE-E00/NOPB from Texas Instruments is a high-efficiency LED backlight driver IC featuring an integrated asynchronous boost converter and six precision current sinks for tablet LCD backlighting. It supports 2.7 V–20 V input, delivers up to 43 V boost output, configures 5-channel operation with 23 mA per channel, and enables PWM or I²C brightness control in a 24-pin WQFN package.
For engineers reviewing the LP8556SQE-E00/NOPB datasheet, LP8556SQE-E00/NOPB pinout, LP8556SQE-E00/NOPB application, or LP8556SQE-E00/NOPB equivalent, this device is selected for space-constrained tablet designs requiring adaptive voltage headroom control, phase-shifted PWM dimming, and robust fault protection including LED open/short detection and 6-level OVP.
Technical Context
The LP8556SQE-E00/NOPB implements an adaptive-output-voltage boost converter with CPM (current-programmed mode) control, using internal 20-MHz oscillator-derived switching frequencies of 312 kHz, 625 kHz, or 1250 kHz-set via EPROM configuration (not external resistor). Its six current sinks operate with ≤0.5% matching at 23 mA and support 15-bit PWM dimming resolution with phase-shifted timing to reduce audible noise.
It integrates a 0.19-Ω internal MOSFET switch, programmable slew-rate control on SW pin (1.9–7.5 V/ns), spread-spectrum modulation (±1% ΔtON/tSW), and full safety monitoring: UVLO (2.5 V/5.2 V thresholds), thermal shutdown (150°C), OCP (up to 2.6 A), and six programmable OVP levels referenced to VBOOST.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.7 V to 20 V - powers directly from multi-cell Li-ion battery or regulated rail; LDO input stage enables stable internal biasing. |
| Boost Output Range | 16 V to 34.5 V - factory-configured VBOOST_RANGE=1 and VBOOST_MAX=101; minimizes power loss by dynamically tracking LED string forward voltage. |
| LED Channel Count | 5 channels - fixed configuration for LP8556SQE-E00/NOPB; each drives one WLED string with independent current sink. |
| Max Sink Current | 23 mA per channel - specified at TA = –30°C to +85°C; supports typical 3–6 series white LEDs per string. |
| Switching Frequency | 625 kHz - pre-programmed EPROM setting; balances EMI, efficiency, and component size for tablet form factor. |
| Dimming Interface | PWM-only (no I²C) - EN/VDDIO serves as logic supply; SDA/SCL pins are functional but not enabled in this variant. |
| Fault Protection | LED open/short, UVLO, TSD (150°C), OCP, 6-level OVP - autonomous detection without host intervention; status reported via hardware flag. |
Pinout & Package
LP8556SQE-E00/NOPB uses a 24-pin, 0.5-mm pitch WQFN package (4.00 mm × 4.00 mm nominal body size) with exposed thermal pad (DAP) connected to GND for enhanced thermal dissipation (RθJA = 35.0°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| EN / VDDIO | Dual-purpose power and enable | Supplies 1.62–3.6 V to PWM/SDA/SCL inputs; must be driven by ≥1 mA capable logic gate; asserts chip enable when high. |
| PWM | Digital dimming input | Accepts 75 Hz–25 kHz PWM signal; controls LED brightness with 10-bit resolution; tied to GND if unused. |
| VDD | Main power input | 2.7–20 V supply feeding internal LDO; powers core logic, boost controller, and current sinks. |
| VBOOST | Boost converter output | Regulated high-voltage rail (16–34.5 V); monitored for OVP and feedback; requires low-ESR capacitor placement adjacent to pin. |
| SW | Power switch node | Drain of integrated 0.19-Ω MOSFET; connects to boost inductor; slew rate programmable (1.9–7.5 V/ns) for EMI control. |
| LED1–LED5 | Current sink outputs | Five dedicated analog current sinks (23 mA max); each drives one WLED string cathode; floating if unused. |
| ISET | Current reference input | Connects RISET resistor to GND to set nominal sink current; disabled (floating) when ISET_EN = 0 in EPROM. |
| FSET | Frequency programming | Accepts RFSET resistor to GND for frequency selection; left floating since BOOST_FREQ is EPROM-configured to 625 kHz. |
| VLDO | LDO output | 3.0 V ±50 mV regulated output; powers internal circuitry; requires 10 µF CVLDO capacitor to GND. |
| GND, GND_SW, DAP | Ground terminals | Separate analog/digital/power grounds; GND_SW ties to MOSFET source; DAP is thermal pad (GND-connected). |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive output voltage control | Maintains VBOOST just above LED string VF sum, reducing power loss up to 30% vs. fixed-output boost in dynamic brightness conditions. |
| Phase-shifted PWM dimming | Staggers turn-on timing across LED channels to suppress acoustic noise and allow smaller COUT (≤4.7 µF typical). |
| Programmable slew rate | Configurable SW edge rates (1.9–7.5 V/ns) lower peak EMI amplitude without sacrificing efficiency or transient response. |
| 6-level overvoltage protection | OVP threshold selectable from 17.9 V to 44.2 V in discrete steps; prevents damage during open-circuit or over-string-failure events. |
| Integrated 0.19-Ω MOSFET | Eliminates external high-side switch; reduces BOM count and layout area while maintaining >90% peak efficiency at 23 mA × 5 channels. |
Applications
| Tablet LCD Backlighting | Industrial HMI Display |
|---|---|
Use Scenario: 10.1-inch IPS LCD panel with 5 parallel WLED strings (6 LEDs/string) in a battery-powered medical tablet. IC Role / Device Role / Timing Role: LP8556SQE-E00/NOPB acts as primary LED driver, regulating current per string and adapting VBOOST in real time to maintain uniform luminance across 0–100% brightness. Use Value: Adaptive headroom cuts average power by 22% versus fixed 36 V boost; phase-shifted PWM eliminates coil whine during UI navigation. |
Use Scenario: Ruggedized 7-inch capacitive touchscreen used in factory automation with ambient temperature range –20°C to +70°C. IC Role / Device Role / Timing Role: LP8556SQE-E00/NOPB provides fault-resilient backlight drive with automatic LED open/short detection and thermal shutdown at 150°C junction. Use Value: Six-level OVP prevents overvoltage stress during cable disconnect events; GND_SW separation improves noise immunity in electrically noisy plant environments. |
| POS Terminal Display | Automotive Infotainment Panel |
Use Scenario: Compact retail point-of-sale terminal with dual-zone backlight (top/bottom) powered from 12 V DC input. IC Role / Device Role / Timing Role: LP8556SQE-E00/NOPB drives five strings in split configuration (3+2), using PWM input from microcontroller for zone-specific dimming. Use Value: 10-bit PWM resolution enables smooth 1024-step dimming; 2.7 V minimum VDD supports brownout operation during vehicle cranking. |
Use Scenario: 12.3-inch digital instrument cluster with AEC-Q200-compliant design requirements and extended temperature validation. IC Role / Device Role / Timing Role: LP8556SQE-E00/NOPB supplies regulated current to high-brightness WLED strings while reporting faults (OCP, TSD) to MCU via dedicated FLAG pin (not shown in pin table but documented in datasheet). Use Value: 35.0°C/W RθJA enables operation at 85°C ambient with <125°C junction; UVLO hysteresis (50–100 mV) prevents cycling during battery transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED backlight driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LP8556TME-E02/NOPB | DSBGA-20 package; supports both PWM and I²C interfaces; 6-channel, 25 mA/channel; VBOOST range 16–30 V. | Requires PCB redesign for smaller 2.4 × 1.74 mm footprint; enables firmware-based brightness tuning and diagnostics via I²C. | Select when system includes I²C master and board space is constrained; not drop-in compatible due to package and pinout differences. |
| TPS61165DRVR | Single-channel boost LED driver; 1.8 A switch current; 2.7–6 V input; 27 V max output; no integrated current sinks beyond one channel. | Requires five separate ICs for 5-channel operation; lacks adaptive VBOOST, phase-shifted PWM, and multi-level OVP. | Choose only for ultra-low-cost single-string applications; not suitable as functional replacement for LP8556SQE-E00/NOPB's integrated 5-channel architecture. |
Compared with LP8556TME-E02/NOPB, LP8556SQE-E00/NOPB trades I²C flexibility and higher per-channel current for simplified PWM-only control and WQFN thermal performance. Against TPS61165DRVR, it delivers five-channel integration, adaptive voltage, and comprehensive fault coverage-reducing total solution size by >60% and eliminating inter-IC synchronization complexity.
Availability
LP8556SQE-E00/NOPB is available at Aetrix Electronics and suitable for tablet backlighting, industrial HMI displays, and POS terminal designs requiring stable component supply, long-term production continuity, and automotive-grade reliability validation.
Supply support for LP8556SQE-E00/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 analog and embedded processing chips for industrial, automotive, and consumer applications with emphasis on power efficiency and system integration.
The LP8556 product line targets high-efficiency LED backlight drivers for portable displays, emphasizing adaptive voltage control, multi-channel precision current regulation, and robust fault handling in space-constrained environments.
FAQ
What is the configured LED channel count and maximum current per channel for LP8556SQE-E00/NOPB?
The LP8556SQE-E00/NOPB is factory-configured for 5-channel operation with a maximum sink current of 23 mA per channel across the full operating temperature range (–30°C to +85°C). This configuration is fixed in EPROM and cannot be altered post-manufacture. The device does not support 6-channel mode in this variant, unlike LP8556TME-E02/NOPB.
Does LP8556SQE-E00/NOPB support I²C communication, and how is its interface mode determined?
No, LP8556SQE-E00/NOPB is configured as "PWM Only" per TI's Device Options table and does not enable I²C functionality-even though SDA and SCL pins are physically present on the WQFN package. The interface mode is hard-coded in EPROM at manufacture; SDA/SCL remain unconnected internally and must be left floating or pulled low per layout guidelines.
What is the exact boost output voltage range programmed into LP8556SQE-E00/NOPB, and how is it set?
LP8556SQE-E00/NOPB is programmed with VBOOST_RANGE = 1 and VBOOST_MAX = 101, yielding a boost output voltage range of 16 V to 34.5 V. This range is stored in on-chip EPROM and cannot be modified externally; no resistor or register write alters it. The adaptive control algorithm dynamically adjusts VBOOST within this window based on LED string forward voltage.
How does the thermal performance of LP8556SQE-E00/NOPB compare between WQFN and DSBGA packages?
LP8556SQE-E00/NOPB uses the 24-pin WQFN package, which has RθJA = 35.0°C/W-nearly half that of the DSBGA variant (66.2°C/W). This allows higher continuous power dissipation at ambient temperatures up to +85°C. The WQFN's exposed thermal pad (DAP) must be soldered to a solid GND plane to achieve rated thermal resistance.
Can LP8556SQE-E00/NOPB drive more than 5 LED strings, and what happens to unused LEDx pins?
No, LP8556SQE-E00/NOPB is strictly a 5-channel device; LED6 pin is not functional and must be left floating. Unused LED1–LED5 pins may also be left unconnected with no impact on operation. Driving additional strings would require a second IC or a different variant such as LP8556TME-E02/NOPB (6-channel), which has incompatible EPROM settings and pin mapping.
LP8556SQE-E00/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:
- 5
- Voltage - Supply (Min):
- 2.7V
- Voltage - Supply (Max):
- 20V
- Voltage - Output:
- 7V ~ 43V
- Current - Output / Channel:
- 50mA
- Frequency:
- 312kHz, 625kHz, 1250kHz
- Dimming:
- PWM
- Applications:
- Backlight
- Operating Temperature:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-WQFN (4x4)
LP8556SQE-E00/NOPB FAQ
1.How can I place an order for LP8556SQE-E00/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP8556SQE-E00/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 LP8556SQE-E00/NOPB reliable?
The price and inventory of LP8556SQE-E00/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP8556SQE-E00/NOPB is usually 5 days.
3.What payment methods are accepted for LP8556SQE-E00/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP8556SQE-E00/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP8556SQE-E00/NOPB?
LP8556SQE-E00/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP8556SQE-E00/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 LP8556SQE-E00/NOPB?
For technical support, including LP8556SQE-E00/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP8556SQE-E00/NOPB requirements.
6.How does Aetrix verify that LP8556SQE-E00/NOPB is sourced from the original manufacturer or authorized distributors?
All LP8556SQE-E00/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 LP8556SQE-E00/NOPB meets industry standards.
7.What is the process for return or replacement of LP8556SQE-E00/NOPB?
All LP8556SQE-E00/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP8556SQE-E00/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 LP8556SQE-E00/NOPB part is unused and in its original packaging.
Return procedure for LP8556SQE-E00/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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