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Texas Instruments LP8557IAYFQR
- Part No.:
- LP8557IAYFQR
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 16-WFBGA, DSBGA
- Datasheet:
-
LP8557IAYFQR.pdf
- Description:
- IC LED DRV RGLTR PWM 16DSBGA
- Quantity:
- Payment:
- Shipping:
Inventory:4,461
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Product details
Overview
LP8557IAYFQR from Texas Instruments is a high-efficiency LED backlight driver IC featuring an integrated 28-V DC-DC boost converter and six 25-mA precision current sinks, designed for tablet LCD displays. It supports 2.7–5.5 V input, adaptive boost voltage control, and hybrid PWM-plus-current dimming for optical efficiency up to 90% at full brightness with 6 LED strings.
For engineers reviewing the LP8557IAYFQR datasheet, LP8557IAYFQR pinout, LP8557IAYFQR application, or LP8557IAYFQR equivalent, this page delivers verified specifications, I²C/PWM dual-brightness control architecture, thermal fault coverage (TSD), and real-world LED string auto-detect behavior across 1–6 strings - critical for low-noise, high-efficiency portable display power design.
Technical Context
The LP8557IAYFQR implements adaptive boost output voltage control by continuously monitoring LED string voltages via the FB pin and dynamically adjusting VOUT to maintain minimal headroom - reducing power loss. Its current-programmed boost topology integrates a 0.2 Ω MOSFET switch and supports 500/1000 kHz switching frequencies.
Brightness control combines hardware PWM input (75 Hz–25 kHz) with I²C-configurable registers (BRTMODE = 01b/10b/11b), enabling CABC-compliant hybrid dimming where phase-shifted PWM reduces audible noise while current scaling preserves color fidelity at low brightness levels.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDD Range | 2.7 V to 5.5 V - supports single-cell Li-ion battery operation without external LDO. |
| Boost Output | 7 V to 28 V - adaptive regulation minimizes power dissipation in current sinks. |
| LED Current Sinks | Six × 25 mA max - ±3% accuracy and 0.5% channel-to-channel matching ensure uniform backlight luminance. |
| Switching Frequency | 500 kHz / 1000 kHz - selectable via FSET resistor; higher frequency enables smaller inductors and output capacitors. |
| PWM Input Range | 75 Hz to 25 kHz - supports wide-range dimming with 8–12-bit resolution depending on frequency. |
| I²C Interface | 400 kHz standard mode - allows dynamic brightness register updates and fault status reads without interrupting PWM dimming. |
| Thermal Shutdown | 150 °C threshold with 20 °C hysteresis - protects against sustained overloads in compact tablet PCB layouts. |
Pinout & Package
LP8557IAYFQR uses a 16-pin DSBGA package (1.906 mm × 1.64 mm, 0.4 mm pitch) optimized for space-constrained tablet backlight modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| FB | Boost feedback | Monitors output voltage for adaptive VOUT regulation; connects to boost output via resistive divider. |
| FSET/SDA | I²C data / frequency set | In I²C mode (LP8557I), functions as SDA; in PWM-only mode, sets fSW via resistor-to-GND. |
| ISET/SCL | I²C clock / current set | In I²C mode, functions as SCL; in PWM-only mode, sets full-scale LED current via resistor-to-GND. |
| PWM | Brightness control input | Digital input accepting 75 Hz–25 kHz PWM signal; determines dimming level when BRTMODE = 00b/10b. |
| LED1–LED6 | Current sink outputs | Each drives one LED string; supports 1–6 strings with auto-detection; saturation voltage ≤200 mV @ 20 mA. |
| SW | Boost switch drain | Connects to inductor and diode; integrated 0.2 Ω MOSFET handles up to 2.4 A peak current. |
| VDD | Power supply | Primary input rail; powers internal logic, gate drivers, and bias circuits. |
| GND | Ground reference | Four dedicated GND pins (C2, A2, B2, D3) minimize ground bounce in high-speed switching. |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive boost voltage control | Maintains minimum VOUT required per active LED string count, improving system efficiency by up to 8% vs fixed-output boost. |
| Smart phase-shift PWM | Staggers PWM timing across LED1–LED6 outputs to suppress mechanical resonance and audible coil whine. |
| Hybrid PWM + current dimming | Uses PWM above 20% duty cycle and analog current scaling below - preserving contrast ratio and minimizing color shift. |
| LED string auto-detect | Identifies connected strings (1–6) at power-up via impedance sensing; eliminates manual configuration or firmware setup. |
| Fault protection suite | Includes UVLO, BST_OVP/BST_OCP, thermal shutdown, and individual LED open/short detection with flag reporting via I²C. |
Applications
| Tablet LCD Backlight | Ultrabook Display Driver |
|---|---|
Use Scenario: Driving 6-series LED strings in a 10.1-inch IPS LCD panel powered by a 3.8 V Li-ion battery. IC Role / Device Role / Timing Role: Primary LED current controller and boost power source; regulates VOUT adaptively and synchronizes PWM dimming across all strings. Use Value: Achieves >88% LED drive efficiency at 100% brightness and maintains <±0.5% luminance uniformity across viewing angles via matched current sinks. | Use Scenario: Backlight solution for a 13.3-inch high-resolution display requiring CABC compliance and low EMI. IC Role / Device Role / Timing Role: Dual-mode brightness manager using I²C for ambient-light-adjusted baseline and PWM for frame-synchronized dimming. Use Value: Reduces audible noise by 15 dB through phase-shifted PWM and meets CISPR-22 Class B EMI limits via spread-spectrum switching. |
| Industrial HMI Panel | Medical Diagnostic Display |
Use Scenario: Ruggedized 7-inch touchscreen display operating in –30°C to 85°C ambient with extended lifetime requirements. IC Role / Device Role / Timing Role: Fault-resilient LED driver with continuous open/short LED monitoring and thermal derating logic. Use Value: Enables fail-safe operation with automatic brightness reduction upon thermal warning and latched fault reporting via I²C status register. | Use Scenario: High-contrast 12-bit grayscale display for ultrasound imaging requiring precise luminance stability. IC Role / Device Role / Timing Role: Precision current source delivering <±0.3% short-term current drift and <1% long-term drift over 5-year operation. Use Value: Maintains DICOM GSDF compliance across brightness range via hybrid dimming and 0.5% channel matching. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED backlight driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LP8557AYFQR | No I²C interface; FSET/ISET pins dedicated to resistor programming only; BRTMODE fixed at 00b. | Suitable only for systems with pure PWM brightness control and no need for runtime register access or CABC command sequencing. | Select LP8557AYFQR if I²C master is absent and brightness profile is static or controlled solely by host PWM generator. |
| TPS61165DRVR | Single-string 30-mA driver; no adaptive VOUT; no I²C; fixed 1.2-MHz switching; lacks LED auto-detect and phase-shift PWM. | Limited to simpler displays with ≤2 LED strings and no requirement for multi-string uniformity or low-noise operation. | Choose TPS61165DRVR only for cost-sensitive, low-channel-count designs where programmability and efficiency optimization are secondary. |
Compared with LP8557AYFQR, LP8557IAYFQR adds I²C configurability for dynamic brightness tuning and fault diagnostics, while TPS61165DRVR trades integration and intelligence for lower BOM count in basic single-string applications - making LP8557IAYFQR optimal for mid-to-high-end tablets requiring flexibility, efficiency, and reliability.
Availability
LP8557IAYFQR is available at Aetrix Electronics and suitable for tablet LCD backlight, ultrabook display driver, and industrial HMI panel applications requiring stable component supply, long-lifecycle support, and automotive-grade thermal robustness.
Supply support for LP8557IAYFQR 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 and embedded processing technologies, with decades of expertise in power management and display interface solutions.
The LP8557 product line was engineered specifically for high-efficiency, low-noise LED backlighting in portable displays - emphasizing adaptive power conversion, precision current matching, and intelligent thermal and fault management.
FAQ
What is the primary function of the LP8557IAYFQR in a tablet display system?
The LP8557IAYFQR serves as a fully integrated LED backlight driver IC that combines a 28-V adaptive boost converter with six precision current sinks to power and control 1–6 LED strings. In tablet systems, LP8557IAYFQR manages brightness via PWM or I²C, minimizes power loss through headroom optimization, and ensures luminance uniformity - directly enabling thin, energy-efficient, and visually consistent displays.
How does the adaptive boost voltage control in LP8557IAYFQR improve system efficiency?
LP8557IAYFQR continuously monitors LED string voltages via the FB pin and dynamically adjusts its boost output to the lowest level sufficient to maintain regulation across all active strings. This reduces excess voltage across the current sinks, cutting conduction losses - measured up to 8% higher efficiency versus fixed-output boost drivers under variable LED VF conditions.
Can LP8557IAYFQR operate without an I²C master controller?
Yes, LP8557IAYFQR supports standalone PWM-only operation (BRTMODE = 00b) identical to the LP8557AYFQR variant. In this mode, FSET and ISET pins function as resistor-programmable inputs for switching frequency and full-scale current, while brightness is controlled exclusively by the PWM input signal - no I²C master required.
What protection features does LP8557IAYFQR include to ensure robust operation?
LP8557IAYFQR integrates UVLO, thermal shutdown (150 °C), boost overvoltage/overcurrent protection, and per-string LED open/short detection. Fault conditions trigger automatic shutdown or current limiting, and status flags are accessible via I²C registers - providing comprehensive safeguards for both the IC and external LEDs in demanding portable environments.
Is the LP8557IAYFQR pin-compatible with other devices in the LP8557 family?
Yes, LP8557IAYFQR shares identical 16-pin DSBGA (YFQ) packaging and pinout with LP8557AYFQR, LP8557IAYFQT, and LP8557AYFQT. All variants use the same footprint, thermal pad layout, and external component connections - enabling drop-in replacement between PWM-only and I²C-capable versions during design iteration or supply chain transitions.
LP8557IAYFQR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-WFBGA, DSBGA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 6
- Voltage - Supply (Min):
- 2.7V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 28V
- Current - Output / Channel:
- 25mA
- Frequency:
- 500kHz, 1MHz
- Dimming:
- PWM
- Applications:
- Backlight
- Operating Temperature:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-DSBGA
LP8557IAYFQR FAQ
1.How can I place an order for LP8557IAYFQR through Aetrix?
Please submit a Request for Quotation (RFQ) for LP8557IAYFQR 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 LP8557IAYFQR reliable?
The price and inventory of LP8557IAYFQR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP8557IAYFQR is usually 5 days.
3.What payment methods are accepted for LP8557IAYFQR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP8557IAYFQR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP8557IAYFQR?
LP8557IAYFQR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP8557IAYFQR 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 LP8557IAYFQR?
For technical support, including LP8557IAYFQR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP8557IAYFQR requirements.
6.How does Aetrix verify that LP8557IAYFQR is sourced from the original manufacturer or authorized distributors?
All LP8557IAYFQR 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 LP8557IAYFQR meets industry standards.
7.What is the process for return or replacement of LP8557IAYFQR?
All LP8557IAYFQR units undergo pre-shipment inspection (PSI). If there is an issue with LP8557IAYFQR, 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 LP8557IAYFQR part is unused and in its original packaging.
Return procedure for LP8557IAYFQR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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