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Texas Instruments LP55281RL/NOPB
- Part No.:
- LP55281RL/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 36-WFBGA, DSBGA
- Datasheet:
-
LP55281RL/NOPB.pdf
- Description:
- IC LED DRV RGLTR I2C 36DSBGA
- Quantity:
- Payment:
- Shipping:
Inventory:1,969
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Product details
Overview
LP55281RL/NOPB from Texas Instruments is a 12-channel RGB/white LED driver IC with integrated magnetic boost DC-DC converter, SPI/I²C interface, and audio-synchronized ALED output. It drives four independent RGB LED sets (R1–R4, G1–G4, B1–B4) plus one dedicated fun-light LED (ALED), supports 4–5.3 V boost output, 300–400 mA max load, and 9.92–39.68 kHz programmable PWM frequency for handheld lighting applications.
For engineers reviewing the LP55281RL/NOPB datasheet, LP55281RL/NOPB pinout, LP55281RL/NOPB application, or LP55281RL/NOPB equivalent, key selection criteria include its dual-interface flexibility (SPI or I²C), on-chip audio sync with stereo ASE1/ASE2 inputs, 8-bit boost voltage control, LED connectivity test capability, and DSBGA-36 package optimized for space-constrained mobile devices.
Technical Context
The LP55281RL/NOPB integrates a current-programmed mode (CPM) magnetic boost converter with selectable 1/1.67/2 MHz switching frequency (via RT resistor and FRQ_SEL[2:0]), overvoltage/overcurrent/feedback-break protection, and active load control to suppress pulse skipping. Its RGB drivers use a shared external RRGB bias resistor and per-channel 6-bit PWM + 2-bit coarse current scaling (0.25×–1.00× IMAX) for precise color mixing.
Audio synchronization is implemented digitally: dual ASE1/ASE2 inputs (0–1.6 VPP) feed an ADC, AGC, peak detector, and threshold-controlled ALED brightness engine with four refresh rate options; the ALED output delivers up to 13.2 mA with ±10% tolerance and supports manual override via register control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Boost Output Voltage | Programmable 4.0–5.3 V in 9 steps via 8-bit register; enables stable LED drive from 3–4.5 V Li-ion battery. |
| Max Boost Load Current | 300 mA at 5 V output or 400 mA at 4 V output; defines total LED current budget for RGB + ALED channels. |
| RGB PWM Frequency | Selectable 9.92 / 19.84 / 39.68 kHz; eliminates audible noise while enabling high-fidelity color transitions. |
| ALED Sync Inputs | Stereo ASE1 & ASE2 (10–15 kΩ input impedance, 0–1600 mVPP range); allows real-time light response to music or voice. |
| Interface Options | SPI (up to 13 MHz) or I²C (400 kHz standard mode); IF_SEL pin selects protocol; two I²C addresses support multi-device bus sharing. |
| Package | 36-pin DSBGA (2.982 mm × 2.982 mm); ultra-compact footprint with bottom-side ball layout for mobile PCB area optimization. |
| Thermal Resistance | RθJA = 48.9°C/W (YPG) or 49.1°C/W (YZR); enables operation up to +125°C junction temperature with minimal heatsinking. |
Pinout & Package
LP55281RL/NOPB uses a 36-pin DSBGA (Die Size Ball Grid Array) package with 0.4 mm pitch, measuring 2.982 mm × 2.982 mm. The package features bottom-side solder balls and requires controlled thermal pad design per TI layout guidelines.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD1, VDD2, VDDIO, VDDA | Power supply inputs | VDD1/VDD2: main logic supplies (2.7–5.5 V); VDDIO: I/O buffer supply (1.65–VDD1); VDDA: internal LDO output (2.8 V ±3%) for analog blocks. |
| R1–R4, G1–G4, B1–B4 | RGB LED sink outputs | 12 dedicated current-sink channels; each pair (e.g., R1/G1/B1) forms one RGB set; max 40 mA per channel with RRGB = 8.2 kΩ. |
| ALED | Audio-sync LED output | Dedicated current sink (13.2 mA ±10%) synchronized to ASE1/ASE2 audio inputs; supports manual PWM override. |
| ASE1, ASE2 | Analog audio inputs | Stereo analog inputs (0–1.6 VPP) with 10–15 kΩ impedance; internally mixed and processed for ALED brightness modulation. |
| SCK/SCL, SI/A0, SS/SDA, SO | Serial interface pins | Configurable for SPI (SCK/SI/SS/SO) or I²C (SCL/SDA/A0); A0 selects second I²C address; IF_SEL = 1 enables SPI mode. |
| SW, FB, IRT, RRT | Boost converter controls | SW: power switch output; FB: feedback node for output voltage regulation; IRT/RRT: timing resistors setting oscillator frequency (82 kΩ → 2 MHz default). |
| NRST | Asynchronous reset | Active-low reset input (VIH ≥1.2 V, VIL ≤0.5 V); initiates hardware reset of all registers and state machines. |
| GND, GNDA, GND_RGB1, GND_RGB2, GND_SW | Ground terminals | Dedicated ground paths isolate analog (GNDA), RGB current sinks (GND_RGB1/2), boost switch (GND_SW), and digital (GND) domains to minimize noise coupling. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated magnetic boost converter | Eliminates need for external inductor driver; delivers 4–5.3 V at up to 400 mA with 89–91% efficiency at 100–300 mA loads. |
| Per-RGB-set PWM + coarse current control | Each RGB set (e.g., R1/G1/B1) has independent 6-bit PWM (63-step resolution) and 2-bit coarse scaling (0.25×–1.00× IMAX) for fine-grained color tuning. |
| Hardware LED connectivity test | Serial-interface-accessible diagnostic mode verifies open/short faults on all 13 outputs (R1–B4, ALED) without MCU firmware involvement. |
| Dual-mode audio synchronization | Supports both manual gain (GAIN_SEL[2:0]) and automatic gain control (EN_AGC) for robust ALED response across varying audio source levels. |
| Flexible dual-protocol interface | SPI or I²C selection via IF_SEL pin; two I²C addresses allow daisy-chaining multiple LP55281 devices on same bus for expanded LED arrays. |
Applications
| Smartphone Status Lighting | Wearable Fitness Tracker UI |
|---|---|
Use Scenario: RGB LEDs illuminate status indicators (charging, notifications, battery level) on smartphone bezels or under-glass zones. IC Role / Device Role / Timing Role: LP55281RL/NOPB acts as primary LED driver, managing 12-channel color mixing, boost voltage generation, and low-power standby sequencing. Use Value: Integrated boost enables consistent brightness across battery discharge (3–4.5 V), while 39.68 kHz PWM prevents visible flicker and EMI interference with cellular radios. | Use Scenario: Circular RGB ring around wearable display pulses in rhythm with heart rate or step count, using ambient audio cues. IC Role / Device Role / Timing Role: LP55281RL/NOPB serves as audio-reactive lighting controller, digitizing microphone input via ASE1/ASE2 and modulating ALED + RGB sets in real time. Use Value: On-chip AGC and peak detection eliminate external signal conditioning; stereo input support allows left/right channel differentiation for immersive visual feedback. |
| Portable Media Player Visualizer | Tablet Camera Flash Assist |
Use Scenario: MP3 player front panel displays dynamic light patterns synced to music genre, tempo, or bass intensity. IC Role / Device Role / Timing Role: LP55281RL/NOPB functions as audio-synchronized LED engine, converting analog audio into proportional ALED brightness and RGB hue shifts. Use Value: Four programmable ALED refresh rates (controlled by SPEED_CTRL[1:0]) let designers match visual persistence to musical dynamics-slow for ambient, fast for percussive tracks. | Use Scenario: Tablet rear camera uses RGB LEDs as tunable flash (white balance adjustment) or video light with smooth dimming. IC Role / Device Role / Timing Role: LP55281RL/NOPB operates as precision current sink, driving R/G/B channels independently to generate calibrated white light or color-corrected illumination. Use Value: Per-channel 6-bit PWM + 2-bit coarse scaling enables <1% current matching error between R/G/B, critical for accurate color rendering in photography applications. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar RGB LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LP5562RSBT | 6-channel RGB driver (R1–R3, G1–G3, B1–B3); no ALED output; integrated 1.8-V LDO; 24-pin WQFN package. | Lacks audio sync and fun-light LED functionality; suited for simpler UI lighting where stereo audio reaction is unnecessary. | Select LP5562RSBT when board space is constrained and only three RGB sets are needed without audio features. |
| LP55231YFQR | 9-channel RGB driver (R1–R3, G1–G3, B1–B3); includes ALED output; supports I²C only; 24-pin DSBGA package. | Fewer RGB channels (9 vs. 12); identical ALED sync architecture but no SPI interface option; smaller package footprint. | Choose LP55231YFQR for cost-sensitive designs requiring audio sync and compact size, accepting reduced channel count. |
Compared with LP5562RSBT and LP55231YFQR, the LP55281RL/NOPB uniquely combines 12 RGB channels, stereo audio sync, SPI/I²C dual interface, and programmable boost voltage-making it optimal for premium mobile devices demanding full-color lighting versatility and real-time audio responsiveness.
Availability
LP55281RL/NOPB is available at Aetrix Electronics and suitable for smartphone status lighting, wearable fitness tracker UI, portable media player visualizers, and tablet camera flash assist applications requiring stable component supply and long-term production continuity.
Supply support for LP55281RL/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 energy-efficient electronics.
The LP55281RL/NOPB belongs to TI's LP55xx family of highly integrated LED drivers designed specifically for mobile and portable consumer devices requiring compact, low-power, and feature-rich lighting solutions.
FAQ
What is the maximum output current capability of the LP55281RL/NOPB boost converter?
The LP55281RL/NOPB boost converter delivers up to 300 mA at 5 V output or 400 mA at 4 V output, as specified in the Recommended Operating Conditions table. This current budget supports simultaneous operation of all 12 RGB channels and the ALED output under typical handheld device power constraints. The actual achievable current depends on input voltage, inductor value (4.7 µH recommended), and thermal conditions-TI specifies 48.9°C/W junction-to-ambient thermal resistance for derating calculations.
How does the LP55281RL/NOPB implement audio synchronization, and what inputs does it require?
The LP55281RL/NOPB implements audio synchronization through two dedicated analog inputs-ASE1 and ASE2-with 10–15 kΩ input impedance and 0–1600 mVPP operating range. These stereo inputs feed an internal ADC, AGC, peak detector, and digital DC-remover (–3 dB at 500 Hz), enabling real-time ALED brightness modulation based on audio amplitude. The LP55281RL/NOPB processes both channels simultaneously and mixes them for unified light response, supporting manual gain control or automatic adaptation to varying source levels.
Can the LP55281RL/NOPB drive LEDs from an external power supply instead of its internal boost converter?
Yes, the LP55281RL/NOPB supports external supply operation for its RGB outputs. While the boost converter provides regulated 4–5.3 V for driving LEDs directly from a Li-ion battery, the R1–R4, G1–G4, and B1–B4 sink outputs can alternatively be powered from an external voltage rail applied to VDD1/VDD2. This configuration bypasses the boost stage and reduces power loss when a suitable system supply (e.g., 3.3 V or 5 V) is already available, preserving battery life in always-on lighting scenarios.
What is the purpose of the IF_SEL pin on the LP55281RL/NOPB, and how should it be configured?
IF_SEL is a logic input that selects the serial communication protocol: when pulled high (IF_SEL = 1), the LP55281RL/NOPB operates in SPI mode using SCK/SI/SS/SO pins; when low (IF_SEL = 0), it defaults to I²C mode using SCK/SCL and SS/SDA pins. This pin enables hardware-selectable interface flexibility without firmware reconfiguration. TI recommends connecting IF_SEL to VDDIO or GND via a pull-up/down resistor-no floating connections-to ensure deterministic startup behavior and avoid communication initialization failures.
Does the LP55281RL/NOPB support LED open/short diagnostics, and how is it accessed?
Yes, the LP55281RL/NOPB includes built-in LED connectivity test functionality accessible via its serial interface. By writing to specific diagnostic registers, the device performs open-circuit and short-circuit detection on all 13 outputs (R1–B4 and ALED) using internal current sources and comparators. Results are reported back through status registers, enabling automated factory testing or runtime fault monitoring without external test equipment. This feature is documented in Section 7.3.4 of the LP55281RL/NOPB datasheet and requires no additional components beyond the standard application circuit.
LP55281RL/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 36-WFBGA, DSBGA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 12
- Voltage - Supply (Min):
- 3V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 4V ~ 5.3V
- Current - Output / Channel:
- 40mA
- Frequency:
- 2MHz
- Dimming:
- I2C, SPI
- Applications:
- Backlight
- Operating Temperature:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 36-DSBGA (3.5x3.24)
LP55281RL/NOPB FAQ
1.How can I place an order for LP55281RL/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP55281RL/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 LP55281RL/NOPB reliable?
The price and inventory of LP55281RL/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP55281RL/NOPB is usually 5 days.
3.What payment methods are accepted for LP55281RL/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP55281RL/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP55281RL/NOPB?
LP55281RL/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP55281RL/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 LP55281RL/NOPB?
For technical support, including LP55281RL/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP55281RL/NOPB requirements.
6.How does Aetrix verify that LP55281RL/NOPB is sourced from the original manufacturer or authorized distributors?
All LP55281RL/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 LP55281RL/NOPB meets industry standards.
7.What is the process for return or replacement of LP55281RL/NOPB?
All LP55281RL/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP55281RL/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 LP55281RL/NOPB part is unused and in its original packaging.
Return procedure for LP55281RL/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LP55281RL/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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