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Texas Instruments LP5521YQX/NOPB
- Part No.:
- LP5521YQX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-VFQFN Exposed Pad
- Datasheet:
-
LP5521YQX/NOPB.pdf
- Description:
- IC LED DRVR RGLTR I2C 24WQFN
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
LP5521YQX/NOPB from Texas Instruments is a three-channel RGB LED driver IC with integrated adaptive charge pump (1×/1.5×), 8-bit programmable current sources (0–25.5 mA per channel), autonomous program execution engine, and I²C-compatible interface. It delivers precise lighting effects for mobile indicator and backlight applications across full Li-ion battery range (2.7 V to 5.5 V) while maintaining ≤50 mV saturation voltage and ±1% current matching.
For engineers reviewing the LP5521YQX/NOPB datasheet, LP5521YQX/NOPB pinout, LP5521YQX/NOPB application, or LP5521YQX/NOPB equivalent, key selection criteria include autonomous sequence execution capability, dual-mode charge pump gain control, 32-kHz clock synchronization support, interrupt-triggered host notification, and four I²C address options enabling up to four devices on one bus.
Technical Context
The LP5521YQX/NOPB integrates a pre-regulated switched-capacitor charge pump with automatic 1×/1.5× gain selection based on real-time LED forward voltage monitoring and digital filtering to suppress false triggers from supply transients. Its three independent constant-current outputs feature 8-bit current setting (100 µA resolution) and 8-bit PWM control with selectable high-frequency (558 Hz) or low-frequency (256 Hz) modes.
It embeds three program execution engines with SRAM-based instruction memory, enabling self-contained lighting sequences without continuous host intervention. The device supports synchronized multi-device operation via TRIG I/O and CLK_32K input, while GPO and open-drain INT pins provide flexible system-level control and status signaling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| LED Channels | Three independent R/G/B constant-current outputs with 0–25.5 mA programmable range |
| Charge Pump Gain | Auto-selectable 1× (bypass) or 1.5× (boost to ~4.5 V); enables full Li-ion voltage range operation |
| Current Matching | ±1% typical between R/G/B channels at 17.5 mA - ensures uniform color balance |
| Saturation Voltage | 50 mV typical at 17.5 mA - minimizes power loss and thermal rise in LED drivers |
| I²C Address Options | Four pin-selectable addresses (via ADDR_SEL0/ADDR_SEL1) - supports up to four devices on one bus |
| Supply Current (Standby) | 0.2 µA typical with EN = 0 - enables ultra-low-power system sleep states |
| PWM Frequency | 256 Hz (32-kHz clock sourced) or 558 Hz (internal oscillator) - selectable for flicker-free or low-noise operation |
Pinout & Package
LP5521YQX/NOPB uses a 24-pin WQFN package (5.00 mm × 4.00 mm nominal body size) with exposed thermal pad. Pin functions are validated per TI SNVS441I datasheet Rev. I (November 2016).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1–2, 23–24 | CFLY2P / CFLY1P / CFLY2N / CFLY1N | Charge pump flying capacitor terminals - require 0.47 µF X5R/X7R MLCCs for stable 1.5× boost operation |
| 3 | VDD | Main power supply input (2.7–5.5 V) - powers logic, charge pump bias, and internal regulators |
| 4, 12 | GND | Dual ground connections - critical for noise immunity and thermal dissipation via exposed pad |
| 5 | CLK_32K | 32-kHz clock input - synchronizes PWM timing and enables low-power mode with external crystal or oscillator |
| 6 | INT | Open-drain interrupt output - signals end of autonomous LED sequence or fault condition to host MCU |
| 7 | TRIG | Configurable trigger I/O - initiates sequences or provides inter-device synchronization pulse |
| 13–15 | SDA / EN / SCL | I²C data, chip enable, and clock - support standard/fast-mode I²C (≤400 kHz) with 0.2–0.8×VDD logic thresholds |
| 16 | GPO | General-purpose output - push-pull capable (VDD–0.5 V high, 0.3 V low @ 3 mA) for auxiliary control |
| 17–19 | R / G / B | Constant-current LED sink outputs - each independently programmable (8-bit current + 8-bit PWM) |
| 20–21 | ADDR_SEL0 / ADDR_SEL1 | I²C address select inputs - set one of four device addresses (0x30–0x33) for multi-drop bus configuration |
| 22 | VOUT | Charge pump regulated output - supplies boosted voltage (~4.5 V in 1.5× mode) to G/B drivers and optionally R |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive charge pump gain control | Automatically switches between 1× and 1.5× based on real-time LED headroom monitoring - eliminates manual gain selection and improves efficiency across battery discharge cycle |
| Autonomous program execution | Three independent engines with SRAM-based instruction memory - runs preloaded lighting sequences without CPU involvement, reducing host processor load and system power |
| Flexible R-channel power routing | R output configurable to connect to VDD (battery) or VOUT (charge pump) - enables optimal efficiency for low-VF red LEDs while preserving automatic gain control for G/B |
| Low-EMI charge pump architecture | No inductor required; uses only four ceramic capacitors (CIN, COUT, CFLY1, CFLY2) - simplifies layout, reduces solution size, and minimizes conducted/radiated noise |
| Integrated protection | Soft-start, overcurrent, short-circuit, and thermal shutdown (150°C TJ) - ensures robust operation under fault conditions without external circuitry |
Applications
| Mobile Indicator Lighting | LCD Sub-Display Backlighting |
|---|---|
|
Use Scenario: Dynamic status indication on smartphones, wearables, and portable medical devices using RGB LED patterns. IC Role / Device Role / Timing Role: Autonomous LED driver executing stored lighting sequences; manages R/G/B current and PWM timing without host CPU polling. Use Value: Enables rich visual feedback (breathing, pulsing, color cycling) with <2 µA standby current and zero host intervention after initialization. |
Use Scenario: Power-efficient backlighting for small monochrome or segmented LCDs in handheld POS terminals and blood glucose meters. IC Role / Device Role / Timing Role: Constant-current source delivering precise brightness control via 8-bit PWM; charge pump maintains consistent output across 2.7–5.5 V battery range. Use Value: Eliminates need for external DC-DC converter or resistor-based current limiting - reduces BoM cost and PCB area by >30% versus discrete solutions. |
| Keypad RGB Backlighting | Electronic Access Control UI |
|
Use Scenario: Illuminated keypad or touch-sensitive overlay in security panels and industrial HMI where color-coded feedback is critical. IC Role / Device Role / Timing Role: Independent R/G/B current control with synchronized multi-device triggering via TRIG pin - enables coordinated illumination across multiple zones. Use Value: Achieves uniform color rendering (±1% current match) and flicker-free operation (256 Hz PWM) even during low-battery conditions. |
Use Scenario: Visual status indicators (e.g., door lock/unlock, access granted/denied) in smart locks and access readers requiring long battery life. IC Role / Device Role / Timing Role: Ultra-low-power LED driver with 0.2 µA shutdown current and autonomous sequence execution - extends coin-cell or Li-SOCl₂ battery life to >5 years. Use Value: Reduces average system current by >95% versus always-on GPIO-driven LEDs while supporting complex multi-color alerts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar RGB LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LP55231YFFR | Single-chip 6-channel variant with identical charge pump, memory architecture, and I²C interface; adds two extra LED channels and enhanced diagnostics. | Supports dual RGB modules or RGB+white configurations; requires larger 32-pin WQFN package (6 mm × 6 mm). | Select when expanding to >3 LED channels or needing built-in fault reporting - same firmware compatibility but higher pin count and cost. |
| TPS61165DRVR | Dedicated 3-channel white LED driver with fixed 1.5× charge pump, no program memory, and analog/digital dimming only - lacks autonomous execution and RGB current independence. | Optimized for white LED backlighting with simpler control; no RGB color mixing or pattern generation capability. | Select for cost-sensitive white-backlight designs where autonomous sequences and individual RGB control are unnecessary. |
Compared with LP5521YQX/NOPB, LP55231YFFR offers scalable channel count and diagnostics at the expense of footprint and complexity, while TPS61165DRVR provides lower-cost white-light driving without programmability or RGB flexibility - making LP5521YQX/NOPB the optimal choice for compact, autonomous RGB indicator systems.
Availability
LP5521YQX/NOPB is available at Aetrix Electronics and suitable for mobile indicator lighting, LCD sub-display backlighting, and keypad RGB backlighting requiring stable component supply, long-term lifecycle support, and automotive-grade reliability screening.
Supply support for LP5521YQX/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 precision LED drivers and low-power system solutions.
The LP5521YQX/NOPB belongs to TI's LP55xx family of autonomous LED drivers designed specifically for battery-powered mobile and portable electronics requiring efficient, programmable RGB lighting with minimal host processor overhead.
FAQ
What is the maximum LED current supported by the LP5521YQX/NOPB?
The LP5521YQX/NOPB supports up to 25.5 mA per channel (R, G, B) with 100 µA resolution via 8-bit current register control. This is confirmed in Section 6.7 of the SNVS441I datasheet, where IMAX is specified as 25.5 mA for all three outputs. The device maintains ≤50 mV saturation voltage at this level, ensuring minimal power loss and thermal stress in the LED driver stage of the LP5521YQX/NOPB.
Does the LP5521YQX/NOPB require external programming before autonomous operation?
Yes - the LP5521YQX/NOPB must be programmed via its I²C interface to load lighting sequences into its SRAM-based program memory before autonomous execution. TI provides a command compiler tool to generate compatible instruction sets. Once loaded and enabled, the LP5521YQX/NOPB executes sequences independently without further host interaction, entering power-save mode automatically when idle.
Can the LP5521YQX/NOPB drive LEDs directly from the battery without using the charge pump?
Yes - the R-channel output of the LP5521YQX/NOPB can be configured via register bit R_TO_BATT (address 08H) to connect directly to VDD instead of VOUT. This bypasses the charge pump for red LEDs with low forward voltage, improving efficiency. G and B channels remain tied to VOUT and retain automatic gain control - a feature unique to the LP5521YQX/NOPB among its family.
What is the purpose of the TRIG pin on the LP5521YQX/NOPB?
The TRIG pin on the LP5521YQX/NOPB serves as a bidirectional synchronization interface: it can initiate LED sequences on the local device or receive trigger pulses from other LP5521YQX/NOPB units to coordinate multi-device lighting effects. In hardware-triggered mode, a rising edge on TRIG starts execution of the currently loaded program - enabling tightly timed visual responses across distributed UI elements using the LP5521YQX/NOPB.
How does the LP5521YQX/NOPB manage thermal performance in compact layouts?
The LP5521YQX/NOPB uses a thermally enhanced 24-pin WQFN package with an exposed pad (RθJA = 38.4°C/W) and integrates thermal shutdown at 150°C (typical). Its adaptive charge pump minimizes power loss by selecting 1× gain when sufficient battery voltage exists, and its 50 mV saturation voltage reduces heat generation in the current-source transistors - critical for sustained operation in space-constrained mobile designs using the LP5521YQX/NOPB.
LP5521YQX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Switched Capacitor (Charge Pump)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 3
- Voltage - Supply (Min):
- 2.7V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 4.55V
- Current - Output / Channel:
- 25.5mA
- Frequency:
- 1.25MHz
- Dimming:
- I2C
- Applications:
- Backlight
- Operating Temperature:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-WQFN (5x4)
LP5521YQX/NOPB FAQ
1.How can I place an order for LP5521YQX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP5521YQX/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 LP5521YQX/NOPB reliable?
The price and inventory of LP5521YQX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP5521YQX/NOPB is usually 5 days.
3.What payment methods are accepted for LP5521YQX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP5521YQX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP5521YQX/NOPB?
LP5521YQX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP5521YQX/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 LP5521YQX/NOPB?
For technical support, including LP5521YQX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP5521YQX/NOPB requirements.
6.How does Aetrix verify that LP5521YQX/NOPB is sourced from the original manufacturer or authorized distributors?
All LP5521YQX/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 LP5521YQX/NOPB meets industry standards.
7.What is the process for return or replacement of LP5521YQX/NOPB?
All LP5521YQX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP5521YQX/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 LP5521YQX/NOPB part is unused and in its original packaging.
Return procedure for LP5521YQX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LP5521YQX/NOPB Tags
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HV9910CLG-G
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