Texas Instruments LP5868TMRKPR

Overview

LP5868TMRKPR from Texas Instruments is an 8 × 18 high-current LED matrix driver IC with 18 constant current sinks and 8 high-side PMOS scan switches, supporting up to 144 individually addressable LED dots. It delivers 100 mA per sink at VCC ≥ 3.3 V, ±5% device-to-device and channel-to-channel current accuracy, and supports both 8-bit/16-bit PWM (62.5 kHz / 125 kHz) and 8-bit analog dimming for RGB keyboard backlighting and smart appliance indicators.

For engineers reviewing the LP5868TMRKPR datasheet, LP5868TMRKPR pinout, LP5868TMRKPR application, or LP5868TMRKPR equivalent, key selection considerations include its VQFN-40 (RKP) package, dual I²C (1 MHz) / SPI (12 MHz) interface, extended temperature range (–55°C to +125°C), integrated open/short detection, and de-ghosting circuitry for high-fidelity matrix display control.

Technical Context

The LP5868TMRKPR implements a time-multiplexed 8-line scan architecture with programmable scan count (6–8 lines), phase-shifted PWM generation to balance transient power, and full SRAM-based frame buffer for minimized data traffic. Its analog dimming path uses three hierarchical controls: global 3-bit Maximum Current (MC), per-group 7-bit Color Current (CC), and per-dot 8-bit Dot Current (DC).

Digital interface selection is hardware-configured via IFS pin: low enables I²C (up to 1 MHz, Fast Mode Plus compatible), high enables SPI (up to 12 MHz). Internal 32 MHz oscillator provides timing reference; UVLO thresholds (2.5 V rising / 1.9 V falling) and thermal shutdown (150°C) ensure robust operation across industrial environments.

Key Specifications

Pinout & Package

LP5868TMRKPR is housed in a 5.0 mm × 5.0 mm, 40-pin VQFN package (RKP) with exposed thermal pad. The package supports high-power LED driving with low thermal impedance (RθJB = 12.0°C/W) and requires solder connection of the thermal pad to AGND for reliable operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LED matrix driver applications.

Compared with LP5866TMRKPR and LP5860TMRKPR, the LP5868TMRKPR strikes a balanced trade-off: sufficient 144-dot capacity for most premium UIs, optimal scan-line count for low-latency animation, and identical thermal, interface, and reliability specs-making it the default choice for mid-to-high-tier consumer and industrial displays.

Availability

LP5868TMRKPR is available at Aetrix Electronics and suitable for smart home appliance UIs, RGB mechanical keyboard backlighting, and outdoor keypad backlighting requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LP5868TMRKPR 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 high-reliability power management solutions for industrial, automotive, and consumer markets.

The LP5868TMRKPR belongs to TI's LP58xx family of high-current LED matrix drivers, engineered specifically for demanding human-interface applications requiring precise luminance control, robust fault handling, and seamless integration into resource-constrained microcontroller systems.

FAQ

What is the maximum LED dot count supported by the LP5868TMRKPR?

The LP5868TMRKPR supports up to 144 LED dots using its 8 × 18 matrix architecture (8 scan lines × 18 constant current sinks). This configuration enables full RGB pixel mapping for 48 independent pixels or monochrome/segmented indicators across large UI surfaces. The scan count is configurable from 6 to 8 lines via the Dev_initial register, allowing optimization for brightness, refresh rate, or EMI profile without hardware change.

Does the LP5868TMRKPR support both I²C and SPI interfaces simultaneously?

No, the LP5868TMRKPR supports only one serial interface at a time, selected by the IFS pin state: IFS = Low enables I²C (up to 1 MHz), and IFS = High enables SPI (up to 12 MHz). Both protocols share physical pins (SCL_SCLK, SDA_MOSI, ADDR0_MISO, ADDR1_SS), so the interface mode must be fixed at power-up. Hardware design must route IFS to a stable logic level and avoid floating connections to prevent undefined behavior.

How does the LP5868TMRKPR handle LED open and short circuit faults?

The LP5868TMRKPR integrates per-channel open-circuit detection (VLOD_TH = 0.25 V) and short-circuit detection (VLSD_TH = VLED – 1 V). When triggered, these functions flag faults in dedicated status registers readable via I²C/SPI. No automatic shutdown occurs-host firmware must poll or configure interrupt reporting (via VSYNC or GPIO) to initiate corrective action, such as disabling affected channels or logging failure for predictive maintenance.

What is the purpose of the VCAP pin on the LP5868TMRKPR?

The VCAP pin on the LP5868TMRKPR is the output of an internal LDO regulator, providing a stable 1.78 V supply for internal analog circuitry. A mandatory 1 μF ceramic capacitor must be placed between VCAP and GND, located as close as possible to the pin. Omitting or misplacing this capacitor causes unstable current regulation, increased PWM jitter, and potential communication errors-TI specifies placement tolerance ≤2 mm from the pin for reliable operation.

Can the LP5868TMRKPR drive 5 V LEDs directly from a 3.3 V system supply?

Yes, the LP5868TMRKPR can drive 5 V LEDs directly because it features separate VLED and VCC supplies: VLED (2.7–5.5 V) powers the high-side scan switches and LED anodes, while VCC (2.7–5.5 V) powers the logic core. A 3.3 V VCC supply is fully compatible with 5 V VLED operation, enabling mixed-rail designs where microcontrollers run at 3.3 V but LEDs require higher forward voltage. Ensure VLED decoupling (1 μF) and proper thermal pad grounding to maintain sink compliance at 100 mA.