Texas Instruments LP5864MRSMR

Overview

LP5864MRSMR from Texas Instruments is a 4 × 18 LED matrix driver IC with 18 precision constant-current sinks and 4 high-side PMOS scan switches, supporting up to 72 individually addressable LED dots or 24 RGB pixels. It delivers 0.1–50 mA per sink (VCC ≥ 3.3 V), ±5% device-to-device and channel-to-channel current accuracy, and operates across –40°C to +85°C (extended –55°C to +125°C). It enables high-fidelity LED animation in compact audio peripherals and smart home interfaces.

For engineers reviewing the LP5864MRSMR datasheet, LP5864MRSMR pinout, LP5864MRSMR application, or LP5864MRSMR equivalent, key selection criteria include its dual I²C/SPI interface (1 MHz / 12 MHz), 8-/16-bit per-dot PWM dimming with >20 kHz frequency to eliminate audible noise, full SRAM-based frame control, and integrated open/short detection for reliability-critical lighting systems.

Technical Context

The LP5864MRSMR implements time-multiplexed matrix driving using four programmable high-side PMOS switches (SW0–SW3) and 18 current sinks (CS0–CS17), enabling configurable 1–4-line scanning. Its internal 32-MHz oscillator feeds configurable PWM generators with phase-shift capability to balance transient power and suppress ghosting.

It integrates deghosting circuitry (upside/downside), low-brightness compensation across three current-sink groups, and full addressable SRAM for partial or full frame updates-reducing host MCU bandwidth demand while maintaining precise per-dot analog (8-bit DC, 7-bit CC, 3-bit MC) and PWM control.

Key Specifications

Pinout & Package

VQFN-32 package with 4 mm × 4 mm body and exposed thermal pad; RoHS-compliant, moisture-sensitive level 2a.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP5864RSMR, LP5864MRSMR adds extended temperature operation (–55°C to +125°C) without sacrificing performance or compatibility; versus LP5866MDBTR, it offers identical feature depth in a smaller VQFN-32 package optimized for space-constrained consumer electronics.

Availability

LP5864MRSMR is available at Aetrix Electronics and suitable for keyboard backlighting, smart speaker status indication, and pro-audio metering requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LP5864MRSMR 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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, precision, and energy efficiency.

The LP586x family was designed specifically for high-density, low-noise LED matrix applications in human-interface devices-prioritizing per-pixel control fidelity, thermal robustness, and minimal host MCU overhead.

FAQ

What is the maximum LED dot count supported by LP5864MRSMR?

The LP5864MRSMR supports up to 72 LED dots using its 4 high-side scan switches (SW0–SW3) and 18 constant-current sinks (CS0–CS17) in time-multiplexed matrix configuration. This equates to 24 RGB pixels when arranged as 3-color clusters. The LP5864MRSMR achieves this without external components, leveraging internal SRAM and programmable scan-line control to minimize host interface bandwidth.

Does LP5864MRSMR support both I²C and SPI interfaces simultaneously?

No - LP5864MRSMR uses a single hardware interface configurable as either I²C or SPI via the IFS pin. When IFS is low, SDA_MOSI and SCL_SCLK operate as I²C data/clock with 1-MHz max speed; when IFS is high, they become SPI MOSI/SCLK with 12-MHz max speed. ADDR0_MISO and ADDR1_SS serve dual roles as I²C address pins or SPI MISO/SS, ensuring pin compatibility across modes.

How does LP5864MRSMR handle LED open and short circuit detection?

LP5864MRSMR implements hardware-based per-sink fault detection: open-circuit detection triggers when sink voltage exceeds 0.25 V (VLOD_TH), and short-circuit detection activates when voltage drops below (VLED – 1 V) (VLSD_TH). These thresholds are fixed and monitored continuously during active operation. Detected faults are reported via status registers readable over I²C/SPI, enabling fail-safe UI behavior without host polling overhead.

What thermal performance can be expected from LP5864MRSMR in a typical 4-layer PCB layout?

In a standard 4-layer PCB with 1-in² 2-oz copper thermal pad connected to internal ground planes, LP5864MRSMR exhibits R_θJB = 12.3°C/W and R_θJA = 32.9°C/W. At full load (72 LEDs @ 10 mA), junction temperature rise remains below 45°C above ambient - well within the 150°C absolute max, even at +125°C ambient. Thermal shutdown activates at 150°C with 15°C hysteresis (THYS) to prevent cycling.

Can LP5864MRSMR drive RGB LEDs with independent color control?

Yes - LP5864MRSMR supports true per-color control via three independent 7-bit Color Current (CC) registers (CC_Group1–3), mapped to predefined current-sink groups (e.g., CS0/CS3/CS6… for red). Combined with global 3-bit Maximum Current (MC) and per-sink 8-bit Dot Current (DC), it enables precise white-point tuning, gamma correction, and dynamic color mixing across 24 RGB pixels without external DACs or current-setting resistors.