Texas Instruments TLC5951RHAR

Overview

TLC5951RHAR from Texas Instruments is a 24-channel, constant-current sink LED driver IC with integrated 12-bit PWM grayscale control, 7-bit dot correction, and independent 8-bit global brightness control per RGB color group. It delivers up to 40 mA per channel, supports 15 V LED supply, operates from 3 V to 5.5 V VCC, and enables precise full-color LED display driving in daisy-chained configurations.

For engineers reviewing the TLC5951RHAR datasheet, TLC5951RHAR pinout, TLC5951RHAR application, or TLC5951RHAR equivalent, key selection considerations include its triple independent grayscale clocks (GSCKR/GSCKG/GSCKB), continuous LED open/short detection (LOD/LSD), thermal shutdown with auto-restart, and support for HTSSOP-38 packaging with exposed thermal pad.

Technical Context

The TLC5951RHAR implements a dual serial interface architecture: a 288-bit common shift register (GSSIN/GSSCK/GSLAT/GSSOUT) handles grayscale, dot correction, and brightness data, while a separate 216-bit dedicated shift register (DCSIN/DCSCK/DCSOUT) manages dot correction and global brightness updates. Data latching is controlled by GSLAT edge timing relative to GSSCK, enabling deterministic transfer to GS or DC/BC latches.

Each of the three 8-channel output groups (RED/GREEN/BLUE) features independent grayscale clock inputs (GSCKR/GSCKG/GSCKB), grouped delay sequencing to suppress inrush current, and paired-output switching with 24 ns typical inter-pair delay. Continuous LOD/LSD monitoring operates in parallel with active PWM operation without interrupting display timing.

Key Specifications

Pinout & Package

Package: HTSSOP-38 with exposed thermal pad (12.50 mm × 6.20 mm body). Thermal pad must be soldered to PCB ground plane for reliable thermal performance at full load.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC5951RHAR, TLC5947RTQT offers simpler control but lacks precision calibration, while IS31FL3731-QFLS4 trades PWM resolution and clock flexibility for protocol convenience-neither matches TLC5951RHAR's combination of 12-bit grayscale, hardware dot correction, and independent RGB timing.

Availability

TLC5951RHAR is available at Aetrix Electronics and suitable for full-color LED displays, LED signboards, and industrial HMI applications requiring stable component supply, long-term lifecycle support, and traceable sourcing for production programs.

Supply support for TLC5951RHAR 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 U.S.-based semiconductor company specializing in analog, embedded processing, and power management technologies, with decades of leadership in precision LED driver innovation.

The TLC5951RHAR belongs to TI's high-accuracy LED driver product line, designed specifically for professional-grade RGB display systems demanding tight current matching, real-time fault diagnostics, and daisy-chain scalability.

FAQ

What is the maximum LED supply voltage supported by the TLC5951RHAR?

The TLC5951RHAR supports LED supply voltages up to 15 V on its OUTx pins, independent of the 3 V to 5.5 V VCC logic supply. This allows direct driving of multi-LED series strings without external boost circuitry, provided the voltage drop across the current sink remains within specification. The TLC5951RHAR's output stage is rated for 16 V absolute maximum, ensuring margin for transient spikes.

How does the TLC5951RHAR implement dot correction and where is it stored?

The TLC5951RHAR implements 7-bit dot correction per channel using a dedicated 216-bit shift register accessible via DCSIN/DCSCK. Correction values are loaded into the DC data latch and applied multiplicatively to grayscale values before PWM generation. Dot correction data persist across power cycles only if retained externally-the TLC5951RHAR itself does not include nonvolatile storage for DC settings.

Can the TLC5951RHAR be daisy-chained, and what interface signals are required?

Yes, the TLC5951RHAR supports seamless daisy-chaining using GSSOUT-to-GSSIN and DCSOUT-to-DCSIN connections between devices. Each device consumes 288 bits of grayscale data and 216 bits of dot correction/brightness data per frame. The shared GSSCK and DCSCK clocks propagate synchronously, while individual GSLAT and XBLNK lines maintain per-device timing control.

What thermal management is required for the TLC5951RHAR in HTSSOP-38 package?

The TLC5951RHAR in HTSSOP-38 (RHA) package requires soldering of the exposed thermal pad to a minimum 200 mm² copper pour tied to GND for effective heat dissipation. At 40 mA per channel and 85°C ambient, thermal resistance is 27.8°C/W (junction-to-ambient); insufficient copper area risks exceeding the 125°C junction limit. TI recommends ≥4 thermal vias under the pad.

Does the TLC5951RHAR support both hardware and software reset mechanisms?

The TLC5951RHAR provides hardware reset via the XBLNK pin: asserting XBLNK low forces all outputs off, resets grayscale counters to zero, and initializes the PWM timing controller. There is no dedicated software reset command; however, writing all-zero grayscale data combined with a GSLAT pulse achieves functional reset of displayed content without affecting dot correction or brightness registers.