Texas Instruments TLC5944PWPRG4

Overview

TLC5944PWPRG4 from Texas Instruments is a 16-channel, 12-bit PWM constant-current LED sink driver with integrated 6-bit dot correction and pre-charge FET. It delivers up to 60 mA per channel, supports 33-MHz grayscale clocking, and features LED open detection (LOD), thermal error flag (TEF), and pre-thermal warning (PTW). It is used in multiplexed monochrome and full-color LED displays requiring precise brightness uniformity and ghosting suppression.

For engineers reviewing the TLC5944PWPRG4 datasheet, TLC5944PWPRG4 pinout, TLC5944PWPRG4 application, or TLC5944PWPRG4 equivalent, key selection considerations include its HTSSOP-28 PowerPAD™ package, 4096-step grayscale resolution, ±1% channel-to-channel current accuracy, continuous LOD during display, and daisy-chainable serial interface for scalable LED matrix control.

Technical Context

The TLC5944PWPRG4 implements dual-stage serial control: grayscale data (12 bits × 16 channels) and dot correction data (6 bits × 16 channels) are loaded via shared SIN/SCLK/DCSEL/XLAT signals, with separate GSCLK (33 MHz) and BLANK timing control. Its internal pre-charge FET activates synchronously with BLANK low to suppress ghosting in multiplexed LED systems.

It integrates three independent fault monitors: LOD detects open or GND-short LEDs during active display with auto-output-off; TEF triggers thermal shutdown at +162°C (±13°C) with +10°C hysteresis; PTW asserts at +120°C (±15°C) while maintaining output operation. All error status is readable via SOUT as Status Information Data (SID).

Key Specifications

Pinout & Package

Package: HTSSOP-28 PowerPAD™ (thermally enhanced, 28-pin thin shrink small-outline package with exposed thermal pad).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC5947PWR and IS31FL3731-QFLS4-TR, the TLC5944PWPRG4 uniquely combines multiplex-optimized pre-charge FET, continuous LOD during operation, and dual thermal thresholds - making it the only option among the three qualified for mission-critical outdoor LED signage with zero-tolerance for ghosting or undetected failures.

Availability

TLC5944PWPRG4 is available at Aetrix Electronics and suitable for LED signboards, monochrome/multicolor display modules, full-color video walls, and industrial status indicators requiring stable component supply, long-term lifecycle support, and guaranteed thermal reliability.

Supply support for TLC5944PWPRG4 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 precision analog ICs.

The TLC5944PWPRG4 belongs to TI's high-accuracy LED driver product line, designed specifically for demanding multiplexed LED display applications where brightness uniformity, fault resilience, and thermal robustness are non-negotiable.

FAQ

What is the maximum LED supply voltage supported by the TLC5944PWPRG4?

The TLC5944PWPRG4 supports a VUP (pre-charge supply) voltage up to +15 V, enabling direct drive of high-V_f LED strings (e.g., white or blue LEDs in series) without external boost circuitry. This rating is absolute maximum; recommended operating range is 3.0 V to 15 V. The VUP pin powers both the pre-charge FET and the constant-current sink stage, and must be decoupled with a local ceramic capacitor.

How does the TLC5944PWPRG4 handle LED open detection during active display?

The TLC5944PWPRG4 performs continuous LED open detection (LOD) during normal grayscale PWM operation - not just during blanking intervals. It monitors voltage at each OUTx pin during the active sink period; if voltage exceeds 0.3 V (typical), it flags an open or GND-short condition and asserts XERR. When LOD is detected, the affected channel is automatically disabled to prevent erroneous illumination, and the status is retained for readback via SOUT as part of Status Information Data (SID).

Can the TLC5944PWPRG4 be daisy-chained, and what interface signals are required?

Yes, the TLC5944PWPRG4 supports seamless daisy-chaining using only four signals: SIN (input), SOUT (output), SCLK (shared clock), and XLAT (latch strobe). DCSEL selects register type (grayscale or dot correction), and GSCLK/BLANK are common across all devices. Data propagates serially: SIN → SOUT of first IC → SIN of second IC, etc. Each device loads its own 16-channel data from the stream, enabling scalable control of hundreds of LEDs with minimal MCU resources.

What is the role of the VUP pin, and how does it differ from VCC?

VUP is the dedicated supply for the pre-charge FET and constant-current sink stage, rated up to +15 V and electrically isolated from the digital logic supply VCC (3.0–5.5 V). This separation allows the TLC5944PWPRG4 to drive LEDs with forward voltages exceeding VCC - for example, a 12-V LED string powered by VUP while the MCU interface runs at 3.3 V on VCC. VUP must be externally decoupled and routed with low impedance to minimize noise coupling into analog current paths.

How is dot correction data applied to adjust individual LED brightness on the TLC5944PWPRG4?

Dot correction (DC) data are 6-bit values (0–63 decimal) loaded into a dedicated DC shift register and latched to per-channel DC data latches. Each channel's output current is calculated as I_OUTn = I_OLCMax × (DC_n/63), where I_OLCMax is set globally by the IREF resistor. DC data must be written *before* enabling outputs via BLANK low; they persist across GSCLK cycles and are independent of grayscale data, allowing permanent calibration of LED binning mismatches.