Texas Instruments TLC5941NT

Overview

TLC5941NT from Texas Instruments is a 16-channel constant-current LED driver IC with integrated 12-bit grayscale PWM control (4096 steps) and 6-bit dot correction (64 steps), supporting up to 80 mA per channel and LED open detection. It operates from 3.0 V to 5.5 V supply, accepts up to 17 V LED anode voltage, and features serial interface (SIN/SCLK/SOUT), XLAT latch, BLANK enable, and thermal error flag (TEF) for display backlighting and signage applications.

For engineers reviewing the TLC5941NT datasheet, TLC5941NT pinout, TLC5941NT application, or TLC5941NT equivalent, key selection considerations include its 28-pin PDIP package, 30 MHz serial data rate, IREF-set current programming, GS/DC register architecture, and dual-mode operation (grayscale vs. dot correction input).

Technical Context

The TLC5941NT implements a dual-register architecture: 192-bit grayscale (GS) register for per-channel 12-bit PWM brightness control and 96-bit dot correction (DC) register for per-channel 6-bit current scaling. Grayscale timing is driven by external GSCLK (up to 30 MHz), while serial data shift uses SCLK (also up to 30 MHz) with MSB-first 96- or 192-bit frames depending on MODE pin state.

It integrates LED open detection (LOD) that triggers when OUTn voltage falls below 0.3–0.4 V under active drive, and thermal error flag (TEF) activated at ~160°C junction temperature. Both errors assert open-drain XERR low and are latched into status bits readable via SOUT during serial readback.

Key Specifications

Pinout & Package

28-pin PDIP (Plastic Dual In-line Package), 0.600-inch body width, standard through-hole footprint. Thermal resistance θ_JA = 48°C/W (no heatsink). Pin 1 marked by notch or dot; pin count increases counter-clockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC5947PWR and MAX6966AUG+, the TLC5941NT uniquely offers through-hole PDIP packaging, hardware-accelerated dot correction, and integrated open-drain error reporting - making it optimal for legacy industrial designs requiring serviceability and robust fault visibility.

Availability

TLC5941NT is available at Aetrix Electronics and suitable for monochrome signage, full-color video walls, industrial HMIs, architectural lighting, and LED test equipment requiring stable component supply and long-term obsolescence management.

Supply support for TLC5941NT 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 experience in precision analog IC design and industrial-grade reliability.

The TLC5941NT belongs to TI's high-performance LED driver product line, engineered specifically for demanding visual display applications requiring accurate current regulation, grayscale fidelity, and real-time fault diagnostics.

FAQ

What is the maximum output current per channel for the TLC5941NT?

The TLC5941NT supports a maximum constant-current output of 80 mA per channel (OUT0–OUT15), set by an external resistor on the IREF pin using the formula I_OUT = 31.5 × (1.24 V / R_IREF). The device maintains ±4% channel-to-channel current matching across temperature and supply voltage variations, ensuring uniform LED brightness without external calibration.

How does the TLC5941NT implement dot correction and grayscale control?

The TLC5941NT uses two independent 96-bit (dot correction) and 192-bit (grayscale) internal registers. Dot correction (6-bit per channel) scales the max current linearly from 0% to 100%, while grayscale (12-bit per channel) controls PWM duty cycle for brightness. MODE pin selects between registers, and XLAT latches serial data - enabling simultaneous fine-tuning and dynamic dimming.

Does the TLC5941NT support daisy-chaining with other LED drivers?

Yes, the TLC5941NT supports seamless daisy-chaining via its SOUT-to-SIN interface. Serial data shifted into the first device's SIN propagates through SOUT to the next device's SIN, allowing cascaded control of multiple TLC5941NTs with only three MCU pins (SCLK, XLAT, SIN). Status bits (LOD/TEF) can also be read back sequentially from the last device's SOUT.

What fault detection capabilities does the TLC5941NT provide?

The TLC5941NT integrates two hardware fault detectors: LED Open Detection (LOD) triggers when an output voltage drops below 0.3–0.4 V under active drive, and Thermal Error Flag (TEF) activates at ~160°C junction temperature. Both assert the open-drain XERR pin low and are latched into a status register readable via SOUT - enabling rapid system-level diagnostics without polling.

What is the role of the BLANK pin on the TLC5941NT?

The BLANK pin is an active-high global enable/disable signal for all 16 outputs. When HIGH, it forces OUT0–OUT15 OFF and resets the internal grayscale counter - essential for frame blanking, strobe synchronization, or system-level PWM dimming. Unlike software-based blanking, BLANK operates at hardware level with nanosecond response, eliminating timing jitter in high-speed display applications.