Texas Instruments TLC5971PWPR

Overview

TLC5971PWPR from Texas Instruments is a 12-channel, 16-bit PWM RGB LED driver with integrated 3.3-V linear regulator, constant-current sink outputs (60 mA per channel), enhanced spectrum grayscale control (65536 steps), and global brightness control (128 steps per color group). It supports cascading for large LED arrays in architectural lighting and stage displays.

For engineers reviewing the TLC5971PWPR datasheet, TLC5971PWPR pinout, TLC5971PWPR application, or TLC5971PWPR equivalent, key selection criteria include its 20-pin HTSSOP package, dual power options (6–17 V internal regulator or 3–5.5 V direct supply), thermal shutdown with auto-restart, and 20 MHz data clock capability for high-refresh-rate LED systems.

Technical Context

The TLC5971PWPR implements a 224-bit shift register with two-wire serial interface (SDTI/SCKI) and daisy-chainable SDTO/SCKO outputs. Its internal oscillator (6–12 MHz) or external clock enables programmable grayscale timing, while independent red/green/blue channel groups support synchronized or staggered PWM updates.

Each of the 12 output channels (OUTR0–OUTR3, OUTG0–OUTG3, OUTB0–OUTB3) is a constant-current sink with ±1% channel-to-channel accuracy and 17-V LED supply tolerance. Global brightness control operates independently per color group via 7-bit BC registers, and thermal shutdown triggers at 150°C with 5–20°C hysteresis.

Key Specifications

Pinout & Package

Package: 20-pin HTSSOP (PWP), 6.50 mm × 4.40 mm body size, PowerPAD exposed thermal pad on bottom side for enhanced heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC5947RTQT and IS31FL3731-QFLS4, the TLC5971PWPR uniquely combines 16-bit grayscale, integrated 3.3-V regulation, and hardware auto-repeat in a compact 20-pin HTSSOP-making it optimal for medium-complexity RGB string applications demanding high fidelity and minimal BOM count.

Availability

TLC5971PWPR is available at Aetrix Electronics and suitable for architectural lighting, stage equipment, RGB signage, and automotive interior lighting requiring stable component supply and long-term production continuity.

Supply support for TLC5971PWPR 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 connectivity technologies with decades of LED driver innovation.

The TLC5971 product line delivers high-precision, thermally robust RGB LED drivers for professional lighting systems where color accuracy, reliability, and ease of cascade configuration are essential design requirements.

FAQ

What power supply options does the TLC5971PWPR support?

The TLC5971PWPR supports two distinct power configurations: (1) 6–17 V applied to VCC powers an internal linear regulator that generates 3.3 V on VREG, or (2) 3–5.5 V supplied directly to VREG bypasses the internal LDO. Both modes allow concurrent operation of the 12 constant-current outputs. The TLC5971PWPR datasheet specifies absolute maximum ratings and recommended operating conditions for each mode.

How is full-scale output current set on the TLC5971PWPR?

Full-scale output current for all 12 channels is set by a single external resistor (RIREF) connected between IREF and GND. For example, a 0.82 kΩ resistor yields 60 mA per channel (typical), while a 24 kΩ resistor sets 2 mA. The relationship is inverse and linear: IOUT = 1.21 V / RIREF. Direct grounding of IREF disables all outputs. The TLC5971PWPR electrical characteristics table confirms ±1% channel-to-channel matching under this configuration.

Does the TLC5971PWPR support daisy-chaining, and how is it implemented?

Yes, the TLC5971PWPR supports unlimited daisy-chaining via dedicated SDTO (serial data out) and SCKO (serial clock out) pins. SDTO outputs the MSB of the internal 224-bit shift register, and SCKO re-times the input clock for skew-free propagation. This allows cascading dozens of TLC5971PWPR devices without external buffers or timing recalibration - a core feature confirmed in the functional block diagram and pin functions section of the TLC5971PWPR datasheet.

What is the purpose of the BLANK pin functionality in the TLC5971PWPR?

The TLC5971PWPR does not have a dedicated BLANK pin; instead, BLANK is a configurable bit within the 224-bit data register. When asserted, it forces immediate latching of grayscale data to all outputs, eliminating display tearing during dynamic updates. This hardware-controlled timing reset is critical for synchronizing multiple TLC5971PWPR devices in large LED arrays - a feature explicitly documented in the "Device Functional Modes" and timing diagrams of the TLC5971PWPR datasheet.

How does thermal management work in the TLC5971PWPR?

The TLC5971PWPR integrates thermal shutdown (TSD) that activates at 150°C junction temperature, with 5–20°C hysteresis for auto-restart. Its HTSSOP package includes a PowerPAD exposed thermal pad on the bottom side, enabling low θJB (19.3°C/W) when soldered to a 2-oz copper PCB area. The TLC5971PWPR thermal information table specifies derating curves and power dissipation limits up to 85°C ambient, ensuring reliable operation in enclosed lighting enclosures.