Texas Instruments TLC5929RGER

Overview

TLC5929RGER from Texas Instruments is a 16-channel constant-current LED sink driver with 7-bit global brightness control (128 steps), ±1% typical channel-to-channel current accuracy, and integrated LED open/short detection. It operates from 3.0 V to 5.5 V supply voltage, supports up to 50 mA per channel at VCC > 3.6 V, and delivers precise current regulation for high-reliability LED signage and illumination systems.

For engineers reviewing the TLC5929RGER datasheet, TLC5929RGER pinout, TLC5929RGER application, or TLC5929RGER equivalent, key selection considerations include its QFN-24 package thermal performance (θJCbot = 6.2°C/W), 33 MHz serial data rate, 40 ns minimum BLANK pulse width, invisible detection mode (IDM) for fault diagnosis during output-off states, and power-save mode consuming only 10 µA typical.

Technical Context

The TLC5929RGER implements a serial-shift-register architecture with dual 16-bit latches-one for output on/off control and one for function configuration (global brightness, LSD voltage select, error flags). Its constant-current regulation uses a single external IREF resistor to set maximum sink current across all 16 channels, with programmable 7-bit global scaling applied digitally in real time.

Error diagnostics include LED open detection (LOD), LED short detection (LSD) with four selectable threshold voltages (0.32×VCC to 0.68×VCC), output leakage detection (OLD ≥3 µA), pre-thermal warning (138°C), and thermal shutdown (150°C). All flags are readable via the same serial interface used for configuration and data loading.

Key Specifications

Pinout & Package

Package: QFN-24 (RGE), 4 mm × 4 mm, 0.5 mm pitch, exposed thermal pad (bottom side) for enhanced heat dissipation. Thermal resistance θJCbot = 6.2°C/W enables high-current operation in compact layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC5929RGER, TLC5940RHBR offers finer grayscale control but lacks fault detection and thermal protection, while MAX7219CWG+ provides plug-and-play digit driving but cannot match the channel count, current accuracy, or diagnostic depth required for large-scale LED signage.

Availability

TLC5929RGER is available at Aetrix Electronics and suitable for variable message signs (VMS), architectural illumination systems, LED power supply modules, and industrial panel displays requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TLC5929RGER 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 expertise in high-reliability industrial and automotive IC design.

The TLC5929 product line was engineered specifically for high-channel-count LED signage and illumination applications demanding precision current regulation, comprehensive fault diagnostics, and robust thermal management in space-constrained designs.

FAQ

What is the maximum output current per channel for the TLC5929RGER?

The TLC5929RGER supports up to 50 mA per channel when VCC exceeds 3.6 V, set by the external RIREF resistor. At VCC ≤ 3.6 V, the maximum is 40 mA. The actual current is determined by both RIREF value and the 7-bit global brightness control setting-e.g., with RIREF = 1.32 kΩ and BC = 7Fh (127), each channel delivers ~50 mA. The TLC5929RGER datasheet specifies ±1% typical channel-to-channel matching under these conditions.

How does the invisible detection mode (IDM) work in the TLC5929RGER?

The TLC5929RGER's invisible detection mode (IDM) performs LED open detection (LOD) and LED short detection (LSD) even when all outputs are turned OFF via the BLANK pin or latch data. This is achieved by briefly pulsing internal test currents during inactive periods-avoiding visible LED flicker during diagnostics. IDM is configured via control bits in the function latch and reported through the same serial interface used for data loading, enabling remote fault verification without disrupting display operation.

Can the TLC5929RGER be daisy-chained, and what is the maximum number of devices supported?

Yes, the TLC5929RGER supports seamless daisy-chaining using its SOUT-to-SIN interface. Each device shifts out its MSB on SOUT at the rising edge of SCLK, allowing unlimited cascading without additional logic. The practical limit depends on total serial data length and timing margins: for a 17-bit shift register per device, 10 chips require 170-bit frames, still within the 33 MHz SCLK specification if setup/hold times are maintained. The TLC5929RGER reference designs demonstrate reliable operation with >20 devices in series.

What thermal management features does the TLC5929RGER provide?

The TLC5929RGER integrates pre-thermal warning (PTW) at 138°C and thermal shutdown (TSD) at 150°C, both referenced to junction temperature. Hysteresis (5–20°C) prevents oscillation near trip points. Its QFN-24 RGE package includes an exposed thermal pad with θJCbot = 6.2°C/W, enabling direct PCB copper pour attachment for efficient heat transfer. These features allow sustained 50 mA/channel operation in compact enclosures-verified in TI's thermal characterization reports for the TLC5929RGER.

Does the TLC5929RGER support power-save mode, and how is it activated?

Yes, the TLC5929RGER includes a dedicated power-save mode drawing only 10 µA typical supply current. It is activated by writing all-zero data to the output on/off latch *and* setting the PSMODE bit in the control data latch-both accomplished via the serial interface. Once enabled, the device maintains latch states but disables internal clocks and bias circuits. The TLC5929RGER exits power-save mode automatically on the next valid SCLK edge, resuming normal operation within 20 µs (tD4).