Texas Instruments TLC5928RGET

Overview

TLC5928RGET from Texas Instruments is a 16-channel constant-current LED sink driver with integrated LED open detection (LOD) and pre-thermal warning (PTW). It delivers up to 35 mA per channel, supports 35-MHz serial data transfer, features 20-ns BLANK pulse width, and operates from 3.0 V to 5.5 V supply - enabling high-fidelity LED video displays and message boards requiring precise current control and fault monitoring.

For engineers reviewing the TLC5928RGET datasheet, TLC5928RGET pinout, TLC5928RGET application, or TLC5928RGET equivalent, key selection criteria include its QFN-24 package thermal performance, daisy-chainable serial interface (SIN/SCLK/LAT/BLANK/SOUT), ±1% channel-to-channel current accuracy, LOD threshold of 0.30 V, and junction temperature monitoring at +138 °C typical.

Technical Context

The TLC5928RGET implements a 16-bit serial shift register followed by a parallel latch for on/off control of all 16 constant-current sinks. Its internal reference voltage (1.20 V) sets output current via an external IREF resistor, with line regulation ±0.5%/V and load regulation ±1%/V.

Two independent error-detection circuits operate in real time: LOD monitors each OUTn voltage during conduction (triggering at ≤0.30 V), while PTW asserts when junction temperature exceeds +138 °C. Both status bits are readable via SOUT after latching with BLANK and LAT edges.

Key Specifications

Pinout & Package

Package: QFN-24 (RGE), 4 mm × 4 mm, 0.5 mm pitch, exposed thermal pad (not internally connected to GND; must be soldered to PCB ground plane).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC5928RGET, TLC5940RHBR offers superior grayscale resolution but requires external fault monitoring, while MAX7219CWG+ integrates display scanning logic but lacks per-channel current programming and thermal safety features.

Availability

TLC5928RGET is available at Aetrix Electronics and suitable for LED video displays, outdoor message boards, and architectural illumination requiring stable component supply, long-term production continuity, and RoHS-compliant packaging.

Supply support for TLC5928RGET 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 TLC5928 product line was designed specifically for high-reliability LED signage and display systems requiring integrated fault detection, tight current matching, and robust serial control - targeting industrial and commercial lighting applications.

FAQ

What is the maximum LED supply voltage supported by the TLC5928RGET?

The TLC5928RGET supports LED power-supply voltages up to 17 V at its OUT0–OUT15 pins. This allows direct connection to common 12 V and 24 V LED strings without intermediate voltage translation, provided the constant-current sink remains within its 35 mA per-channel limit and thermal limits are observed under continuous operation.

How does the LED open detection (LOD) function work in the TLC5928RGET?

The TLC5928RGET's LOD circuit monitors the voltage at each OUTn pin while that channel is actively sinking current. If VOUTn drops to ≤0.30 V (typical), the corresponding LOD bit is set to '1' in the status information data (SID) register. This condition indicates either an open LED or one shorted to GND. The status is readable via SOUT after latching with BLANK and LAT edges.

Can the TLC5928RGET be used in daisy-chain configuration?

Yes, the TLC5928RGET supports daisy-chaining via its SIN and SOUT pins. Serial data written to SIN of the first device propagates through SOUT to SIN of the next, enabling control of multiple TLC5928RGET devices with a single microcontroller SPI-like interface. LAT and BLANK signals must be shared across all devices in the chain for synchronized update and blanking.

What is the role of the IREF pin on the TLC5928RGET?

The IREF pin on the TLC5928RGET connects to an external resistor tied to GND, establishing the reference current for all 16 constant-current sinks. With an internal 1.20 V reference, the sink current per channel is calculated as IOUT = 42 × (1.20 V / RIREF). For example, a 1.44 kΩ resistor sets IOUT ≈ 35 mA, as specified in the datasheet's Table 1.

Does the TLC5928RGET provide thermal protection or shutdown?

The TLC5928RGET does not implement automatic thermal shutdown. Instead, it provides pre-thermal warning (PTW) - asserting a status bit when junction temperature exceeds +138 °C (typical). This allows the host controller to proactively reduce LED duty cycle or brightness before reaching critical temperatures. The device continues operating during PTW conditions unless externally disabled via BLANK.