Texas Instruments TLC5923RHBR

Overview

TLC5923RHBR from Texas Instruments is a 16-channel constant-current LED sink driver with 7-bit per-channel dot correction (128-step brightness adjustment), ±1% typical current accuracy, and 30 MHz serial interface clock rate. It operates from 3.0 V to 5.5 V supply, supports up to 80 mA per channel, and integrates LED open detection (LOD) and thermal error flag (TEF) for display reliability in outdoor signage.

For engineers reviewing the TLC5923RHBR datasheet, TLC5923RHBR pinout, TLC5923RHBR application, or TLC5923RHBR equivalent, key selection criteria include its QFN-32 package with PowerPAD™ thermal enhancement, mode-selectable 16-bit ON/OFF vs. 112-bit dot-correction data loading, BLANK-controlled global output disable, and open-drain XERR error reporting for system-level fault monitoring.

Technical Context

The TLC5923RHBR implements dual-mode serial control via MODE pin: low for 16-bit ON/OFF register latching on XLAT rising edge, high for 112-bit dot-correction register loading under XLAT high-level enable. Its internal architecture includes independent 7-bit DC registers per channel, a shared IREF reference input setting max current via external resistor, and graduated 20 ns inter-channel output delay to suppress inrush current.

LED open detection triggers when BLANK = L, ON/OFF bit = 1, and OUTn voltage < 0.3 V (typical); thermal error activates at ~160°C junction temperature. Both flags drive the open-drain XERR output, which requires external pull-up and supports wired-OR fault aggregation across cascaded devices.

Key Specifications

Pinout & Package

Package: 32-pin QFN (RHB), 5 mm × 5 mm, exposed thermal pad (PowerPAD™) soldered to PCB ground plane for enhanced thermal dissipation (27.86 mW/°C derating above 25°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC5923RHBR, TLC5940RHBR trades dot-correction flexibility for deeper grayscale PWM and eliminates external R_IREF, while MAX6966AUG+T sacrifices per-channel analog tuning for I²C ease-of-use and tighter thermal protection - both require layout changes and firmware adaptation.

Availability

TLC5923RHBR is available at Aetrix Electronics and suitable for monocolor signboards, multicolor displays, and display backlighting requiring stable component supply, long-term production continuity, and automotive-grade thermal resilience.

Supply support for TLC5923RHBR 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 ICs, with decades of expertise in high-reliability LED driver design.

The TLC5923RHBR belongs to TI's precision LED driver product line, engineered specifically for outdoor signage and industrial displays demanding robust fault detection, thermal stability, and per-channel brightness calibration.

FAQ

What is the maximum output current per channel for the TLC5923RHBR?

The TLC5923RHBR supports up to 80 mA per channel (OUT0–OUT15) under recommended operating conditions. This maximum current is set by an external resistor connected between IREF and GND, with R_IREF ≥ 600 Ω. The actual current scales as I_OUT = 40 × (1.24 V / R_IREF), yielding 80 mA at R_IREF = 600 Ω. Current accuracy is ±1% typical across channels and temperature.

How does the TLC5923RHBR implement dot correction, and what is its resolution?

The TLC5923RHBR implements per-channel dot correction using a 7-bit digital value (0–127) loaded into dedicated DC registers. Each channel's output current is scaled linearly from 0% to 100% of the maximum set by IREF. Dot-correction data is loaded as a 112-bit packet (16 × 7 bits) when MODE = H, and latched into registers on XLAT high-level assertion - enabling precise brightness matching across LED batches in the TLC5923RHBR.

What fault detection features does the TLC5923RHBR provide, and how are they reported?

The TLC5923RHBR integrates LED Open Detection (LOD) and Thermal Error Flag (TEF) circuits. LOD triggers when BLANK = L, ON/OFF bit = 1, and OUTn voltage < 0.3 V (typical); TEF activates at ~160°C junction temperature. Both flags drive the open-drain XERR pin low, supporting wired-OR fault aggregation. LOD status can also be read back serially via SOUT after XLAT-triggered latching.

Can multiple TLC5923RHBR devices be cascaded, and what is required for daisy-chaining?

Yes, TLC5923RHBR devices support daisy-chaining via SOUT-to-SIN connection. The serial interface uses MSB-first data transfer with MODE-selectable register widths (16-bit ON/OFF or 112-bit DC). Cascaded systems require only three MCU lines (SCLK, XLAT, MODE) plus one shared SOUT return path. Data throughput scales linearly: n devices need 16n or 112n clock cycles per update, depending on MODE setting.

What is the role of the BLANK pin in the TLC5923RHBR, and how does it interact with other controls?

The BLANK pin (Pin 2) provides global output disable: when HIGH, all 16 OUTn channels are forced OFF regardless of their ON/OFF register state or dot-correction settings. When LOW, outputs operate normally under register control. BLANK is asynchronous and overrides all other controls - essential for flicker-free blanking in video applications and safe startup/shutdown sequencing in the TLC5923RHBR.