Texas Instruments TLC5923DAP

Overview

TLC5923DAP from Texas Instruments is a 16-channel constant-current LED sink driver with per-channel 7-bit dot correction (128-step brightness adjustment), ±1% typical current accuracy, and integrated LED open detection (LOD) and thermal error flag (TEF). It operates from 3.0 V to 5.5 V supply, supports up to 80 mA per channel, and targets high-reliability LED display backlighting and signage applications.

For engineers reviewing the TLC5923DAP datasheet, TLC5923DAP pinout, TLC5923DAP application, or TLC5923DAP equivalent, key selection criteria include its 32-pin HTSSOP PowerPAD™ package, 30 MHz serial interface, BLANK-controlled global output disable, and dual-mode MODE pin for On/Off vs. dot-correction data loading.

Technical Context

The TLC5923DAP implements two independent 16-bit shift register paths-one for 16-bit On/Off control and another for 112-bit dot correction (7 bits × 16 channels)-selected via the MODE pin. Its constant-current sink architecture uses a single external IREF resistor to set maximum channel current (IMAX = 40 × V_IREF/R_IREF, where V_IREF = 1.24 V typ).

Error handling is hardware-automated: LOD detects open LEDs when BLANK = L, ON/OFF = H, and OUTn voltage < 0.3 V (typ), while TEF triggers at ~160°C junction temperature. Both assert XERR (open-drain) low. Output delay is graduated (20 ns/channel) to suppress inrush current.

Key Specifications

Pinout & Package

Package: 32-pin HTSSOP (DAP) with exposed PowerPAD™ thermal pad (soldered to PCB ground plane for enhanced thermal dissipation; 42.54 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 TLC5923DAP, TLC5940RHBR offers higher PWM resolution but sacrifices integrated fault detection and single-resistor simplicity, while IS31FL3731-QFLS4-TR trades current capability and thermal safety for compactness and I²C ease-of-use-making TLC5923DAP optimal for robust, high-current LED signage with minimal BOM overhead.

Availability

TLC5923DAP is available at Aetrix Electronics and suitable for monocolor LED signboards, full-color display backlights, multicolor architectural lighting panels, and industrial status indicator arrays requiring stable component supply across extended production lifecycles.

Supply support for TLC5923DAP 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 LED driver ICs.

The TLC5923 product line was designed specifically for high-channel-count LED signage and backlighting systems requiring precise current matching, hardware-based fault detection, and simplified thermal management via PowerPAD™ packaging.

FAQ

What is the maximum output current per channel for the TLC5923DAP?

The TLC5923DAP supports up to 80 mA per channel (IOLC) under recommended operating conditions. This maximum is set by an external resistor connected to the IREF pin, where IMAX = 40 × V_IREF/R_IREF and V_IREF = 1.24 V typical. The absolute maximum rating is 90 mA, but operation above 80 mA is not guaranteed across temperature and voltage ranges. For reliable long-term performance, design within the 80 mA limit specified in the TLC5923DAP datasheet.

How does the MODE pin affect serial data loading in the TLC5923DAP?

The MODE pin on the TLC5923DAP selects between two distinct serial data paths: when MODE = L, the internal 16-bit On/Off shift register is active, accepting one bit per channel; when MODE = H, the 112-bit dot-correction shift register (7 bits × 16 channels) is enabled. XLAT behavior also changes-rising edge for On/Off latching, level-high for dot-correction write. Misalignment of MODE during data transfer corrupts register contents in the TLC5923DAP.

Can the TLC5923DAP detect open LEDs while the outputs are disabled?

No-the TLC5923DAP LED open detection (LOD) requires BLANK = L, ON/OFF = H, and OUTn voltage < 0.3 V (typical) to trigger. If BLANK = H, all outputs are forced OFF and LOD cannot activate, even if an LED is disconnected. To perform diagnostics, BLANK must be held low while driving the suspect channel ON; LOD status is then readable via SOUT after XLAT assertion. This behavior is inherent to the TLC5923DAP's fault-detection architecture.

What thermal management considerations apply to the TLC5923DAP in continuous operation?

The TLC5923DAP uses a PowerPAD™ HTSSOP package requiring soldering of the exposed thermal pad to a PCB ground plane. With proper 2 oz. copper connection, it achieves 42.54 mW/°C derating above 25°C and 5318 mW max power dissipation at 25°C. At 85°C ambient and full 80 mA per channel, thermal simulation shows junction temperatures exceeding safe limits without adequate copper area-thus the TLC5923DAP demands ≥4 cm² of inner-layer ground pour beneath the PowerPAD™ for sustained operation.

Is the TLC5923DAP compatible with 3.3 V microcontrollers for serial communication?

Yes-the TLC5923DAP supports CMOS-level inputs (VIH = 0.8 × VCC, VIL = 0.2 × VCC) and operates from VCC = 3.0 V to 5.5 V. When powered at 3.3 V, its SIN, SCLK, XLAT, MODE, and BLANK inputs accept 3.3 V logic directly from standard microcontrollers without level shifting. SOUT and XERR outputs are open-drain and require external pull-ups, making them fully interoperable with 3.3 V or 5 V systems. This ensures seamless integration with modern low-voltage controllers in the TLC5923DAP design.