Texas Instruments TLC5923DAPG4

Overview

TLC5923DAPG4 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 backlights and signage requiring precise current matching across channels.

For engineers reviewing the TLC5923DAPG4 datasheet, TLC5923DAPG4 pinout, TLC5924DAPG4 application, or TLC5923DAPG4 equivalent, key selection criteria include its 32-pin HTSSOP PowerPAD™ package, 30 MHz serial interface, BLANK-controlled global output disable, and dual-mode serial control (ON/OFF vs. dot-correction data via MODE pin).

Technical Context

The TLC5923DAPG4 implements two independent 16-bit shift register paths-one for 1-bit ON/OFF control and another for 112-bit (16 × 7-bit) dot-correction data-selected by the MODE pin. Its constant-current sinks are calibrated against a 1.24 V internal reference at IREF, scaling output current by a fixed 40× factor relative to external R_IREF.

Each output features programmable 20 ns inter-channel delay to suppress inrush current, while LOD monitors OUTn voltage (<0.3 V typ.) during active sinking to detect open LEDs, and TEF triggers at ~160°C junction temperature. Both errors assert XERR as an open-drain fault signal.

Key Specifications

Pinout & Package

32-pin HTSSOP (DAP) package with exposed thermal pad soldered to PCB ground plane for enhanced power dissipation (42.54 mW/°C derating above 25°C).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-channel constant-current LED driver applications.

Compared with TLC5923DAPG4, TLC5940RHBR offers superior grayscale but no fault reporting, while MAX6966ATL+ simplifies bus interface at the cost of reduced current capability and missing LOD diagnostics - making TLC5923DAPG4 optimal for robust, high-brightness LED signage with built-in reliability monitoring.

Availability

TLC5923DAPG4 is available at Aetrix Electronics and suitable for monocolor signboards, multicolor displays, and display backlighting requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial OEM programs.

Supply support for TLC5923DAPG4 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 high-reliability power management solutions.

The TLC5923DAPG4 belongs to TI's LED driver product line, designed specifically for high-accuracy, multi-channel constant-current LED control in signage, backlighting, and architectural lighting applications.

FAQ

What is the maximum LED supply voltage supported by the TLC5923DAPG4?

The TLC5923DAPG4 supports up to 17 V applied to its OUT0–OUT15 pins, enabling direct connection to common LED strings without external voltage translation. This rating is specified under recommended operating conditions and remains valid across the full –40°C to +85°C temperature range. The device itself operates from a separate 3.0 V to 5.5 V VCC supply, isolating logic and power domains. The 17 V headroom accommodates typical white or blue LED forward voltages in series configurations.

How does the TLC5923DAPG4 implement dot correction, and what is its resolution?

The TLC5923DAPG4 implements per-channel dot correction using a dedicated 7-bit register for each of its 16 outputs, providing 128 discrete current-level steps (0% to 100% of IMAX). Dot-correction data is loaded as a 112-bit serial packet (16 × 7 bits) when MODE = H and XLAT is held high. The internal current sink scales linearly with the programmed DC value, enabling precise compensation for LED forward-voltage and luminous-flux variations across manufacturing lots and temperatures.

What fault conditions trigger the XERR pin on the TLC5923DAPG4?

The XERR pin on the TLC5923DAPG4 is asserted low (open-drain) when either the LED Open Detection (LOD) circuit or Thermal Error Flag (TEF) circuit activates. LOD triggers when BLANK = L, the corresponding ON/OFF bit = 1, and the output voltage falls below 0.3 V (indicating an open LED). TEF triggers when the junction temperature exceeds ~160°C. Both faults share the same XERR output, requiring external logic or timing analysis to distinguish them - though LOD can be masked by setting BLANK = H.

Can multiple TLC5923DAPG4 ICs be cascaded, and how is data routed between them?

Yes, multiple TLC5923DAPG4 ICs can be cascaded using the SOUT pin of one device connected to the SIN pin of the next. In this configuration, a single 16-bit or 112-bit data packet is shifted through the entire chain: the first device receives bits intended for downstream units, retains its own portion, and forwards the remainder via SOUT. Cascading preserves timing integrity because XLAT and SCLK are shared across all devices, ensuring synchronized latching. The maximum practical cascade length depends on total clock period budget and system update rate requirements.

What is the role of the IREF pin on the TLC5923DAPG4, and how is output current calculated?

The IREF pin on the TLC5923DAPG4 connects to an internal 1.24 V bandgap reference. A single external resistor (R_IREF) between IREF and GND sets the maximum per-channel sink current using the formula: I_OUT(MAX) = 40 × (1.24 V / R_IREF). For example, a 1.24 kΩ resistor yields 40 mA per channel. R_IREF must be ≥600 Ω to limit I_REF current and prevent exceeding absolute maximum ratings. This architecture eliminates per-channel current-setting resistors and ensures matched accuracy across all 16 outputs.