Texas Instruments TLC5928PW

Overview

TLC5928PW from Texas Instruments is a 16-channel constant-current LED sink driver in TSSOP-24 package, delivering up to 35 mA per channel with ±1% channel-to-channel current accuracy, 35-MHz serial data rate, and integrated LED open detection (LOD) and pre-thermal warning (PTW). It operates from 3.0 V to 5.5 V VCC and supports LED power-supply voltages up to 17 V, enabling use in high-brightness outdoor signage and industrial panel displays.

For engineers reviewing the TLC5928PW datasheet, TLC5928PW pinout, TLC5928PW application, or TLC5928PW equivalent, key selection criteria include its 20-ns BLANK pulse width, 10-ns output transient time, readable error status via SOUT, IREF-based current programming, and daisy-chain capability for multi-device systems.

Technical Context

The TLC5928PW implements a 16-bit serial shift register followed by a parallel latch for on/off control of all 16 constant-current sinks. Its LOD circuit monitors each OUTn voltage during active sinking (VOUTn ≤ 0.30 V triggers detection), while PTW activates at junction temperature ≥ +138 °C (typ).

Control timing relies on three critical inputs: SCLK (35 MHz max), LAT (edge-triggered latch enable), and BLANK (global output enable with 20-ns minimum low pulse width). Error data (LOD/PTW) are captured on BLANK rising edge and shifted out via SOUT synchronized to SCLK.

Key Specifications

Pinout & Package

TLC5928PW uses a 24-pin TSSOP package (4.4 mm × 7.8 mm, 0.65 mm pitch) with 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 LED driver applications.

Compared with TLC5928PW, TLC5940PWPR adds grayscale control at the cost of increased complexity and non-interchangeable firmware, while MAX7219CWG+ reduces channel count and omits fault diagnostics-making TLC5928PW optimal for cost-sensitive, high-reliability 16-channel LED sink applications requiring embedded health monitoring.

Availability

TLC5928PW is available at Aetrix Electronics and suitable for LED video displays, message boards, and industrial control panels requiring stable component supply, long-term production continuity, and guaranteed traceable sourcing.

Supply support for TLC5928PW 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 connectivity solutions, with decades of experience in precision power and signal chain ICs.

The TLC5928 product line was designed specifically for high-reliability LED driving in commercial and industrial signage, emphasizing fault resilience (LOD/PTW), timing precision, and ease of system integration via daisy-chain serial control.

FAQ

What is the maximum LED supply voltage supported by the TLC5928PW?

The TLC5928PW supports LED power-supply voltages up to 17 V at its OUT0–OUT15 pins. This allows direct connection to common 12 V or 24 V LED string supplies without intermediate regulation, provided the voltage difference between VCC and the LED rail remains within absolute maximum ratings. The device's output stage is rated for –0.3 V to +18 V, ensuring robust operation under transient conditions.

How does the TLC5928PW implement LED open detection (LOD)?

The TLC5928PW performs LED open detection by monitoring the voltage at each OUTn pin while the channel is actively sinking current. If VOUTn drops to ≤0.30 V (typical threshold), the corresponding LOD bit is set to '1' in the Status Information Data (SID) register. This detection occurs only when BLANK is low and the output is enabled, and valid status is latched on the rising edge of BLANK for subsequent readback via SOUT.

Can multiple TLC5928PW devices be daisy-chained, and how is data routed?

Yes, multiple TLC5928PW devices can be daisy-chained using a single serial bus. The SOUT pin of one device connects to the SIN pin of the next. Data written to the first device's SIN propagates through the chain: 16 bits fill the first device's shift register, the next 16 bits go to the second, and so on. LAT and BLANK remain common across all devices, enabling synchronized latching and blanking across the entire chain.

What is the role of the IREF pin on the TLC5928PW, and how is current set?

The IREF pin on the TLC5928PW connects to an external resistor (RIREF) tied to GND, establishing the reference for all 16 constant-current sinks. An internal 1.20 V bandgap reference develops across RIREF, yielding output current IOUT = 42 × (1.20 V / RIREF). For example, a 1.44 kΩ resistor sets IOUT ≈ 35 mA. The resistor value must be selected to keep IOUT within 2–35 mA per channel.

Does the TLC5928PW provide thermal protection, and how is it signaled?

The TLC5928PW includes pre-thermal warning (PTW) functionality-not full thermal shutdown-but signals when junction temperature reaches +138 °C (typical). When triggered, the PTW bit in the SID register goes high, and all 16 LOD bits are forced to '1' on the next BLANK rising edge. This flag is readable via SOUT and allows the host controller to proactively reduce duty cycle or disable affected channels before thermal damage occurs.