Texas Instruments TLC5945PWPR

Overview

TLC5945PWPR from Texas Instruments is a 16-channel constant-current LED driver IC with integrated 12-bit grayscale PWM control (4096 steps) and 6-bit dot correction (64 steps), supporting up to 80 mA per channel and LED supply voltage up to 17 V. It operates from 3.0 V to 5.5 V and features LED open detection (LOD), thermal error flag (TEF), and serial interface with 30-MHz SCLK capability for high-resolution LED signage and display backlighting.

For engineers reviewing the TLC5945PWPR datasheet, TLC5945PWPR pinout, TLC5945PWPR application, or TLC5945PWPR equivalent, key selection criteria include its 16-channel sink architecture, external IREF resistor-based current setting, dual-mode serial programming (GS/DC), open-drain XERR error reporting, and HTSSOP-28 PowerPAD™ thermal package compatibility.

Technical Context

The TLC5945PWPR implements independent grayscale and dot correction registers accessed via a 3-wire serial interface (SIN/SCLK/XLAT), where MODE selects between 192-bit grayscale data loading (MODE = GND) and 96-bit dot correction data loading (MODE = VCC). Grayscale operation uses an internal 12-bit counter synchronized to GSCLK, while dot correction adjusts per-channel current scaling prior to PWM modulation.

It integrates two error-detection circuits: LOD monitors output voltage drop (<0.3 V typical) during active sink periods to detect open LEDs, and TEF triggers at ~160°C junction temperature. Both flags drive the open-drain XERR pin, and LOD status bits (16) plus TEF (1 bit) are readable via SOUT in grayscale mode after XLAT latching.

Key Specifications

Pinout & Package

Package: 28-pin HTSSOP PowerPAD™ (PWP), thermally enhanced with exposed copper pad soldered to PCB ground plane for improved heat dissipation (θ_JA = 31.58°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC5945PWPR, TLC5947RTQR offers expanded channel count and current headroom at the cost of package incompatibility, while MAX6966ATL+ trades grayscale resolution and speed for interface simplicity and smaller footprint - both require PCB redesign and firmware adaptation.

Availability

TLC5945PWPR is available at Aetrix Electronics and suitable for LED signage, full-color video walls, and display backlighting requiring stable component supply, consistent thermal performance, and long-term manufacturing continuity.

Supply support for TLC5945PWPR 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 LED driver innovation.

The TLC5945 product line delivers high-precision, thermally robust LED current control for professional-grade visual displays - designed specifically for applications demanding uniform brightness, fault resilience, and scalable channel density.

FAQ

What is the maximum output current per channel for the TLC5945PWPR?

The TLC5945PWPR supports a maximum constant-current sink of 80 mA per channel (OUT0–OUT15), set by an external resistor on the IREF pin. The relationship is Imax = 31.5 × (1.24 V / R_IREF). For example, a 640 Ω resistor yields ~61 mA typical, verified across –40°C to 85°C ambient. Current stability is maintained within ±4% channel-to-channel error under specified conditions.

How does the TLC5945PWPR handle LED open-circuit faults?

The TLC5945PWPR detects open LEDs via its LED Open Detection (LOD) circuit, which monitors each OUTn voltage during active sink periods. If voltage remains below 0.3 V (typical) when current is enabled, LOD asserts and pulls the open-drain XERR pin low. LOD status bits (16) are also latched into the status register and readable via SOUT after XLAT in grayscale mode.

Can the TLC5945PWPR be used without an external GSCLK source?

No - the TLC5945PWPR requires an external GSCLK signal to drive its 12-bit grayscale counter; it has no internal oscillator. GSCLK frequency directly determines PWM update rate (e.g., 1 MHz GSCLK yields ~244 Hz frame rate). The device supports GSCLK frequencies up to 30 MHz, and the clock must be stable and free of jitter to prevent grayscale timing errors in the TLC5945PWPR.

What is the role of the MODE pin on the TLC5945PWPR?

The MODE pin configures the TLC5945PWPR's serial interface width and register target: MODE = GND selects 192-bit grayscale (GS) mode, loading data into the 12-bit per-channel GS register; MODE = VCC selects 96-bit dot correction (DC) mode, loading data into the 6-bit per-channel DC register. XLAT latches data only when MODE is stable; transitions during XLAT high may corrupt the TLC5945PWPR register state.

Is the TLC5945PWPR compatible with 3.3 V microcontrollers?

Yes - the TLC5945PWPR supports VCC from 3.0 V to 5.5 V and uses CMOS-level I/O. All inputs (SIN, SCLK, XLAT, BLANK, MODE, GSCLK) accept VIH ≥ 0.8×VCC and VIL ≤ 0.2×VCC, making it fully interoperable with 3.3 V logic systems. Outputs (SOUT, XERR) are compatible with 3.3 V receivers when properly pulled up, and OUTn sink capability is unaffected by VCC within spec.