Texas Instruments TLC6948DBQR

Overview

TLC6948DBQR from Texas Instruments is a 16-channel constant-current-sink LED driver IC optimized for high-multiplexing, fine-pitch LED matrix displays. It delivers 16-bit (65,536-step) grayscale PWM control per channel, supports up to 48-line multiplexing via integrated 24-Kbit SRAM, and operates with 0.3–25 mA per output across 3–5.5 V VCC. Its low-knee voltage (0.3 V @ 10 mA) enables efficient driving of low-Vf LEDs in high-density video panels.

For engineers reviewing the TLC6948DBQR datasheet, TLC6948DBQR pinout, TLC6948DBQR application, or TLC6948DBQR equivalent, key selection criteria include its dual-edge GCLK support (up to 25 MHz input → 50 MHz internal), LED-open detection (LOD) with serial readback, ±1% typical channel-to-channel current matching, and smart power-save mode (1 mA typical ICC).

Technical Context

The TLC6948DBQR implements two independent 16-bit × 16-channel × 48-line SRAM banks (BANK A/B) enabling seamless frame buffering-while one bank displays, the other accepts new grayscale data. Its enhanced spectrum PWM architecture eliminates low-grayscale coupling, ghosting, and caterpillar artifacts common in fine-pitch LED applications.

Grayscale timing is controlled by GCLK, configurable for single- or dual-edge operation via the GCLK_EDGE bit; dual-edge mode doubles effective PWM resolution without increasing clock frequency. Current regulation uses an external IREF resistor (1.02–10.7 kΩ) referenced to a stable 0.8 V internal voltage, with 7-bit global brightness control (BC) scaling all channels simultaneously.

Key Specifications

Pinout & Package

Package: DBQ - 24-pin SSOP (8.65 mm × 3.90 mm), leaded surface-mount package with standard gull-wing leads suitable for automated assembly and rework.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC6946DBQR and MAX7219CWG+, the TLC6948DBQR uniquely combines 48-line multiplexing, 16-bit grayscale, and hardware LOD in a single SSOP package-enabling higher panel resolution, smoother motion, and autonomous fault monitoring without added BOM cost or layout complexity.

Availability

TLC6948DBQR is available at Aetrix Electronics and suitable for high-refresh-rate LED video displays, fine-pitch rental screens, and outdoor digital signage requiring stable component supply and long-term production continuity.

Supply support for TLC6948DBQR 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 for industrial, automotive, and consumer markets.

The TLC6948DBQR belongs to TI's high-performance LED driver product line, engineered specifically for fine-pitch, high-multiplexing LED matrix applications demanding precision current matching, artifact-free grayscale, and robust diagnostics.

FAQ

What is the maximum multiplexing capability supported by the TLC6948DBQR?

The TLC6948DBQR supports up to 48-line multiplexing, enabled by its integrated 24-Kbit SRAM organized into two independent 16-channel banks. This allows one bank to display while the other receives new frame data-eliminating visible tearing and enabling high refresh rates in large LED panels. The TLC6948DBQR achieves this without external memory or host intervention, distinguishing it from lower-multiplexing alternatives like the TLC6946DBQR (32-line).

How does the TLC6948DBQR implement LED-open detection (LOD)?

The TLC6948DBQR monitors voltage at each OUTx pin during active drive periods and compares it against four user-selectable thresholds (0.12 V to 1.28 V). When an open-circuit condition is detected, the result is stored in an internal LOD register and can be read back via the serial interface (SIN/SOUT). This diagnostic capability is fully integrated-no external comparators or sense resistors are needed-and applies to all 16 channels independently.

Can the TLC6948DBQR operate with a 3.3 V supply and still deliver 25 mA per channel?

Yes, the TLC6948DBQR supports 3 V to 5.5 V VCC and maintains full 0.3–25 mA per-channel current range across that entire supply range. At 3.3 V, the maximum sink current remains 25 mA (typical) when using RIREF = 1.02 kΩ and BC = 7Eh. Its low 0.3 V knee voltage ensures minimal headroom loss, making it viable for 3.3 V systems driving standard red/green/blue LEDs.

What is the purpose of the dual-edge GCLK mode in the TLC6948DBQR?

Dual-edge GCLK mode allows the TLC6948DBQR to increment its internal grayscale counter on both rising and falling edges of the GCLK signal. This effectively doubles the PWM resolution without increasing the external clock frequency-e.g., a 25 MHz input yields 50 MHz internal timing-reducing EMI, simplifying clock distribution, and relaxing PCB layout constraints while preserving 16-bit grayscale fidelity.

Does the TLC6948DBQR require external components for basic operation?

Yes-the TLC6948DBQR requires an external resistor (RIREF) between Pin 23 (IREF) and GND to set the maximum output current, plus standard VCC decoupling capacitors (e.g., 100 nF ceramic + 4.7 µF tantalum near Pin 24). No external memory, level shifters, or current-sense circuitry is needed. All timing, grayscale, and diagnostics are handled internally, minimizing BOM count and board area.