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Texas Instruments TLC5955RTQR
- Part No.:
- TLC5955RTQR
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 56-VFQFN Exposed Pad
- Datasheet:
-
TLC5955RTQR.pdf
- Description:
- IC LED DRV LIN 23.9/31.9MA 56QFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,401
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Product details
Overview
TLC5955RTQR from Texas Instruments is a 48-channel, 16-bit PWM constant-current LED sink driver with integrated dot correction (DC), global brightness control (BC), and LED open/short detection. It delivers up to 31.9 mA per channel at VCC > 3.6 V, supports 65,536-step grayscale, 128-step DC/BC, and operates across –40°C to +85°C for high-reliability LED video displays.
For engineers reviewing the TLC5955RTQR datasheet, TLC5955RTQR pinout, TLC5955RTQR application, or TLC5955RTQR equivalent, key selection criteria include its QFN-56 package, 33 MHz GSCLK timing, 25 MHz SCLK data rate, integrated current-setting architecture (no external resistor), and dual error-detection capability for field-deployed signage systems.
Technical Context
The TLC5955RTQR implements a hierarchical PWM architecture: a 16-bit grayscale counter driven by GSCLK controls on-time per channel, while 7-bit DC and BC registers scale output current multiplicatively per channel and per color group respectively. Its 769-bit serial interface accepts command/data packets differentiated by MSB and header bits.
It integrates three independent latches-768-bit GS, 336-bit DC, and 371-bit control (MC/BC/FC/LOD/LSD)-with auto-refresh for GS/DC data and display timing reset synchronization. LED fault detection (LOD/LSD) status is read back via SOUT after LAT assertion, enabling real-time panel diagnostics without interrupting display operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output channels | 48 constant-current sink outputs (16 red, 16 green, 16 blue) |
| Grayscale resolution | 16-bit (65,536 steps); enables smooth dimming and fine color gradation in RGB displays |
| Max sink current | 31.9 mA per channel at VCC > 3.6 V; supports high-brightness LEDs without external current boost |
| Dot correction | 7-bit (128 steps) per channel; corrects channel-to-channel intensity variation to improve display uniformity |
| Data clock rate | 25 MHz SCLK; enables fast frame loading for large panels (e.g., 1920×1080 with multiplexing) |
| GS clock frequency | 33 MHz GSCLK; ensures precise 16-bit PWM timing with <±20 ns on-time error |
| LED fault detection | Dual LOD/LSD reporting via SOUT; allows automated failure mapping in outdoor VMS without manual inspection |
Pinout & Package
Package: QFN-56 (8.0 mm × 8.0 mm, 0.5 mm pitch) with exposed thermal pad requiring PCB GND connection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SIN | Serial input | Accepts 769-bit shift register data; MSB determines latch destination (GS vs control) |
| SCLK | Shift clock | Drives data into shift register on rising edge; max 25 MHz supports high-throughput panel updates |
| LAT | Latch enable | Rising edge transfers data to GS or control latch; triggers display timing reset when TMGRST=1 |
| GSCLK | Grayscale clock | Drives 16-bit PWM counter; rising edge resets counter when TMGRST enabled |
| SOUT | Serial output | Shifts out status data (LOD/LSD flags) or next-bit data; enables daisy-chained configuration |
| OUTR0–OUTR15 | Red channel sinks | 16 dedicated constant-current outputs; each configurable independently for R-color group |
| OUTG0–OUTG15 | Green channel sinks | 16 dedicated constant-current outputs; paired with red/blue for full RGB pixel control |
| OUTB0–OUTB15 | Blue channel sinks | 16 dedicated constant-current outputs; completes 48-channel RGB LED drive capability |
| VCC | Power supply | 3.0–5.5 V logic and analog supply; powers internal reference and shift logic |
| GND | Ground | Multiple pins (8, 35) ensure low-impedance return path; thermal pad must be soldered to GND plane |
Key Features
| Feature | Design Value |
|---|---|
| Internal current setting | 3-bit MC control selects 8 max-current ranges (3–30 mA); eliminates external resistor failure modes and layout sensitivity |
| Auto data refresh | GS and DC data automatically refreshed during display idle time; maintains stable output without host intervention |
| Delay switching | Controlled turn-on sequencing prevents inrush current spikes during power-up or mode transitions |
| UVLO default | Undervoltage lockout initializes all registers to safe state (e.g., outputs off, BC=10%) on power ramp |
| Knee voltage | 0.25 V typical dropout; enables efficient operation with low-Vf LEDs and reduces system power dissipation |
Applications
| LED Video Displays | Variable Message Signs (VMS) |
|---|---|
Use Scenario: Indoor full-color LED wall with 10-mm pitch and 1920×1080 resolution. IC Role / Device Role / Timing Role: Primary RGB LED driver controlling 48 discrete pixels per IC; synchronized via GSCLK and LAT to eliminate flicker. Use Value: 16-bit grayscale and per-channel DC correction ensure uniform luminance and accurate color reproduction across 10,000+ pixels. | Use Scenario: Highway-facing roadside sign with 300-mm character height and solar-powered operation. IC Role / Device Role / Timing Role: Constant-current sink managing red/green/blue segments per character; LOD/LSD reports failed LEDs to central controller. Use Value: Integrated fault detection reduces maintenance visits; low knee voltage extends battery runtime under variable load conditions. |
| Illumination Systems | Stage Lighting Arrays |
Use Scenario: Architectural cove lighting with tunable white (CCT 2700K–6500K) and RGB accent zones. IC Role / Device Role / Timing Role: Precision current source for mixed-color LED strings; BC adjusts white point, DC trims binning variation. Use Value: 7-bit BC per color group enables stable white balance over temperature; 128-step DC compensates for LED aging drift. | Use Scenario: DMX-controlled moving head fixture with 24 RGBW modules per head. IC Role / Device Role / Timing Role: High-speed PWM driver receiving SPI-like serial commands; GSCLK synchronized to master timing generator. Use Value: 33 MHz GSCLK supports 120 Hz refresh with zero visible PWM artifacts; SOUT daisy-chain simplifies wiring in compact fixtures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLC5947RTQT | 48-channel, 12-bit grayscale, no integrated LOD/LSD; requires external current-setting resistors | Lacks fault detection and auto-refresh; suited for cost-sensitive indoor signage without remote diagnostics | Select when lower BOM cost and simpler layout outweigh need for real-time LED health monitoring |
| IS31FL3731-QFLS4 | 28-channel, 8×4 matrix, I²C interface, built-in breathing effects; max 40 mA but only 28 outputs | Matrix architecture limits per-pixel control; I²C simplifies host interface but lacks high-speed serial throughput | Select for embedded UI lighting with animation features where channel count and serial speed are secondary |
Compared with TLC5955RTQR, TLC5947RTQT offers lower integration and no fault reporting, while IS31FL3731-QFLS4 trades channel density and serial bandwidth for ease of I²C integration and on-chip effects-neither matches TLC5955RTQR's combination of 48-channel precision, 16-bit PWM, and diagnostic capability in a single QFN package.
Availability
TLC5955RTQR is available at Aetrix Electronics and suitable for LED video displays, variable message signs (VMS), and architectural illumination requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for TLC5955RTQR 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 ICs for industrial, automotive, and communications markets.
The TLC5955RTQR belongs to TI's high-performance LED driver product line, engineered specifically for large-format, high-resolution RGB displays demanding precise current matching, real-time fault visibility, and robust operation in ambient temperatures from –40°C to +85°C.
FAQ
What is the maximum output current per channel for TLC5955RTQR at 5.0 V VCC?
The TLC5955RTQR delivers up to 31.9 mA per channel when VCC exceeds 3.6 V and maximum current (MC) control is set to code 7. This value is measured at VOUT = 0.8 V and TA = +25°C, with ±4% device-to-device accuracy ensuring consistent brightness across multiple TLC5955RTQR units in a single display system.
How does the TLC5955RTQR implement LED open and short detection?
The TLC5955RTQR performs LED open detection (LOD) by measuring voltage at each OUTXn pin during off-time; a reading above 0.35 V indicates an open circuit. LED short detection (LSD) compares output voltage against programmable thresholds (0.7×VCC or 0.9×VCC) during on-time. Detection results for all 48 channels are reported serially via SOUT after LAT assertion, enabling rapid panel-level diagnostics without halting display operation.
Can TLC5955RTQR be used in daisy-chained configurations?
Yes, the TLC5955RTQR supports daisy-chaining via its SIN and SOUT pins. Serial data flows from SIN of the first device to SOUT of the previous one, allowing cascaded control of multiple TLC5955RTQR ICs with a single host interface. The 769-bit shift register accommodates full configuration of one device, and latency between devices is deterministic based on SCLK frequency and chain length.
What is the function of the thermal pad on the TLC5955RTQR QFN package?
The exposed thermal pad on the TLC5955RTQR QFN-56 package must be soldered to a PCB ground plane to ensure proper thermal dissipation. It is not internally connected to GND, so direct soldering to a solid copper pour tied to system GND is required. This connection reduces junction-to-board thermal resistance to 6.4°C/W, critical for maintaining ≤125°C junction temperature under full 48-channel 31.9 mA operation.
Does TLC5955RTQR require external resistors for current setting?
No, the TLC5955RTQR uses internal current-setting architecture controlled by 3-bit maximum current (MC) data, eliminating the need for external resistors. This removes resistor tolerance errors, temperature drift, and PCB layout sensitivity-improving channel-to-channel current matching to ±2% typical and enhancing long-term reliability in field-deployed LED systems.
TLC5955RTQR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 56-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Linear
- Topology:
- Shift Register
- Internal Switch(s):
- Yes
- Number of Outputs:
- 48
- Voltage - Supply (Min):
- 3V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 10V
- Current - Output / Channel:
- 23.9mA, 31.9mA
- Frequency:
- -
- Dimming:
- -
- Applications:
- Signage
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 56-QFN (8x8)
TLC5955RTQR FAQ
1.How can I place an order for TLC5955RTQR through Aetrix?
Please submit a Request for Quotation (RFQ) for TLC5955RTQR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TLC5955RTQR reliable?
The price and inventory of TLC5955RTQR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLC5955RTQR is usually 5 days.
3.What payment methods are accepted for TLC5955RTQR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLC5955RTQR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLC5955RTQR?
TLC5955RTQR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLC5955RTQR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TLC5955RTQR?
For technical support, including TLC5955RTQR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLC5955RTQR requirements.
6.How does Aetrix verify that TLC5955RTQR is sourced from the original manufacturer or authorized distributors?
All TLC5955RTQR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TLC5955RTQR meets industry standards.
7.What is the process for return or replacement of TLC5955RTQR?
All TLC5955RTQR units undergo pre-shipment inspection (PSI). If there is an issue with TLC5955RTQR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TLC5955RTQR part is unused and in its original packaging.
Return procedure for TLC5955RTQR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLC5955RTQR Tags
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