Texas Instruments SN75DP128ARTQT

Overview

SN75DP128ARTQT from Texas Instruments is a DisplayPort 1:2 switch IC that routes one Dual-Mode DisplayPort input to either of two independent DisplayPort outputs, supporting data rates up to 2.7 Gbps per lane, 10.8 Gbps total throughput, and DisplayPort 1.1a compliance. It handles main link, AUX, HPD, and CAD switching for desktop PCs, notebooks, and docking stations.

For engineers reviewing the SN75DP128ARTQT datasheet, SN75DP128ARTQT pinout, SN75DP128ARTQT application, or SN75DP128ARTQT equivalent, key selection criteria include its 56-pin QFN package, dual-port HPD/CAD routing logic, DPVadj gain adjustment, ESD robustness (12 kV on main link), and commercial temperature range (0°C to 85°C).

Technical Context

The SN75DP128ARTQT implements a 2-to-1 MUX with priority-based port selection driven by HPD_A/HPD_B states and the Priority control pin. Its internal switching logic supports automatic failover, low-power state entry on dual HPD-low, and HPD/CAD signal repetition with programmable timing (tT1 = 2–4.7 ms, tT2 = 170–400 ms).

It replicates input waveform integrity across outputs using passive tracking architecture, with output amplitude adjustable via DPVadj resistor (6.49 kΩ nominal). The AUX channel operates in bidirectional differential mode (DisplayPort) or I²C mode (TMDS), dynamically optimized based on CAD pin status.

Key Specifications

Pinout & Package

SN75DP128ARTQT uses a 56-pin QFN (RTQT) package with exposed thermal pad. Pin functions are validated per TI SLLS940 datasheet, including 4×2 main link differential pairs (input + two output ports), dual AUX/HPD/CAD channels, and dedicated control pins (LP, Priority, DPVadj).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DisplayPort 1:2 switching applications.

Compared with PI3DPX1202ZLEX and TS3DV642RSBR, SN75DP128ARTQT offers native DisplayPort 1.1a switching with hardware-based HPD/CAD management and programmable gain-reducing firmware overhead and layout complexity in commercial PC and docking applications.

Availability

SN75DP128ARTQT is available at Aetrix Electronics and suitable for desktop PCs, notebook docking stations, and standalone graphics cards requiring stable component supply, long-term industrial availability, and guaranteed sourcing from authorized channels.

Supply support for SN75DP128ARTQT 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 broad industrial and computing market reach.

The SN75DP128ARTQT belongs to TI's DisplayPort interface product line, designed specifically for high-fidelity, low-latency video routing in commercial computing platforms without protocol stack intervention.

FAQ

What is the maximum data rate supported by the SN75DP128ARTQT?

The SN75DP128ARTQT supports data rates up to 2.7 Gbps per main link lane, compliant with DisplayPort 1.1a specifications. This enables full bandwidth for resolutions up to 2560×1600@60Hz across both output ports. Total aggregate throughput reaches 10.8 Gbps (4 lanes × 2.7 Gbps), verified under PRBS 2⁷−1 test patterns with ≤35 ps peak-to-peak residual jitter.

Does the SN75DP128ARTQT require external configuration or firmware control?

No, the SN75DP128ARTQT operates autonomously using hardware-based logic. Port selection is determined by HPD_A/HPD_B states and the Priority pin; low-power mode is controlled by the LP pin; and output gain is set via a resistor on DPVadj. No I²C, SPI, or microcontroller interface is needed-SN75DP128ARTQT functions as a transparent analog switch with built-in digital arbitration.

How does the SN75DP128ARTQT handle Hot Plug Detect (HPD) signal routing?

The SN75DP128ARTQT repeats HPD signals from either HPD_A or HPD_B to the upstream HPD output with precise timing: propagation delay tPD(HPD) is 30–110 ns, minimum pulse duration tM(HPD) is 100 ns, and unplug detection timeout tT2(HPD) is 170–400 ms. When both HPD inputs are high, the Priority pin selects the active port, and HPD output follows that port's state-enabling seamless hot-plug transitions without host intervention.

Can the SN75DP128ARTQT be used with HDMI or DVI sources via Dual-Mode DisplayPort?

Yes, the SN75DP128ARTQT supports Dual-Mode DisplayPort operation. Its AUX channel automatically configures as an I²C bus when CAD indicates TMDS mode (HDMI/DVI), allowing EDID communication and HDCP handshaking. Main link switching remains transparent-the SN75DP128ARTQT does not interpret video protocols, making it compatible with any source that complies with DisplayPort 1.1a's dual-mode specification.

What thermal considerations apply to the SN75DP128ARTQT in continuous operation?

The SN75DP128ARTQT has a junction-to-board thermal resistance (RθJB) of 11.03°C/W with 4×4 thermal vias under the exposed pad. At 340 mW typical power dissipation, board temperature rise is ~3.7°C above ambient. For reliable operation at 85°C ambient, maintain ≥4 thermal vias connected to solid ground planes and avoid enclosing the QFN package without airflow-TI specifies derated power of 1449 mW at TA = 85°C for low-K PCBs.