NXP Semiconductors PTN3381DBS,518

Overview

PTN3381DBS,518 from NXP Semiconductors is a fully integrated HDMI/DVI level shifter IC that converts four lanes of low-swing AC-coupled differential inputs (DisplayPort-compatible) to DVI v1.0/HDMI v1.4b-compliant TMDS outputs at up to 3 Gbit/s per lane, supports 36-bit deep color and 3D modes, includes an on-board 5 V regulator, and provides active DDC buffering with I²C-based dongle detection - deployed in DisplayPort-to-HDMI adapter dongles.

For engineers reviewing the PTN3381DBS,518 datasheet, PTN3381DBS,518 pinout, PTN3381DBS,518 application, or PTN3381DBS,518 equivalent, key selection considerations include TMDS lane speed compliance (3 Gbit/s), integrated 5 V regulator output capability (75 mA, ±300 mV), programmable equalizer settings (5 modes), back-current-safe sink-side terminals, and HDMI dongle detect via I²C slave ROM at address 81h.

Technical Context

The PTN3381DBS,518 implements transparent, non-re-timed level shifting across four high-speed differential lanes using self-biasing 50 Ω terminated inputs compliant with DisplayPort v1.2/PCIe v1.1 and open-drain current-steering outputs compliant with DVI v1.0/HDMI v1.4b. Its DDC channel uses active bidirectional I²C buffering with rise time acceleration on sink-side SCL/SDA to support up to 18 m cable length or 1400 pF bus capacitance.

It integrates a 5 V DC regulator powered from 3.3 V VDD, delivering up to 75 mA with short-circuit and overcurrent protection; HPD level shifting is non-inverting (0–5 V sink → 0–3.3 V source) with internal 200 kΩ pull-down; all sink-side interfaces (TMDS, DDC, HPD) feature back-drive protection to prevent current flow when unpowered.

Key Specifications

Pinout & Package

HVQFN48 package (7 mm × 7 mm × 0.85 mm), thermally enhanced with exposed center pad requiring PCB thermal vias and solder connection to GND. All 48 pins are defined per NXP datasheet Rev. 2 (26 July 2012).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar HDMI/DVI level shifting applications.

Compared with PTN3361D, PTN3381DBS,518 reduces system BOM and layout complexity via integrated regulation; compared with PTN3381B, it delivers higher bandwidth and design flexibility through programmable equalization - making it the optimal choice for next-generation DisplayPort adapter dongles.

Availability

PTN3381DBS,518 is available at Aetrix Electronics and suitable for DisplayPort-to-HDMI adapters, DisplayPort-to-DVI adapters, HDMI dongle detection systems, DDC bus extension modules, and industrial video interface designs requiring stable component supply and long-term lifecycle support.

Supply support for PTN3381DBS,518 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer applications.

The PTN3381DBS,518 belongs to NXP's Display Interface portfolio, designed specifically to simplify high-speed video interface bridging in compact adapter and dongle form factors while meeting HDMI, DVI, and DisplayPort interoperability requirements.

FAQ

What is the maximum data rate supported by PTN3381DBS,518 per TMDS lane?

The PTN3381DBS,518 supports up to 3 Gbit/s per TMDS lane, enabling HDMI v1.4b features including 36-bit deep color, stereoscopic 3D, and 3 Gbit/s operation. This corresponds to a 300 MHz character clock and is validated per HDMI v1.4b and DVI v1.0 electrical specifications. The device achieves this using self-biasing differential inputs and open-drain current-steering outputs with integrated 50 Ω termination.

Does PTN3381DBS,518 require external termination resistors on its TMDS inputs?

No, PTN3381DBS,518 does not require external termination resistors on its TMDS inputs. It integrates 50 Ω self-biasing termination internally for all four differential input pairs (IN_D1± through IN_D4±). External AC coupling capacitors are still required per lane, but no external resistors are needed for input termination - simplifying layout and improving signal integrity consistency.

How is HDMI dongle detection implemented in PTN3381DBS,518?

PTN3381DBS,518 implements HDMI dongle detection via an on-board I²C slave ROM that responds to a Read command at address 81h with a fixed 16-byte ASCII sequence "DP-HDMI ADAPTOR". This function is enabled only when the DDET pin is tied HIGH; when DDET is LOW, the device ignores I²C read commands. The feature complies with DisplayPort interoperability guidelines for HDMI adapter identification.

What protection features does PTN3381DBS,518 provide for sink-side interfaces?

PTN3381DBS,518 provides back-current-safe design on all sink-side interfaces: TMDS outputs (OUT_Dx), DDC I/Os (SCL_SINK/SDA_SINK), and HPD_SINK. When the device is unpowered, these terminals sink only negligible leakage current and block reverse current flow from a powered display into the source side or power supply - preventing damage and ensuring safe hot-plug operation in real-world adapter use cases.

Can PTN3381DBS,518 operate without the integrated 5 V regulator enabled?

Yes, PTN3381DBS,518 can operate without using the integrated 5 V regulator. The core level-shifting functionality (TMDS, DDC, HPD) runs from the 3.3 V VDD supply alone. The V5OUT regulator activates automatically when valid 3.3 V is applied to VDD pins, but if the HDMI/DVI connector's 5 V is supplied externally, V5OUT may be left unconnected. CP and CN pins must still be decoupled per datasheet recommendations even if V5OUT is unused.