Early Silicon Image DVI Transmitter and Receiver Chips

Silicon Image played a foundational role in the transition from analog VGA to digital displays during the late 1990s and early 2000s. By developing PanelLink technology—the proprietary serialization method that formed the core of Transition Minimized Differential Signaling (TMDS) and the DVI 1.0 specification—the company produced the industry's first discrete DVI transmitter and receiver chips. This article covers the primary standalone transmitters (such as the SiI 154 and SiI 164) and receivers (such as the SiI 151 and SiI 161) that enabled early digital video transmission before graphics processors and monitor scalers integrated these interfaces directly.

The Role of Discrete DVI Chips

When the Digital Display Working Group (DDWG) standardized DVI in 1999, graphics processing units (GPUs) and monitor display controllers lacked built-in digital serialization hardware. Graphics cards output parallel digital RGB signals, while flat-panel displays required parallel data to drive LCD columns. Silicon Image filled this hardware gap by offering discrete transmitters to convert parallel GPU signals into high-speed TMDS serial streams, and discrete receivers to reconstruct the parallel data inside monitors.

Early Standalone DVI Transmitters (Tx)

Silicon Image's standalone transmitters were commonly surface-mounted onto PCI and AGP graphics cards, as well as digital daughtercards (such as ADD/ADD2 cards for motherboards with integrated graphics).

  • SiI 154: One of the earliest DVI-compliant single-link transmitters. It supported pixel clock rates up to 112 MHz, enabling resolutions up to SXGA (1280 × 1024) at 60 Hz. It converted a 24-bit parallel RGB bus into three differential TMDS data lanes and one clock lane.
  • SiI 164: The most widespread single-link DVI 1.0 transmitter of its era. The SiI 164 raised the maximum pixel clock frequency to the full DVI standard limit of 165 MHz, enabling UXGA (1600 × 1200) and 1080p resolutions at 60 Hz. It featured programmable drive strengths to compensate for board trace and cable attenuation, an integrated phase-locked loop (PLL), and operated on low-voltage 3.3V logic. It was standard equipment on many ATI Radeon and early NVIDIA GeForce cards.
  • SiI 160: A variant optimized for mobile and low-power applications, primarily deployed in high-end laptops and compact form-factor systems.
  • SiI 170: A dual-link TMDS transmitter designed for very high-resolution displays. By incorporating two TMDS links operating in parallel, the SiI 170 provided clock bandwidth beyond 165 MHz, allowing systems to drive early ultra-high-resolution monitors (such as QXGA at 2048 × 1536).

Early Standalone DVI Receivers (Rx)

On the display side, CRT replacements and early LCD panels used Silicon Image receivers to decode incoming TMDS signals into parallel digital streams for scaler chips and timing controllers (TCONs).

  • SiI 151 / SiI 151B: The receiver counterpart to the SiI 154. It recovered pixel clocks up to 112 MHz from the differential TMDS inputs, reconstructed 24-bit true color parallel RGB, and included inter-pair de-skewing circuitry to handle differing transmission delays across wire pairs.
  • SiI 161 / SiI 161B: The direct companion to the SiI 164 transmitter, capable of receiving clock rates from 25 MHz up to 165 MHz. It featured advanced clock and data recovery (CDR) architectures to stabilize jittery inputs over long DVI cables, providing robust SXGA and UXGA display outputs.
  • SiI 163B: An updated, low-noise receiver featuring power-management controls, enhanced electromagnetic interference (EMI) reduction techniques, and dual-edge clocking support to reduce the bus frequency between the receiver and downstream LCD controller.

Market Transition to Integration

These standalone chips dominated display designs from approximately 1999 to 2004. As manufacturing processes shrunk, GPU makers (ATI, NVIDIA, Intel) integrated TMDS encoders directly into display output blocks, and monitor controller vendors (such as Genesis Microchip, Pixelworks, and Realtek) integrated TMDS receivers directly into monitor scaler SoCs. While discrete chips eventually fell out of favor for standard consumer PC applications, Silicon Image's early SiI components established the hardware foundation for both modern DVI and its successor, HDMI.