Chip sets support 10.3-Gbps Thunderbolt-interface standard

Bill Schweber, EE Times - May 10, 2012

If you’re unfamiliar with Thunderbolt technology, you probably should get started. Intel developed the technology, which it markets with Apple. It enables fast data transfers between a PC and a peripheral or a display device, combining PCIe and DisplayPort technology for simultaneous bidirectional transfers at 10.3 Gbps over a single cable.

Such speed comes at a price, however. In addition to the Intel-supplied host processor, graphics-processing unit, and platform-controller hub, the technology requires some dedicated interface management, support components, and carefully built cable using 40-gauge AWG to make it happen. It also demands a significant amount of power and management.

A sextet of ICs from Texas Instruments strives to achieve these goals. The family includes the TPS22980 power-load switch, which resides on both the host and the device side, facilitating the delivery and receipt of power to both the active cable and the connected device. You’ll also find the LM3017 boost-and-battery disconnect and HD3SS001 FET switch, which work in tandem on the host to connect to the cable. The TPS22985 power-load switch, DS100TB211 signal-conditioning retimer with clock and data recovery, and LMZ10501 Simple Switcher nanomodule reside at the cable. Prices for the components range from 65 cents to $3.95 (1000).

Chip sets support 10.3-Gbps Thunderbolt-interface standard image

The 3.3 to 18V TPS22980 power-load switch saves board space and simplifies system design by providing a dual-voltage switch with an adjustable current limit that prevents damage to the connected device. It includes high-voltage discharge before low-voltage connection to protect components from overvoltage exposure. The device comes in a 4×4-mm QFN package and sells for $1.10 (1000). The TPS22985 power-selection device manages all power delivery through a Thunderbolt-technology cable, simplifying cable designs. Targeting use with the DS100TB211 for cable implementation, the device minimizes the need for external circuitry and saves space in the active-cable form factor. Measuring 1.6×1.6 mm, the device sells for 65 cents.

The dual-lane DS100TB211 signal-conditioning retimer with clock and data recovery has adaptive four-stage equalization, which enables the use of thin, inexpensive, 40-gauge AWG cable. It also integrates clock synthesis and power filtering, reducing bill-of-materials cost and the number of necessary PCB layers. On-chip cable diagnostics lower assembly time and cost. In a 5×5-mm QFN package, the device sells for $3.95. The HD3SS0001 data-source-selection switch integrates multiple discrete components, saving board space. Its pinout optimizes routing from signal sources to the connector. The device comes in 3.5×5.5-mm TQFN package and sells for 90 cents.

The LM3017 boost controller features true shutdown, which protects the battery from excessive current draw in a short-circuit condition. It meets both broadband-output-noise and ripple requirements with less than 50 mV p-p. The device features output power of as much as 30W for driving two Thunderbolt ports at 15W each and a ±1% reference voltage, which provides accurate output to the power load switch. Available in a 2.4×2.7-mm QFN package, the device sells for 97 cents.

The 1A LMZ10501 Simple Switcher nanomodule integrates an inductor, saving board space and easing design. It features efficiency as high as 97%, reducing system-heat generation, and has an adjustable output voltage, providing design flexibility. The 3×2.5-mm SE08A-packaged device sells for $1.80.

Texas Instruments