Track-and-hold amps boast ultrawide bandwidth

Inphi is claiming a new industry standard with the launch of its GigaTrack family of 2Gsample/s track-and-hold amplifiers that deliver ultrawide 18GHz analogue bandwidth.

Inphi is claiming a new industry standard with the launch of its GigaTrack family of 2Gsample/s track-and-hold amplifiers (THA) that deliver ultrawide 18GHz analogue bandwidth.

The combined bandwidth, sample rate and linearity of these track-and-holds make possible direct conversion and software-defined receivers, and will also advance the state of the art in high sample rate test and measurement equipment.

The GigaTrack track and holds operate from a single -5.2V power supply and dissipate only 1.3W.

They are available in a 49-pin ceramic ball-grid array and in 24-pin QFN packages.

"Inphi has built its reputation on creating and delivering best-in-class devices and we're doing it again with the introduction of the GigaTrack family of devices", said Kevin Nary, Vice President of Engineering at Inphi.

"GigaTrack track and holds will enable an entirely new class of instrumentation, communications, ATE, and military systems".

"In addition to providing the highest performance available, the low power dissipation and sise of these devices will result in digital receivers and data acquisition systems that are themselves low power and compact".

These unparalleled parts are specifically designed to meet the needs of engineers designing next generation instrumentation, ATE, and military equipment.

Fast sampling oscilloscopes, direct conversion receivers in radios, radar or electronic warfare systems, all demand wider-bandwidth and higher sample rate analogue-to-digital conversion.

With the GigaTrack THAs, engineers can for the first time replace numerous components in traditional heterodyne receiver architectures with a track-and-hold and a high sample rate ADC.

The resulting receivers are lower power and more compact than traditional heterodyne receivers, and they provide far more flexibility.

Signal processing (ie down-conversion or channelising) that was "hard-wired" in heterodyne receivers, can now be performed digitally and can be "software defined".

A direct conversion receiver can serve multiple applications with system differentiation occurring in software or firmware.

The new GigaTrack family consists of four track-and-hold amplifiers with 2Gsample/s sample rates.

The ball-grid-array versions offer 18GHz (small signal) and 15GHz (0.5V peak-peak) input analogue bandwidths with very fast settling times (up to 60ps) and low power consumption (1.3W).

Plastic QFN versions provide 13GHz analogue bandwidth (100mV peak-peak).

In order to deliver a wider hold time window for the downstream ADC, a master/slave (dual) track-and-hold architecture was developed.

This provides higher accuracy in the digitisation process by increasing the hold time window to almost one full cycle of the THA.

For users who want to subsample the output of the master track-and-hold with the slave track and hold, the 1821TH and lower performance 1321TH devices provide a flexible clock mode select pin which, in one mode, allows the user to provide different clocks to the master and slave track and holds.

The GigaTrack family's best-in-class settling time (better than 60ps) maximises timing margin to improve accuracy and performance, while the best-in-class total harmonic distortion (-70dB typical at 1GHz and 500mV peak-peak input) and aperture jitter (less than 50fs) support improved ADC signal-to-noise-and-distortion ratios leading to more sensitive and accurate acquisition systems.

Also, by eliminating the requirement for two separate power supply voltages, these track-and-hold THA devices simplify board layout, lowers system cost, and helps reduce power consumption by up to 20%.

The GigaTrack family supports all popular, broadband analogue-to-digital ADC devices including National Semiconductor ADC08100/81500, Atmel AT84AS003/008, ADI 9480, Maxim/Dallas MAX104/108, and others.

The 1820TH and 1821TH are both supported in 49-pin 6mm BGA packages with evaluation kits now available for performance testing.

The 1821TH is also offered in die form.

The 1820TH and 1821TH with clock mode select are priced at $489 and $549, respectively, in 1000-unit quantities.

The lower bandwidth 1320TH and 1321TH are supported in 24-pin 4mm QFN packages priced at $329 and $379, respectively, in 1000-unit quantities.

Radiation hardened versions of the GigaTrack products will be available later this year.

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