100MSPS

The AL1210 is an extremely fast and accurate monolithic track and hold amplifier. Even at input frequencies of up to 20MHz, and sampling rates of 50MSPS, its outstanding performance allows full 12-bit linearity to be maintained. Under
these extremely fast conditions, the TOTAL harmonic distortion introduced by the AL1210 is still only -70dBc.

Its primary application is as a track and hold with the new generation high speed flash A/D converters. By using the AL1210 with these converters, it is now possible to obtain meaningful 10-bit performance at input frequencies of up to 40MHz and sampling rates of up to 75MSPS. If the AL1210 were not used, the meaningful resolution would drop down to 6 bits or less. At 50MHz the TOTAL harmonic distortion is only -59dBc.

The noise that a track and hold circuit generates must be significantly below the resolution or noise of the A/D converter in order not to limit the dynamic range of the system. The causes of noise in a track and hold are quite complex and come from several sources. In the AL1210 these noise sources are kept very low, for example, an aperture jitter of only 1ps and a total output noise of only 50 V.

To obtain this remarkable performance, innovative circuit design and careful layout have been used. It is fabricated in a very fast complementary bipolar process. The AL1210 is packaged in a 16-pin SOIC in order to keep the pin inductances and capacitances to a minimum.