Linear Technology Corp.'s LT1993 is a family of high-speed fully differential amplifiers for driving high-resolution, high-speed analog-to-digital converters (ADCs). With fixed-gain options of 2 (6dB), 4 (12dB) and 10 (20dB) and a built-in user-adjustable filter, the LT1993 enables designers to directly drive ADCs and achieve optimal performance without using complex support circuitry. Suited for use in wired and wireless communications, imaging systems and test and measurement equipment, the LT1993 offers excellent noise and distortion performance. The low harmonic distortion of -70 dBc, combined with the 12.3 dB noise figure at 70 MHz, ensures system accuracy and high signal integrity.

Article Tools

• 

Unlike existing differential amplifiers, the LT1993 works everywhere with minimal support circuitry. The internal gain eliminates a handful of external gain setting resistors that are commonly required with other differential amplifiers. The built-in, user-adjustable low-pass filter simplifies pre-ADC filtering often desired to provide either anti-aliasing or improve signal to noise ratio. The adjustable output common mode voltage allows direct interfacing with ADCs without the need for AC-coupling capacitors or transformers. The LT1993 can be DC-coupled in applications that have frequency ranges including DC. The combination of these features eliminates external support circuitry resulting in an integrated single-chip solution that is easier to use and simpler to lay out with minimal debug and tweak time.

The LT1993-2 features fixed gain of 6 dB with 800 MHz -3 dB bandwidth. The LT1993-4 has a 12 dB fixed gain with bandwidth reaching 900 MHz. The LT1993-10 offers a high gain of 20 dB with 700 MHz bandwidth. All gain options are available for operation over the commercial and industrial temperature ranges. Offered in the low profile 3 mm x 3 mm QFN package, pricing starts at $2.95 each in 1000-piece quantities.