900MHz Low Distortion, Low Noise Differential Amplifier/ADC Driver (A = 4V/V)

The LT1993-4 is a low distortion, low noise Differential Amplifier/ADC driver for use in applications from DC to 900MHz. The LT1993-4 has been designed for ease of use, with minimal support circuitry required. Exceptionally low input-referred noise and low distortion products (with either single-ended or differential inputs) make the LT1993-4 an excellent solution for driving high speed 12-bit and 14-bit ADCs. In addition to the normal unfiltered outputs (+OUT and -OUT), the LT1993-4 has a built-in 175MHz differential lowpass filter and an additional pair of filtered outputs (+OUTFILTERED, -OUTFILTERED) to reduce external filtering components when driving high speed ADCs. The output common mode voltage is easily set via the VOCM pin, eliminating either an output transformer or AC-coupling capacitors in many applications.

The LT1993-4 is designed to meet the demanding requirements of communications transceiver applications. It can be used as a differential ADC driver, a general-purpose differential gain block, or in any other application requiring differential drive. The LT1993-4 can be used in data acquisition systems required to function at frequencies down to DC.

The LT1993-4 operates on a 5V supply and consumes 100mA. It comes in a compact 16-lead 3 × 3 QFN package and operates over a -40°C to 85°C temperature range.

Applications

* Differential ADC Driver for:

* Imaging

* Communications

* Differential Driver/Receiver

* Single Ended to Differential Conversion

* Differential to Single Ended Conversion

* Level Shifting

* IF Sampling Receivers

* SAW Filter Interfacing/Buffering

* 900MHz −3dB Bandwidth

* Fixed Gain of 4V/V (12dB)

* Low Distortion:

* 40dBm OIP3, −73dBc HD3 (70MHz 2VP-P)

* 51dBm OIP3, −94dBc HD3 (10MHz 2VP-P)

* Low Noise: 14.5dB NF, en = 2.35nV/√Hz (70MHz)

* Differential Inputs and Outputs