Microwave Journal

Dual Differential Amplifier/ADC Driver Delivers 10GHz Gain Bandwidth

March 22, 2017

Analog Devices, Inc., which recently acquired Linear Technology Corporation, announced the LTC6419, a dual 10GHz gain bandwidth product differential amplifier with very low input voltage noise density of 1.1nV/√Hz, delivering outstanding SNR performance for wideband signal amplification. Additionally, the LTC6419 offers low distortion, providing 85dB spurious-free dynamic range (SFDR) at 100MHz while driving 2VP-P signals. Four external resistors set the differential gain of each amplifier, configurable from unity gain with frequency response beyond 1GHz, to gain of 100 with bandwidth of 100MHz, and up to a maximum gain of 400 with bandwidth of 30MHz. According to Analog Devices, at these high frequencies, the LTC6419 offers significantly better channel-to-channel isolation of 95dB at 100MHz than other similar class dual amplifiers. Also its wide DC common mode voltage ranges, 0V to 3.5V at the input, and 0.5V to 3.5V at the output, make the part particularly useful in DC coupled applications interfacing between two dissimilar DC levels, such as from the outputs of an I/Q demodulator to the inputs of analog-to-digital (A/D) converters.

The LTC6419 dual differential amplifier, with its DC coupling, low noise and high bandwidth capabilities, is well suited for many applications such as direct conversion receivers, driving high sample rate ADCs, high speed data acquisition systems, test instrumentation, high resolution radar systems, advanced image sensors and LIDAR systems.

The LTC6419 has a supply voltage range from 2.7V to 5.25V. Each amplifier also has a shutdown pin, so each amplifier can be enabled independently, drawing a nominal supply current of 52mA. When disabled, the supply current reduces to 100μA per amplifier.

The LTC6419 is offered in a small 4mm x 3mm x 0.75mm, 20-lead LQFN plastic package. Two grades are offered: an I grade rated from –40°C to 85°C and an H grade from –40°C to 125°C.