Dual Differential Amplifier/ADC Driver Delivers 10GHz Gain Bandwidth with 1.1nV/√Hz Noise

Analog Devices LTC6419

Analog Devices, Inc., which recently acquired Linear Technology Corporation, announces the LTC6419, a dual 10 GHz gain bandwidth product differential amplifier with very low input voltage noise density of 1.1 nV/√Hz, delivering outstanding SNR performance for wideband signal amplification. Additionally, the LTC6419 offers low distortion, providing 85 dB spurious-free dynamic range (SFDR) at 100 MHz while driving 2 VP-P signals. Four external resistors set the differential gain of each amplifier, configurable from unity gain with frequency response beyond 1 GHz, to gain of 100 with bandwidth of 100 MHz, and up to a maximum gain of 400 with bandwidth of 30 MHz. At these high frequencies, the LTC6419 offers significantly better channel-to-channel isolation of 95 dB at 100 MHz than other similar class dual amplifiers. Also its wide DC common mode voltage ranges, 0 V to 3.5 V at the input, and 0.5 V to 3.5 V 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.

Analog Devices - LTC6419

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.

DC-Coupled Interface from a Ground-Referenced Single-Ended Input to an LTC2175-14 ADC
DC-Coupled Interface from a Ground-Referenced Single-Ended Input to an LTC2175-14 ADC.

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

The LTC6419 is offered in a small 4 mm × 3 mm × 0.75 mm, 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. The LTC6419 I grade is priced starting at $8.50 and the H grade starting at $9.90 each in 1,000-pieces quantities. Both are available immediately in production quantities.

1/2 LTC6419 Driving 1/4 LTC2175-14 ADC, fIN = 45 MHz, -1 dBFS, fS = 125 MHz, 32768-Point FFT
1/2 LTC6419 Driving 1/4 LTC2175-14 ADC, fIN = 45 MHz,
–1 dBFS, fS = 125 MHz, 32768-Point FFT
.

Summary of Features: LTC6419

  • Configurable Gain and Bandwidth:
    • Unity Gain at 1.4 GHz
    • Gain = 100 at 100 MHz
    • Gain = 400 at 30 MHz
  • 1.1 nV/ÖHz Input Voltage Noise Density with 40 kHz Noise Corner Frequency
  • Wide DC Common Mode Voltage Range:
    • Input: 0 V to 3.5 V
    • Output: 0.5 V to 3.5 V
  • Channel Separation 95 dB at 100 MHz
  • Industrial and High Temperature Grades Offered:
    • I Grade: –40 °C to 85 °C
    • H Grade: –40 °C to 125 °C