Linear Technology has introduced a 33 MHz, low noise, rail-to-rail input and output ADC driver that settles to 16-bits in just 350 ns.
The LT6350 is suitable for driving the latest highest performance SAR ADCs such as the LTC2393-16. The LT6350 incorporates two op amps and matched resistors to create a differential output from a single-ended high impedance input. As a result, a differential gain of 2 is achieved with no external feedback resistors, and higher gain can be obtained by using feedback resistors. Each of the two internal op amps achieve a low 1.9 nV/√Hz input-referred noise density, resulting in a total output-referred noise of just 8.2 nV/√Hz. The LT6350 enables high performance ADCs to achieve better than 110 dB SNR over a 1 MHz bandwidth.
The input op amp is trimmed for constant low differential input-referred voltage offset over the input range to prevent VOS steps from degrading distortion. At 100 kHz, the LT6350 can typically achieve -102/-97dBc HD2/HD3.
The LT6350 provides rail-to-rail input and output range. With a single 5 V supply, the outputs can swing 0.055 V to 4.945 V, and by using a negative supply, the outputs can each swing from 0 V to 4.945 V. The LT6350 operates on 2.7 V to 12 V total supply. The LT6350 consumes 4.8 mA supply current and has a shutdown mode that allows the system to reduce power consumption during periods of inactivity.
Summary of Features: LT6350
- Rail-to-Rail Input & Outputs
- Fast Settling Time: 240 ns, 0.01 percent, 8 VP-P Output Step
- 1.9 nV/√Hz Input-Referred Op Amp Noise
- High Impedance Input
- No External Gain-Resistors Required
- 2.7 V to 12 V Supply Operation, 4.8 mA Supply Current
- Low Power Shutdown
- Low Distortion (HD2/HD3):
— -102 dBc/-97 dBc at 100 kHz, VOUTDIFF = 4 VP-P
- High DC Linearity:
— < ± 1LSB, 16-Bit, 8 VP-P
- 3 mm x 3 mm 8-Pin DFN & 8-Lead MSOP Packages
Availability and Pricing
Fully specified commercial (0 to 70 degrees C), industrial (-40 to 85 degrees C) and extended (-40 to 125 degrees C) temperature range versions of the LT6350 are available in 8-lead MSOP and 3 mm x 3 mm DFN packages. Prices start at $2.59 each in quantities of 1,000 pieces.