Milpitas, Calif. Linear Technology released the LTC6400-20 and LTC6401-20, ADC drivers which operate from a single 3 V supply. These fully differential amplifiers include gain-setting resistors, which aid in the driving of high-speed ADCs. The LTC6400-20 provides a fixed gain of 20 dB with -93 dBc third-order intermodulation distortion (IMD3) performance and noise figure of 6.5 dB for a 140 MHz input frequency. At 240 MHz, IMD3 is better than -70 dBc.
The LTC6400-20 provides a differential output-voltage swing of 4.4 VP-P. In addition to minimizing power consumption, this eliminates the need for a separate 5 V supply in applications using the latest 3 V and 3.3 V ADCs. To further simplify interfacing to high speed ADCs, a VOCM pin sets the output common-mode voltage of the LTC6400-20 to match the input range of the ADC. An optional on-chip filter helps to handle charge injection common to the capacitive inputs characteristic of pipelined ADCs. Inputs may be AC- or DC-coupled. While fully differential, the LTC6400-20 can be used to convert single-ended inputs to differential outputs.
The LTC6401-20 is a lower-power part used for lower-input frequencies. Consuming 50 mA, the LTC6401-20 maintains the same low-noise performance and -90 dBc distortion performance for input frequencies up to 70 MHz.
Pricing: Begins at $2.95 each in 1,000-piece quantities
Data Sheet: LTC6400-20/401-20 ADCs
Linear Technology, 408-432-1900, www.linear.com