Many systems using a precision analog-to-digital converter to digitize signals need some signal conditioning circuitry between the signal source and the ADC. In addition to its other functions, that circuitry must accurately drive the input of the ADC. The combined demands of performance and high speed to handle the ADC input currents can present a substantial additional design challenge.
To simplify and improve these systems, the LTC2358 octal ADC adds FET-input analog buffers to the performance and flexibility of the LTC2348. These buffers allow the signal conditioning to be designed around the needs of the signal, rather than the needs of the ADC. The purely capacitive picoamp inputs can be directly connected to a variety of delicate, low-current sensors and ease the design of analog antialiasing filters and other functions.
Other features include differential inputs with 30VP-P common mode range, independent SoftSpan control of each channel’s analog input range on a conversion-by-conversion basis, and pin-selectable SPI CMOS and LVDS serial I/O interface options to ease integration with your existing digital system.