Linear Technology has introduced a new 18-bit, 8-channel 1Msps multiplexed input successive approximation register (SAR) ADC with independently configurable input ranges. Each SoftSpan input can be software configured on a conversion-by-conversion basis to accept true bipolar input signals of ± 10.24V, 0V to 10.24V, ± 5.12V, or 0V to 5.12V.
The on-chip sequencer allows the LTC2335-18 to be programmed to cycle through a range of channels and ranges without further user intervention. The differential analog input operates over a wide input common-mode range of -16.5V to 34V, allowing the ADC to directly digitize various signals to simplify signal chain design. The flexibility of the input signal combined with an unparalleled 96.7dB SNR and 1Msps throughput makes the LTC2335-18 ideal for high-performance industrial process control, test and measurement, power line monitoring, and instrumentation applications.
The LTC2335-18 features a precision internal reference with a maximum temperature coefficient of 20ppm / C, and an integrated reference buffer for accurate one-time measurements, saving space on densely packed circuit boards. Optionally, an external 5V reference voltage can be used to extend the analog input range to ± 12.5V. When switching at a rate of 1Msps, the device dissipates 180mW of power and has a snooze and power-down mode to reduce power consumption at slower throughput rates.
The LTC2335-18 has pin-selectable SPI CMOS and LVDS serial interfaces. The wide digital output power range allows the device to communicate with any CMOS logic between 1.8V and 5V. Serial LVDS mode uses differential signal transmission to achieve low noise and high-speed communication over longer distances. These I / O interface options together enable the LTC2335-18 to communicate well with traditional microcontrollers and modern FPGAs.
The LTC2335-18 joins the high-performance multi-channel 18- / 16-bit SAR ADC family with true bipolar ± 10.24V synchronous sampling input (LTC2348). All specifications are guaranteed over the -40C to 125C extended temperature range. The LTC2335-18 is available now in a 48-lead 7mm x 7mm LQFP package. The company says it also offers samples and demo boards.
