Features

• Sample Rate: 100ksps
• 8-Channel Multiplexer with ±25V Protection
• Single 5V Supply
• Software-Programmable Input Ranges:
  0V to 5V, 0V to 10V, ±5V or ±10V
  Single Ended or Differential
• ±3LSB INL for the LTC1859, ±1.5LSB INL for the LTC1858, ±1LSB INL for the LTC1857
• Power Dissipation: 40mW (Typ)
• SPI/MICROWIRETM Compatible Serial I/O
• Power Shutdown: Nap and Sleep
• Signal-to-Noise Ratio: 87dB (Typ) for the LTC1859
• Operates with Internal or External Reference
• Internal Synchronized Clock
• 28-Pin SSOP Package

Typical Application

Description

The LTC1857/LTC1858/LTC1859 are 8-channel, low power, 12-/14-/16-bit, 100ksps, analog-to-digital converters (ADCs). These SoftSpan ADCs can be software programmed for 0V to 5V, 0V to 10V, ±5V or ±10V input spans and operate from a single 5V supply. The 8-channel multiplexer can be programmed for single-ended inputs or pairs of differential inputs or combinations of both. In addition, all channels are fault protected to ±25V. A fault condition on any channel will not affect the conversion result of the selected channel.

An onboard high performance sample-and-hold and precision reference minimize external components. The low 40mW power dissipation is made even more attractive with two user selectable power shutdown modes. DC specifications include ±3LSB INL for the LTC1859, ±1.5LSB INL for the LTC1858 and ±1LSB for the LTC1857.

The internal clock is trimmed for 5µs maximum conversion time and the sampling rate is guaranteed at 100ksps. A separate convert start input and data ready signal (BUSY) ease connections to FIFOs, DSPs and microprocessors.