Linear Technology Corporation introduces the LTC2335-18, an 18-bit, 8-channel 1 Msps 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 ±10.24 V, 0 V to 10.24 V, ±5.12 V or 0 V to 5.12 V true bipolar input signals. The on-chip sequencer allows the LTC2335-18 to be programmed to cycle through a sequence of channels and ranges without further user intervention. The differential analog inputs operate over a wide –16.5 V to 34V input common mode range, allowing the ADC to directly digitize a variety of signals to simplify signal-chain design. The input signal flexibility, combined with unrivaled 96.7 dB SNR and 1 Msps 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 20 ppm/°C maximum temperature coefficient and an integrated reference buffer capable of accurate one-shot measurements, providing space savings in densely packed circuit boards. Optionally, an external 5 V reference may be used to expand the analog input range to ±12.5 V. The device dissipates 180 mW when converting at 1 Msps, and features nap and power-down modes to reduce power dissipation at slower throughputs.
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| Integral Nonlinearity vs Output Code and Channel. |
The LTC2335-18 features pin-selectable SPI CMOS and LVDS serial interfaces. The wide digital output supply range allows the device to communicate with any CMOS logic between 1.8 V and 5 V. The serial LVDS mode offers low noise, high speed communications over greater distances using differential signaling. Together, these I/O interface options enable the LTC2335-18 to communicate equally well with legacy microcontrollers and modern FPGAs.
The LTC2335-18 joins a high performance family of multichannel 18-/16-bit SAR ADCs with true bipolar ±10.24 V simultaneous sampling inputs (LTC2348). All specifications are guaranteed over the extended –40 °C to 125 °C temperature range. The LTC2335-18 is available now in a 48-lead, 7 mm × 7 mm LQFP package and is priced starting at $18.95 each in 1,000- piece quantities.
Summary of Features: LTC2335-18
- 1 Msps Throughput
- Eight Multiplexed Inputs Channels
- ±3 LSB INL (Maximum, ±10.24 V Range)
- Guaranteed 18-Bit, No Missing Codes
- Differential, Wide Common Mode Range Inputs
- Per-Channel SoftSpan Input Ranges:
- ±10.24 V, 0 V to 10.24 V, ±5.12 V, 0 V to 5.12 V
- ±12.5 V, 0 V to 12.5 V, ±6.25 V, 0 V to 6.25 V
- 96.7 dB Single-Conversion SNR (Typical)
- Integrated Reference & Buffer
- 2.5 V to 5 V External Reference Input Range
- Programmable Sequencer with No-Latency Control
- SPI CMOS (1.8 V to 5 V) & LVDS Serial I/O
- 180 mW Power Dissipation (Typical)
- 48-Lead 7 mm × 7 mm LQFP Package
