Linear introduces 18-bit 1Msps no latency ADC

An input divider network scales and level shifts the input signal, eliminating complicated circuitry required to directly interface true bipolar signals.

The LTC2338-18 leads a pin- and software-compatible family of 18-bit serial SPI SAR ADCs with speeds ranging from 250ksps to 1Msps. A pin-compatible 16-bit and 18-bit family with pseudo differential true bipolar inputs (LTC2328-18) will also be available. The proprietary internal reference buffer maintains less than 1LSB error during sudden burst of conversions, enabling true one-shot operation after lengthy idle periods. These ADCs operate from a single 5V supply and consume just 50mW at 1Msps. Power further reduces linearly at slower sample rates. A shutdown mode dissipates only 300µW when idle.

The DC1908A demonstration board enables easy evaluation of the LTC2338 family in conjunction with the DC590B (QuikEval) or DC718C (PScope) data collection boards. The fully differential LTC2338-18 and pseudo differential LTC2328-18 families are available in small MSOP-16 packages in commercial, industrial and automotive temperature grades. Pricing begins at $29.10 in 1,000 piece quantities.

Key features:

• 1Msps Throughput Rate,
• ±4LSB INL Max,
• Fully Differential Inputs,
• True Bipolar Input Ranges ±6.25V, ±10.24V, ±12.5V,
• 100dB SNR (Typ) at f_IN = 2kHz,
• –110dB THD (Typ) at f_IN = 2kHz,
• Guaranteed Operation to 125°C,
• 5V Supply,
• Low Drift (20ppm/°C Max) 2.048V Internal Reference,
• Onboard Single-Shot Capable Reference Buffer,
• No Pipeline Delay, No Cycle Latency,
• 1.8V to 5V I/O Voltages,
• SPI-Compatible Serial I/O with Daisy-Chain Mode,
• Internal Conversion Clock,
• Power Dissipation 50mW (Typ),
• 16-Lead MSOP Package.