True bipolar SAR ADC simplifies input signal conditioning for 10V applications



Linear Technology introduced the LTC2338-18, an 18-bit 1Msps no latency analog-to-digital converter (ADC) with a wide 10.24V fully differential, true bipolar input range for high voltage, industrial applications. The device operates from a single 5V supply, achieves 100dB SNR and -110dB THD and features an internal 2.048V (20ppm/°C max) reference and reference buffer. 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. Linear Technology