The AD7643 is an 18-bit, 1.25 MSPS, charge redistribution SAR, fully differential, analog-to-digital converter (ADC) that operates from a single 2.5 V power supply. The part contains a high speed, 18-bit sampling ADC, an internal conversion clock, an internal reference (and buffer), error correction circuits, and both serial and parallel system interface ports. The part has no latency and can be used in asynchronous rate applications. The AD7643 is hardware factory calibrated and tested to ensure ac parameters, such as signal-to-noise ratio (SNR), in addition to the more traditional dc parameters of gain, offset, and linearity. The AD7643 is available in Pb-free only packages with operation specified from −40°C to +85°C.PRODUCT HIGHLIGHTSFast Throughput. The AD7643 is a 1.25MSPS, charge redistribution, 18-bit SAR ADC.Superior Linearity. The AD7643 has no missing 18-bit code.Internal Reference. The AD7643 has a 2.048 V internal reference with a typical drift of ±10 ppm/°C and an on-chip TEMP sensor.Single-Supply Operation. The AD7643 operates from a 2.5 V single supply.Serial or Parallel Interface. Versatile parallel (18-, 16-, or 8-bit bus) or 2-wire serial interface arrangement compatible with 2.5 V, 3.3 V, or 5 V logic.APPLICATIONSMedical instrumentsHigh speed data acquisition/high dynamic data acquisitionDigital signal processingSpectrum analysisInstrumentationCommunicationsATE