link to page 4 link to page 4 link to page 4 link to page 4 link to page 5 link to page 4 link to page 4 link to page 4 18-Bit, 1.25 MSPS PulSAR® ADCAD7643FEATURESFUNCTIONAL BLOCK DIAGRAMThroughput: 1.25 MSPSTEMP REFBUFIN REF REFGNDDVDD DGNDINL: ±1.5 LSB typical, ±3 LSB maximum (±11 ppm of full scale)AGND18-bit resolution with no missing codesAD7643OVDDAVDDDynamic range: 95 dBtypicalOGNDREFSINAD: 93.5dB typical @ 20 kHz (VREF = 2.5 V)REF AMPSERIALTHD: −113 dB typical @ 20 kHz (VPORTREF = 2.5 V)IN+18SWITCHEDD[17:0]2.048 V internal reference: typical drift 8ppm/°C; TEMP outputIN–CAP DACMODE0PARALLELDifferential input range: ±VREF (VREF up to 2.5 V)INTERFACEMODE1No pipeline delay (SAR architecture)PDREFCLOCKBUSYParallel (18-, 16-, or 8-bit bus) and serial 5 V/3.3 V/2.5 V interfacePDBUFRDCONTROL LOGIC ANDSPI®/QSPI™/MICROWIRE™/DSP compatiblePDCALIBRATION CIRCUITRYCSSingle 2.5 V supply operationRESETD0/OB/2CPower dissipation -001 65 mW typical @ 1.25 MSPS with internal REFCNVST 024 06 2 μW in power-down mode Figure 1. Pb-free, 48-lead LQFP and 48-lead LFCSP_VQTable 1. PulSAR 48-Lead SelectionPin compatible with the AD7641and other PulSAR ADC’s100 to500 to650 toType/kSPS2505701000 >1000APPLICATIONS Pseudo AD7651, AD7650, AD7653, Medical instruments Differential AD7660, AD7652, AD7667 AD7661 AD7664, High speed data acquisition/high dynamic data acquisition AD7666 Digital signal processing True Bipolar AD7610, AD7665 AD7612, Spectrum analysis AD7663 AD7671 Instrumentation True AD7675 AD7676 AD7677 AD7621, Communications Differential AD7622, ATE AD7623