18-Bit, 250 kSPS PulSARDifferential ADC in MSOPEnhanced ProductAD7691-EPFEATURESAPPLICATION DIAGRAM18-bit resolution with no missing codes+0.5V TO VDD+2.5V TO +5VThroughput: 250 kSPS INL±0.75 LSB typicalREF VDD VIO+1.8V TO VDD±1.5 LSB minimum/maximum at −40°C to +85°CIN+SDISCK3- OR 4-WIRE−2.7 LSB/+2 LSB minimum/maximum at −55°C to +105°C±10V, ±5V, ...INTERFACEIN–SDO(SPI, DAISY CHAIN, CS)Dynamic range: 102 dB typicalGNDCNVADA4941Oversampled dynamic range: 125 dB at 1 kSPS 001 6- Noise-free code resolution: 20 bits at 1 kSPSAD7691-EP 215 1 Effective resolution: 22.7 bits at 1 kSPS Figure 1. SINAD: 101 dB typical at fIN = 1 kHz, VREF = 5 VGENERAL DESCRIPTIONTHD: −125 dB typical at fIN = 1 kHz, VREF = 5 V The AD7691-EP is an 18-bit, charge redistribution, successive True differential analog input range: ±VREF approximation, analog-to-digital converter (ADC) that operates 0 V to VREF with VREF up to VDD on both inputs from a single power supply, VDD, between 2.3 V and 5 V. It No pipeline delay contains a low power, high speed, 18-bit sampling ADC with Single-supply 2.3 V to 5 V operation with 1.8 V/2.5 V/3 V/5 V no missing codes, an internal conversion clock, and a versatile logic interface serial interface port. On the CNV rising edge, it samples the Serial interface SPI-/QSPI™-/MICROWIRE™-/DSP-compatible voltage difference between the IN+ and IN− pins. The voltages Ability to daisy-chain multiple ADCs on these pins swing in opposite phases between 0 V and REF. Optional busy indicator feature Power dissipation The reference voltage, REF, is applied externally and can be set 1.35 mW at VDD = 2.5 V, 100 kSPS throughput up to the supply voltage. 4.24 mW at VDD = 5 V, 100 kSPS throughput The power of the AD7691-EP scales linearly with throughput. 1.4 μW at VDD = 2.5 V, 100 SPS throughput The SPI-compatible serial interface also features the ability, using Standby current: 1 nA 10-lead MSOP the SDI input, to daisy-chain several ADCs on a single 3-wire Pin-for-pin compatible with the18-bit AD7690 and16-bit bus and provides an optional busy indicator. It is compatible with AD7693,AD7688, andAD7687 1.8 V, 2.5 V, 3 V, or 5 V logic, using the separate VIO supply. The AD7691-EP is housed in a 10-lead MSOP with operation ENHANCED PRODUCT FEATURES specified from −55°C to +105°C. Additional application and Supports defense and aerospace applications (AQEC standard) technical information can be found in the AD7691 data sheet. Military temperature range: −55°C to +105°C1.5Controlled manufacturing baselinePOSITIVE INL = 0.43LSB NEGATIVE INL = –0.62LSBOne assembly/test site1.0One fabrication site Enhanced product change notification0.5Qualification data available on request) B SAPPLICATIONSL (0LBattery-powered equipmentINData acquisitions–0.5Seismic data acquisition systems Instrumentation–1.0Medical instruments–1.5065536131072196608262144 -025