AD7703 20-Bit Sigma-Delta ADC

The AD7703 is a 20-bit ADC which uses a sigma delta conversion technique. The analog input is continuously sampled by an analog modulator whose mean output duty cycle is proportional to the input signal. The modulator output is processed by an on-chip digital filter with a six-pole Gaussian response, which updates the output data register with 20-bit binary words at word rates up to 4kHz. The sampling rate, filter corner frequency and output word rate are set by a master clock input that may be supplied externally, or by an on-chip gate oscillator.

The inherent linearity of the ADC is excellent, and endpoint accuracy is ensured by self-calibration of zero and full scale which may be initiated at any time. The self-calibration scheme can also be extended to null system offset and gain errors in the input channel.

The output data is accessed through a serial port, which has two synchronous modes suitable for interfacing to shift registers or the serial ports of industry standard microcontrollers.

CMOS construction ensures low power dissipation, and a power down mode reduces the idle power consumption to only 10µW.

Features and Benefits
  • Monolithic 16-Bit ADC
  • 0.0015% Linearity Error
  • On-Chip Self-Calibration Circuitry
  • Programmable Low-Pass Filter
    0.1 Hz to 10 Hz Corner Frequency
  • 0 V to +2.5 V or ±2.5 V Analog Input Range
  • 4 kSPS Output Data Rate
  • Flexible Serial Interface
  • Ultralow Power
Analog to Digital Converters
Data Sheets
Documentnote
AD7703: LC2MOS 20-Bit Sigma-Delta ADC Data Sheet (Rev. E)PDF 448 kB
Application Notes
Documentnote
AN-607: Selecting a Low Bandwidth (<15 kSPS) Sigma-Delta ADC (Rev. E)PDF 222 kB
AN-349: Keys to Longer Life for CMOSPDF 89 kB
AN-375: ADM2xxL Family for RS-232 CommunicationsPDF 351 kB
AN-368: Evaluation Board for the AD7701/AD7703 Sigma-Delta ADCsPDF 507 kB
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
AD7703ANZ Production20 ld PDIPOTH 18-40 to 85C26.5822.23Y
AD7703AR Production20 ld SOIC - WideOTH 37-40 to 85C00N
AD7703ARZ Production20 ld SOIC - WideOTH 37-40 to 85C23.4419.7Y
AD7703BNZ Production20 ld PDIPOTH 18-40 to 85C31.5926.48Y
AD7703BRZ Production20 ld SOIC - WideOTH 37-40 to 85C27.8723.37Y
AD7703BRZ-REEL Production20 ld SOIC - WideREEL 1000-40 to 85C023.37Y
AD7703CNZ Production20 ld PDIPOTH 18-40 to 85C40.734.12Y
AD7703CR Production20 ld SOIC - WideOTH 37-40 to 85C00N
AD7703CRZ Production20 ld SOIC - WideOTH 37-40 to 85C32.5127.64Y
Reference Materials
AD7703: LC2MOS 20-Bit Sigma-Delta ADC Data Sheet (Rev. E) ad7703
AN-607: 选择低带宽(<15kSPS)Σ-Δ型ADC (Rev. E) ad7701
AN-349: 延长CMOS寿命的关键因素 adg3233
AN-607: Selecting a Low Bandwidth (<15 kSPS) Sigma-Delta ADC (Rev. E) ad7701
AN-349: Keys to Longer Life for CMOS ad7703
AN-375: ADM2xxL Family for RS-232 Communications ad7701
AN-368: Evaluation Board for the AD7701/AD7703 Sigma-Delta ADCs ad7701
MS-2210:高速ADC的电源设计 ad9861