Analog Devices Inc. AD1555APZ

Description
The AD1555 is a complete sigma-delta modulator combined with a programmable gain amplifier for low-frequency, high dynamic range measurement applications. It outputs a ones-density bitstream proportional to the analog input. When used with the AD1556 digital filter/decimator, it forms a high-performance ADC.
The continuous-time analog modulator input architecture eliminates the need for an external antialias filter. The programmable gain front end simplifies system design, extends the dynamic range, and reduces the system board area. Low operating power and standby modes make the AD1555 ideal for remote battery-powered data acquisition systems.

Features
Large dynamic range: 116 dB min, 120 dB typical @ 1 ms; 117 dB typical @ 0.5 ms
Low input noise: 80 nV rms @ 4 ms with gain of 34,128
Low distortion: -111 dB max, -120 dB typical
Low intermodulation: 122 dB
Sampling rate at 256 KSPS
Very high jitter tolerance
No external antialias filter required
Programmable gain front end:
Input range: ±2.25 V
Robust inputs
Gain settings: 1, 2.5, 8.5, 34, 128
Common-mode rejection (DC to 1 kHz): 93 dB min, 101 dB typical @ gain of 1
77 mW typical low power dissipation
Standby modes
Reference design and evaluation board with software available

Applications
Seismic data acquisition systems
Chromatography
Automatic test equipment