AD7725BSZ 16-bit sigma-delta type ADC with built-in programmable postprocessor
The AD7725 is a complete 16-bit, sigma-delta analog-to-digital converter (ADC) with built-in on-chip user-programmable signal conditioning. The modulator output is handled by three cascading finite impulse response (FIR) filters and a user-programmable post-processor on the rear. The user has complete control over the filter response, filter coefficient, and extraction rate.
The AD7725 is rated for up to 300 kHz input bandwidth and a maximum output word rate of 600 kHz. The input sampling rate is set by a crystal oscillator or an external clock and is rated at 9.6MHz with a maximum of 14.4MHz. The CLKIN frequency directly determines the maximum input bandwidth of the device, and the relationship between the two is BW (max) = CLKIN/32. Conversion data is available via serial or parallel interfaces.
To program the postprocessor, on-chip default filters or user-defined filters can be onboarded into the device in the form of a configuration file. User-defined filters can be loaded from a DSP with a serial interface or from an external EPROM, or from a DSP with a parallel interface.
A digital filter design package called the Filter Wizard can be used to generate user-defined filter profiles. With this design package, users can design different types of filters and generate corresponding profiles for onboarding into the device.
Features and Benefits:
Programmable filtering:
- Any characteristics of up to 108th order FIR and/or IIR
Polynomial signal conditioning, up to the eighth order
Flexible Programming Modes:
- Import from DSP or external EPROM
- Parallel/serial interface
Internal default filter for evaluation
Programmable extraction and output word rates
Master clock frequency: 14.4 MHz max
Input Range: 0 V to +4 V (single-ended) or ±2 V (differential)
AVDD, DVD Power Supply: 5 V ± 5%
2.5 V on-chip reference
44-Pin MQFP Package //www.chip100.com/