AD7722
PRODUCTION
16-Bit, 195 kSPS CMOS, Sigma-Delta ADC
- Part Models
- 1
- 1ku List Price
- Starting From $25.61
Overview
- 16-Bit Σ-Δ ADC
64 x Oversampling Ratio
Up to 220 kSPS Output Word Rate
Low-Pass, Linear Phase Digital Filter
- Inherently Monotonic
- On-Chip 2.5 V Voltage Reference
- Single-Supply 5 V
- High Speed Parallel or Serial Interface
The AD7722 is a complete low power, 16-bit, sigma-delta ADC. The part operates from a +5 V supply and accepts a differential input voltage range of 0 V to +2.5 V or ±1.25 V centered around a common-mode bias. The AD7722 provides 16-bit performance for input bandwidths up to 90.625 kHz. The part provides data at an output word rate of 195.3 kHz.
The analog input is continuously sampled by an analog modulator eliminating the need for external sample-and-hold circuitry. The modulator output is processed by two Finite Impulse Response (FIR) digital filters in series. The on-chip filtering reduces the external antialias requirements to first order, in most cases. The group delay for the filter is 215.5 µs, while the settling time for a step input is 431 µs. The sample rate, filter corner frequency, and output word rate are set by an external clock that is nominally 12.5 MHz.
Use of a single bit DAC in the modulator guarantees excellent linearity and dc accuracy. Endpoint accuracy is ensured by on-chip calibration. This calibration procedure minimizes the zero-scale and full-scale errors.
Conversion data is provided at the output register through a flexible serial port or a parallel port. This offers 3-wire, high speed interfacing to digital signal processors. The serial interface operates in an internal clocking (master) mode, whereby an internal serial data clock and framing pulse are device outputs. Additionally, two AD7722s can be configured with the serial data outputs connected together. Each converter alternately transmits its conversion data on a shared serial data line.
The part provides an accurate on-chip 2.5 V reference. A reference input/output function is provided to allow either the internal reference or an external system reference to be used as the reference source for the part.
The AD7722 is available in a 44-pin PQFP package and is specified over the industrial temperature range from –40°C to +85°C.
Documentation
Data Sheet 1
Application Note 6
Technical Articles 4
Evaluation Design File 1
Analog Dialogue 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| AD7722ASZ | 44-Lead MQFP (13.9mm x 10mm) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Jan 5, 2009 - 07_0077 Certification of STATSChipPAC Shanghai, China and AMKOR Philippines as additional sources for Assembly & Test of QFP Packages |
||
| AD7722ASZ | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Request a Driver/SoftwareTools & Simulations
Sigma-Delta ADC Tutorial
An interactive illustration showing the behavior of an idealized sigma-delta A/D converter.
Open ToolEvaluation Kits
AD7722 Evaluation Board