IN鈥?/div>
V
IN+
DIFF
MULTIBIT
危-螖
MODULATOR
AV
DD1
AV
DD2
AV
DD3
V
REF+
BUF
REFGND
RECONSTRUCTION
AV
DD4
DECAPA
DECAPB
AD7763
MCLK
MCLKGND
SYNC
RESET
SH2:0
ADR2:0
CDIV
CONTROL LOGIC
I/O
OFFSET AND GAIN
REGISTERS
PROGRAMMABLE
DECIMATION
R
BIAS
AGND
V
DRIVE
DV
DD
FIR FILTER
ENGINE
DGND
SDL
DRDY
SCO
FSO
Figure 1.
APPLICATIONS
Data acquisition systems
Vibration analysis
Instrumentation
GENERAL DESCRIPTION
The AD7763 high performance, 24-bit, 危-螖 analog-to-digital
converter (ADC) combines wide input bandwidth and high
speed with the benefits of 危-螖 conversion, as well as performance
of 107 dB SNR at 625 kSPS, making it ideal for high speed data
acquisition. A wide dynamic range, combined with significantly
reduced antialiasing requirements, simplifies the design process.
An integrated buffer to drive the reference, a differential ampli-
fier for signal buffering and level shifting, an overrange flag,
internal gain and offset registers, and a low-pass, digital FIR
filter make the AD7763 a compact, highly integrated data
acquisition device requiring minimal peripheral component
selection. In addition, the device offers programmable
decimation rates and a digital FIR filter, which can be user-
programmed to ensure that its characteristics are tailored for the
user鈥檚 application. The AD7763 is ideal for applications demanding
high SNR without necessitating the design of complex, front-
end signal processing.
The differential input is sampled at up to 40 MSPS by an analog
modulator. The modulator output is processed by a series
of low-pass filters, the final filter having default or user-
programmable coefficients. The sample rate, filter corner
frequencies, and output word rate are set by a combination of
the external clock frequency and the configuration registers of
the AD7763.
The reference voltage supplied to the AD7763 determines the
analog input range. With a 4 V reference, the analog input range
is 卤3.2 V differential-biased around a common mode of 2 V.
This common-mode biasing can be achieved using the on-chip
differential amplifiers, further reducing the external signal
conditioning requirements.
The AD7763 is available in an exposed paddle, 64-lead TQFP_EP
and is specified over the industrial temperature range from
鈭?0掳C to +85掳C.
Table 1. Related Devices
Part No.
AD7760
AD7762
Description
24-bit, 2.5 MSPS, 100 dB 危-螖, parallel interface
24-bit, 625 kSPS, 109 dB 危-螖, parallel interface
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
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