24-Bit, 312 kSPS, 109 dB Sigma-Delta ADC
with On-Chip Buffers and Serial Interface
High performance 24-bit ∑-∆ ADC
115 dB dynamic range at 78 kHz output data rate
109 dB dynamic range at 312 kHz output data rate
312 kHz maximum fully filtered output word rate
Pin-selectable oversampling rate (64×, 128×, and 256×)
Low power mode
Fully differential modulator input
On-chip differential amplifier for signal buffering
On-chip reference buffer
Full band low-pass finite impulse response (FIR) filter
Overrange alert pin
Digital gain correction registers
Synchronization of multiple devices via SYNC pin
Data acquisition systems
FUNCTIONAL BLOCK DIAGRAM
VOUTA– VOUTA+ VIN+ VIN–
INTERFACE LOGIC AND
OFFSET AND GAIN
FIR FILTER ENGINE
FSO SCO SDI SDO FSI
Table 1. Related Devices
Part No. Description
AD7760 2.5 MSPS, 100 dB, parallel output on-chip buffers
AD7762 625 kSPS, 109 dB, parallel output on-chip buffers
AD7763 625 kSPS, 109 dB, serial output, on-chip buffers
AD7765 156 kSPS, 112 dB, serial output, on-chip buffers
AD7766 128/64/32 kSPS, 8.5 mW, 109 dB SNR
AD7767 128/64/32 kSPS, 8.5 mW, 109 dB SNR
The AD7764 is a high performance, 24-bit sigma-delta (Σ-Δ)
analog-to-digital converter (ADC). It combines wide input
bandwidth, high speed, and performance of 109 dB dynamic
range at a 312 kHz output data rate. With excellent dc
specifications, the converter is ideal for high speed data
acquisition of ac signals where dc data is also required.
Using the AD7764 eases the front-end antialias filtering
requirements, simplifying the design process significantly. The
AD7764 offers pin-selectable decimation rates of 64×, 128×,
and 256×. Other features include an integrated buffer to drive
the reference, as well as a fully differential amplifier to buffer
and level shift the input to the modulator.
An overrange alert pin indicates when an input signal has
exceeded the acceptable range. The addition of internal gain
and internal overrange registers makes the AD7764 a compact,
highly integrated data acquisition device requiring minimal
The AD7764 also offers a low power mode, significantly
reducing power dissipation without reducing the output data
rate or available input bandwidth.
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.
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 external clock frequency applied to the
AD7764 determines the sample rate, filter corner frequencies,
and output word rate.
The AD7764 device boasts a full band on-board FIR filter. The
full stop-band attenuation of the filter is achieved at the Nyquist
frequency. This feature offers increased protection from signals
that lie above the Nyquist frequency being aliased back into the
input signal bandwidth.
The reference voltage supplied to the AD7764 determines the
input range. With a 4 V reference, the analog input range is
±3.2768 V differential, biased around a common mode of
2.048 V. This common-mode biasing can be achieved using
the on-chip differential amplifier, further reducing the external
signal conditioning requirements.
The AD7764 is available in a 28-lead TSSOP package and is
specified over the industrial temperature range of −40°C
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