24-Bit, 8.5 mW, 109 dB,
128/64/32 kSPS ADCs
AD7767
FEATURES
Oversampled successive approximation (SAR) architecture
High performance ac and dc accuracy, low power
115.5 dB dynamic range, 32 kSPS (AD7767-2)
112.5 dB dynamic range, 64 kSPS (AD7767-1)
109.5 dB dynamic range, 128 kSPS (AD7767)
−118 dB THD
Exceptionally low power
8.5 mW, 32 kSPS (AD7767-2)
10.5 mW, 64 kSPS (AD7767-1)
15 mW, 128 kSPS (AD7767)
High dc accuracy
24 bits, no missing codes (NMC)
INL: ±3 ppm (typical), ±7.6 ppm (maximum)
Low temperature drift
Zero error drift: 15 nV/°C
Gain error drift: 0.0075% FS
On-chip low-pass FIR filter
Linear phase response
Pass-band ripple: ±0.005 dB
Stop-band attenuation: 100 dB
2.5 V supply with 1.8 V/2.5 V/3 V/3.6 V logic interface options
Flexible interfacing options
Synchronization of multiple devices
Daisy chain capability
Power-down function
Temperature range: −40°C to +105°C
GENERAL DESCRIPTION
The AD7767/AD7767-1/AD7767-2 are high performance
24-bit oversampled SAR analog-to-digital converters (ADC).
The AD7767/AD7767-1/AD7767-2 combine the benefits of a
large dynamic range and input bandwidth, consuming 15 mW,
10.5 mW, and 8.5 mW power, respectively, all contained in a
16-lead TSSOP package.
Ideal for ultralow power data acquisition (such as PCI- and
USB-based systems), the AD7767/AD7767-1/AD7767-2
provide 24-bit resolution. The combination of exceptional SNR,
wide dynamic range, and outstanding dc accuracy make the
AD7767/AD7767-1/AD7767-2 ideally suited for measuring
small signal changes over a wide dynamic range. This is
particularly suitable for applications where small changes on the
input are measured on larger ac or dc signals. In such an
application, the AD7767/AD7767-1/AD7767-2 accurately
gather both ac and dc information.
The AD7767/AD7767-1/AD7767-2 include an on-board digital
filter (complete with linear phase response) that acts to elimi-
nate out-of-band noise by filtering the oversampled input
voltage. The oversampled architecture also reduces front-end
antialias requirements. Other features of the AD7767 include a
SYNC/PD (synchronization/power-down) pin, allowing the
synchronization of multiple AD7767 devices. The addition of
an SDI pin provides the option of daisy chaining multiple
AD7767 devices.
The AD7767/AD7767-1/AD7767-2 operate from a 2.5 V supply
using a 5 V reference. The devices operate from −40°C to +105°C.
APPLICATIONS
Low power PCI/USB data acquisition systems
Low power wireless acquisition systems
Vibration analysis
Instrumentation
High precision medical acquisition
RELATED DEVICES
Table 1. 24-Bit Analog-to-Digital Converters
Part No.
SYNC/PD
FUNCTIONAL BLOCK DIAGRAM
AV
DD
AGND MCLK
V
REF+
V
IN+
SUCCESSIVE-
APPROXIMATION
ADC
V
IN–
REFGND
DIGITAL
FIR FILTER
DV
DD
V
DRIVE
DGND
1
SCLK DRDY SDO
SDI
06859-001
AD7767/
AD7767-1/
AD7767-2
SERIAL INTERFACE
AND
CONTROL LOGIC
CS
Description
2.5 MSPS, 100 dB dynamic range
, on-board differential
amp and reference buffer, parallel, variable decimation
625 kSPS, 109 dB dynamic range
, on-board differential
amp and reference buffer, parallel/serial, variable
decimation
312 kSPS, 109 dB dynamic range
, on-board differential
amp and reference buffer, variable decimation (pin)
156 kSPS, 112 dB dynamic range
, on-board differential
amp and reference buffer, variable decimation (pin)
128 kSPS, 109.5 dB
, 15 mW, 16-bit INL, serial interface
64 kSPS 112.5 dB
,10.5 mW, 16-bit INL, serial interface
32 kSPS, 115.5 dB
, 8.5 mW, 16-bit INL, serial interface
Figure 1.
Rev. 0
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rights of third parties that may result from its use. Specifications subject to change without notice. No
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Trademarks and registered trademarks are the property of their respective owners.
Dynamic range at maximum output data rate.
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