The AD7768 achieves 108 dB dynamic range at a maximum input bandwidth of 110.8 kHz with typical performance ±2 ppm integral nonlinearity (INL), ±50 μV offset error, and ±30 ppm gain error.
The AD7768 user has a trade-off between input bandwidth, output data rate, and power consumption. Choose one of three power modes to optimize noise targets and power consumption. The flexibility of the AD7768 makes it a reusable platform for low power dc and high performance ac measurement modules.
The AD7768 offers rich digital filtering features such as wideband, ± 0.005 dB low pass band ripple, antialiasing low-pass filter with integrated sharp roll-off performance, and 105 dB attenuation at the Nyquist frequency.
Wideband linear phase filters can be used for frequency domain measurements. The filter has a flat passband (±0.005 dB ripple) in the following ranges:D C to 102.4 kHz (256 kSPS), DC to 51.2 kHz (128 kSPS), or DC to 12.8 kHz (32 kSPS). The AD7768 also provides a sinc response (via a sinc5 filter), a low latency path with low bandwidth, and low noise measurements. Wideband and sinc5 filters can be selected and operated for each channel.
Within these filter options, the user can increase dynamic range by choosing from decimation rates × 32, ×64, ×128, ×256, ×512, and ×1024. Changing the decimation filtering capability optimizes the noise performance of the desired input bandwidth.
Embedded analog features for each ADC channel simplify design, such as a precharge buffer on the analog input to reduce analog input current, and a precharged reference buffer per channel to reduce input current and glitches at the reference input.
The device operates from 5 V AVDD1A and AVDD1B supplies, 2.25 V to 5.0 V AVDD2A and AVDD2B supplies, and 2.5 V to 3.3 V or 1.8 V IOVDD supplies (see the 1.8 V IOVDD Power Supply section for specific supply requirements for 1.8 V IOVDD).
For clarity in this document, AVDD1A and AVDD1B power supplies are referred to as AVDD1 and AVDD2A, and AVDD2B power supplies are referred to as AVDD2. For negative supplies, AVSS refers to AVSS1A, AVSS1B, AVSS2A, AVSS2B, and all other AVSS pins.
The device is specified for operation over the −40°C to +105°C temperature range and is available in a 12 mm × 12 mm, 64-lead LQFP package.
Throughout the data sheet, multifunction pins (e.g., XTAL2/MCLK) are represented by the entire pin name or by a single function of the pin (e.g., MCLK means that it is relevant only to this function).
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- Data acquisition system: USB/PXI/Ethernet
- Instrumentation and industrial control loops
- Audio test and measurement
- Vibration and asset condition monitoring
- 3-phase power quality analysis
- sonar
- High-precision medical EEG/EMG/ECG