产品详情

The ADAQ7768-1 is a 24-bit precision data acquisition (DAQ) μModule system that encapsulates signal conditioning, conversion and processing blocks into one system in package (SiP) design that enables rapid development of highly compact, high performance precision DAQ systems.

The ADAQ7768-1 consists of:

• A low noise, low bias current, high bandwidth programmable gain instrumentation amplifier (PGIA) that is also capable of signal amplification and signal attenuation while maintaining high input impedance
• A fourth order, low noise, linear phase anti-aliasing filter
• A low noise, low distortion, high bandwidth ADC driver plus an optional linearity boost buffer
• A high-performance medium bandwidth 24-bit sigma delta ADC with programmable digital filter
• A low noise, low dropout linear regulator
• A reference buffers
• Critical passive components required for the signal chain

The ADAQ7768-1 supports fully differential input signal with a maximum range of ±12.6V. It has an input common mode voltage range of ±12V with excellent common mode rejection ratio (CMRR).

The input signal is fully buffered with very low input bias current of 2 pA typical. This allows easy input impedance matching and enables the ADAQ7768-1 to directly interface to sensors with high output impedance.

The seven pin-configurable gain settings offer additional system dynamic range and improved signal chain noise performance with input signals of lower amplitude.

A 4(th) order low-pass filter combined with the user programmable digital filter ensures the signal chain is fully protected against the high frequency noise and out of band tones presented at the input node from aliasing back into the band of interest. The low pass filter is carefully designed to achieve high phase linearity and maximum in-band magnitude response flatness. Constructed with Devices’s iPASSIVES technology, the resistor network used within the low-pass filter possess superior resistance matching in both absolute values and over temperature. As a result, the signal chain performance is maintained with minimum drift over temperature and the ADAQ7768-1 has an excellent device to device phase matching performance.

A high-performance ADC driver amplifier ensures the full settling of the ADC input at the maximum sampling rate. The driver circuit is designed to have minimum additive noise, error and distortion while maintaining stability. The fully differential architecture helps maximizing the signal chain dynamic range.

The to digital converter (ADC) inside the ADAQ7768-1 is a high performance, 24-bit precision, single channel Sigma-Delta converter with excellent AC performance and DC precision and the throughput rate of 256 kSPS from a 16.384 MHz MCLK.

An optional linearity boost buffer can further improve the signal chain linearity.

The ADAQ7768-1 is specified with the input reference voltage of 4.096V, but the device can support reference voltages ranging from VDD_ADC down to 1V.

The ADAQ7768-1 has two types of reference buffers. A pre-charge reference buffer to ease the reference input driving requirement or a full reference buffer to provide high impedance reference input. Both buffers are optional and can be turned off through register configuration. ADAQ7768-1 supports three clock input types: crystal, CMOS or LVDS.

Three types of digital low pass filters are available on the ADAQ7768-1. The wideband filter offers a filter profile similar to an ideal brick wall filter, making it a great fit for doing frequency analysis. The Sinc5 filter offers a low latency path with a smooth step response while maintaining a good level of aliasing rejection. It also supports an output data rate up to 1.024 MHz from a 16.384 MHz MCLK, making the Sinc5 filter ideal for low latency data capturing and time domain analysis. The Sinc3 filter supports a wide decimation ratio and can produce output data rate down to 50 SPS from a 16.384 MHz MCLK. This combined with the simultaneous 50/60Hz rejection post filter makes Sinc3 filter especially useful for precision DC measurement. All the three digital filters on the ADAQ7768-1 are FIR filters with linear phase response. The bandwidth of the filters, which directly corresponds to the bandwidth of the DAQ signal chain are fully programable through register configuration.

The ADAQ7768-1 also supports two device configuration methods. The user has the option to choose to configure the device via register write through its SPI interface, or through a simple hardware pin strapping method to configure the device to operate under a number of pre-defined modes.

A single SPI interface supports both the register access and the sample data readback functions. The ADAQ7768-1 always acts as a SPI slave. Multiple interface modes are supported with a minimum of three IO channels required to communicate with the device.

ADAQ7768-1 also features a suite of internal diagnostic functions that can detect a broad range of errors during operation to help improving the system reliability. The ADAQ7768-1 device has an operating temperature range of -40°C to +105°C and is available in a 12mm x 6mm, 84-ball BGA package with 0.8mm ball pitch. The ADAQ7768-1 utilizes only 75sq mm of board space, 10 times less than the discrete solution that utilizes 750sq mm.

Applications

• Universal input measurement platform
• Electrical Test and Measurement
• Sound and Vibration, Acoustic and Material Science R&D
• Control and Hardware in Loop Verification
• Condition monitoring for predictive maintenance
• Audio Test