The ADAQ7769-1 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 ADAQ7769-1 consists of:

• A low noise, low bias current, high bandwidth programmable gain amplifier (PGA) that can be programmed to operate at binary gains of 1 to 128
• A fourth order, low noise, linear phase anti-aliasing filter (AAF)
• A low noise, low distortion, high bandwidth, gain-selectable 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
• Reference buffer
• Critical passive components required for the signal chain

The ADAQ7769-1 supports a wide range of single-ended input amplitudes, with a maximum unipolar range of 0 V to +24 V or 0 to −24 V, or a bipolar range of ±12.5 V, basing its flexibility on the PGA supply voltages. With eight programmable binary PGA gain settings and three pin-selectable AAF gain settings, ADAQ7769-1 offers additional system dynamic range and improved signal chain noise performance with input signals of lower amplitude. The input signal is fully buffered with very low typical input bias current of 5 pA. This allows easy input impedance matching and enables the ADAQ7769-1 to directly interface to sensors with high output impedance.

A 4th order low-pass analog 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 analog low pass filter is carefully designed to achieve high phase linearity and maximum in-band magnitude response flatness. Constructed with iPASSIVES™ technology, the resistor network used within the analog 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 ADAQ7769-1 has a tight phase mismatch across devices.

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 analog to digital converter (ADC) inside the ADAQ7769-1 is a high performance, 24-bit precision, single channel Sigma-Delta converter with excellent AC performance and DC precision and a throughput rate of 256 kSPS from a 16.384 MHz MCLK. It includes an optional linearity boost buffer that can further improve the signal chain linearity.

The ADAQ7769-1 is specified with the input reference voltage of 4.096 V, but the device can support reference voltages ranging from VDD_ADC down to 1 V.

The ADAQ7769-1 has two types of reference buffers. A precharge 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.

ADAQ7769-1 supports three clock input types: crystal, CMOS or LVDS.

Three types of digital low pass filters are available on the ADAQ7769-1. The wideband low ripple FIR filter has a filter profile similar to an ideal brick wall filter, making it a great fit for doing frequency analysis. The Sinc5 filter has a low latency path with a smooth step response while maintaining a good level of aliasing rejection. It supports an output data rate up to 1.024 MSPS 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 ADAQ7769-1 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 programmable through register configuration.

The ADAQ7769-1 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 ADAQ7769-1 always acts as a SPI slave. Multiple interface modes are supported with a minimum of three IO channels required to communicate with the device.

ADAQ7769-1 features a suite of internal diagnostic functions that can detect a broad range of errors during operation to help improving the system reliability.

The ADAQ7769-1 supply connections can be greatly simplified by using its internal LDO. 0.1 uF decoupling capacitors are also integrated to further reduce the number of discrete components. On power standby, each functional block of the device can be put into standby mode. This enables the device to have a total power consumption less than TBD mW.

The ADAQ7769-1 device has an operating temperature range of −40°C to +105°C and is available in a 12 mm x 6 mm, 84-ball BGA package with 0.8mm ball pitch, making it suitable for multiple-channel applications. The footprint of the device is eleven times smaller compared to the footprint of the same solution using discrete components.

APPLICATIONS

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