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 0V to +24V or 0V
to −24V, or a bipolar range of ±16V, 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
1pA. This allows easy input impedance matching and enables
the ADAQ7769-1 to directly interface to sensors with high output
impedance.
A fourth-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 256kSPS from a 16.384MHz 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
4.096V, 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 1.024MSPS from
a 16.384MHz 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
50SPS from a 16.384MHz MCLK. This combined with the simultaneous
50H/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. Note that, 0.1μF 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 and measurement
- Sound and Vibration, Acoustic & Material Science research and development
- Control and Hardware in loop verification
- Condition monitoring for predictive maintenance
- Audio Test
