Subsection 03 Data Conversion Flashcards
A charge balancing Analogue to Digital convertor ( ADC ) uses a closed loop system to compare?
The analogue input to give the required digital output.
A Digital to Analogue convertor is required to produce an output range of 0 to -10v this can be achieved by?
An inverting OP AMP connected in series with output.
A Digital to Analogue converter would use a Precision Amplifier to?
Ensure that the output voltages remain accurate
A Digital to Analogue converter can produce 256 different output voltages, this DAC has a resolution of?
8 BITS
A DAC converts?
Digital data to Analogue signals
A DAC uses a precision amplifier to?
Ensure the output voltages remain accurate
A Digital output of Binary 1100 from a 12v Maximum Analogue to digital converter would represent a Analogue input of?
9.6v
A DAC has a resolution of 0.3v, what will be the analogue output when the digital input is 10110?
6.6v D.C.
A DAC that requires the output to range between 0 and -10v would have?
An inverting amplifier in series with the output line.
A digital voltmeter uses a?
ADC
A dual slope ADC is more prone to timing errors due to the?
Increased level of complexity
A Given transducer provides a voltage which corresponds to true heading, this voltage can be converted to “BITS” by using a?
ADC
A Ladder resistive network with reference voltage and switching system, fed to a summing amplifier could be used as a?
DAC
A Limitation of a flash ADC is?
It requires many parts
A number represented as a physical quantity e.g. voltage or speed of rotation is?
ANALOGUE
A precision op-amp is used in a DAC to?
Give an output at a required level
An ADC uses successive approximation to?
Increase speed
An ADC converts?
Analogue signals to digital data
An ADC uses successive approximation to?
Increase speed
An ADC requires?
A reference voltage, an input gate, an internal counter and a comparator.
An ADC is as accurate as?
The sampling rate.
An ADC where it counts up to binary state equal to the analogue input then back down again. When this is reached is a?
Ramp type converter.
An encoder using Grey code changes?
Analogue to digital
An input to a computer which will always require an ADC is?
A Microphone
An output from a computer that requires a DAC is a?
Speaker
An R-2R DAC has values of resistance whose precision are?
Not accurate
An R-2R DAC uses two values of resistors whose precision is?
Not important
Analogue Logic 1 is closed circuit, Logic Q = ?
1
Audio data that is stored in MP3 format will require a DAC to ?
Broadcast it in the aircraft cabin
Audio sounds recorded digitally are?
Superior quality and greater bandwidth
Digital signals can be represented?
Only as a binary value
If a signal has quantity in volts and physical position it is?
Analogue
If an ADC has a resolution of 2%, 100v might be read as
99-101v
In an Analogue to digital conversion, a signals bandwidth represents?
The maximum frequency range occupied by a signal
In an ADC the input voltage?
Stays on constantly
In a successive approximation ADC the time interval between the SC and EOC signal is?
The conversion time
In a R-2R ladder converter the values of resistors?
Do not need to be of precise value.
Op Amps generally used in ADC’s and DAC’s are normally?
Hi Input Impedance, Low Output Impedance
Physical variables in quantative forms such as voltage or angular rotation of a shaft are?
Analogue
Sample and hold is a technique used in?
Analogue to digital conversion
The accuracy of a DAC is dependant upon?
The number of BITS and type of DAC
The advantage of digital sound over analogue is?
Minimal errors and noise
The counter ( or ramp ) ADC uses a counter in conjunction with a DAC to determine the?
Equivilant to the unknown digital input voltage
The function of a commutator is to provide?
Sampling in sequence of a number of parameters
The input of a DAC is?
Digital data
The input of a ADC is?
Analogue data
The limiting factor using a resistor based DAC is?
The quality and size of resistors
The microphone in a mobile phone is an example of a?
ADC
The sampling frequency of an ADC is precisely the frequency of the AC analogue signal being measured, the output of the ADC will be a series of digital values corresponding to?
A DC signal
Transistors are used in a current triggered Digital to Analogue device to?
Change the state of the inputs
What does 1 represent in an analogue system?
Switches closed, magnetised
What is the “ throughput rate “ for the ADC?
The number of complete digital words encoded in a specified unit of time.
What is the advantage of a digital ramp type ADC over a flash type?
Digital ramp type are much cheaper to manufactuer
What is the advantage of a flash type ADC over a digital ramp type?
Flash operates at a much faster speed than digital ramp type.
What is an advantage of an R-R2 ladder DAC over a binary weight resistor?
Only 2 resistor values are used and therefore greater accuracy is achieved particular with temperature variations
What is serial to parallel and vica versa called?
Multiplex and Demultiplex
What is the quickest method of ADC?
Flash converter
What is the resolution of ADC and DAC converters?
Number of descrete values that can be represented by the digital word
What may a digital ramp ADC also be known as?
Counter type ADC
What type of ADC would be used if very high converting speeds are required?
Flash converter
What type of DAC uses a different value of resistors for each input?
Binary weighted resistor DAC
What type DAC uses two different value resistors in its construction?
R-2R ladder
When converting analogue signals to digital the resolution is determined by?
The number of BIT’s used to represent the signal
What is the fastest ADC?
Flash type
Within a computer controlled flight system, position feedback is converted from?
Analogue to digital
