5.3 - Data Conversion Flashcards
What signals can be bipolar?
AC analogue signals
What signals can be unipolar
DC signals. They fluctuate between 0V and either a positive or negative value but Bebe alternate between both
How do digital data signals differ from analogue signals?
They only have two (binary) levels for voltage. High for on, Low for off
What is this?
Analogue to Digital Converter (ADC)
What is this?
Digital to Analogue Converter (DAC)
What does an ADC do?
It converts a continuous input voltage into a digital data stream
What are the types of of Analogue to Digital Converter (ADC)?
- Direct Comparison Converter
- Ramp Generation A/D Converter
- Successive Approximation Converter
What is the fastest type of Analogue to Digital Converter (ADC)?
The Direct Comparison Converter
How many known reference values does a DCC with 8 bit resolution have?
256 Known Values
How does a Ramp Analogue to Digital Converter (ADC) work?
It uses a binary counter to feed to a Digital to Analogue Converter (DAC).
What is the best application for a ramp generation Analogue to Digital Converter?
Works best in applications where the analogue signal level varies at a slow rate, such as a temperature sensor
What is the normal counter replaced with in a Successive Approximation Analogue to Digital Converter (ADC)?
A Successive Approximation Register (SAR)
How does a Successive Approximation Register (SAR) count?
The SAR counts by changing the bits from MSB to LSB according to input
What is a Digital to Analogue Converter?
A device that takes binary numbers, or combinations of numbers, and changes them into the corresponding voltages
How does a Digital to Analogue Converter operate?
A typical DAC converts a sequence of binary digits (Bits) into impulses, which are then processed by a reconstruction filter to smooth out the step response into continuous curves
What is one of the simplest Digital to Analogue Converter
The Binary Weighted Ladder network
How does a Digital to Analogue Converter operate?
Each bit of a binary input controls a solid state switch. The solid state switch connects either a reference voltage or grounds to a corresponding binary weighted resistor
What are the four main types of Digital to Analogue Converter circuits
- Binary weighted resistor
- Binary ladder or R-R2 ladder
- Segmented DAC
- Delta-sigma DAC
How does the ladder R-2R network DAC operate?
Each bit of the binary input controls a solid-state switch, connecting either a reference voltage or a ground to the resistors.
In an R-2R ladder network, different resistor values are used?
Only two different values
Are the resistor values in an R-2R Ladder network more or less critical than a Binary weighted ladder
In an R-2R ladder network the resistor values are not as critical as in the binary weighted ladder
