Module 2: Flip Flops and Op Amps Flashcards
The output of a sequential circuit is determined by what?
Inputs given
present state (previous ins/outs)
Memory
What is feedback?
Outputs becoming part of the new inputs
Combinational logic circuits use what type of elements?
Decision elements
Sequential logic circuits use what type of elements?
Memory elements
What are the 2 types of sequential logic circuits?
Asynchronous and Synchronous (analyzed differently for valid outputs)
In which operation do the outputs respond to the inputs immediately and eventually reach a stable state?
Asynchronous
In synchronous operation when does the output change?
Only at specific times determined by an input control signal called a CLOCK/ENABLE
What is the reaction of a synchronous circuit to its control signal?
Static or Dynamic
When does static allow the circuit to change state?
Whenever it is high (level triggered)
When does dynamic allow the circuit to change state?
When control signal itself is changing from one level to the other
In a synchronous system, are the inputs allowed to change while the output is changing state?
No
What is the building of sequential logic
Storage elements
A bubble on a clock pulse represents what?
Negative edge trigger
An ENABLE control signal to flip flop is called what?
Latch
An SR with an enable is called?
Gated latch
What is a flip flop?
A device with 2 stable states, set (1) and reset (0)
What is a latch?
The most basic type of flip flop that stores 1 bit of info
What are the 4 basic types of flip flops?
SR, D, T, JK
What is ENABLE?
A control signal, static (level) allows circuit to change state
What is LATCH?
holds memory of last output
What is GATED?
Synchronous device using an ENABLE input
What is TOGGLE?
Changes state
What is CLOCK?
Control signal, dynamic(edge) allows circuit to change state
A latch is normally what trigger? What about the fli flop?
Latch is level triggered
Flip FLop is edge triggered
What are the 2 Asynchronous inputs?
Preset and Clear
When preset is active what happens?
Priority over all, makes output SET
When CLEAR is active, what happens?
Priority over all, makes output reset
Preset and clear are normally high or low?
Low (bubble)
What are the 3 characteristics of an Op amp?
High input impedance
Low output impedance
High voltage gain
An op amp configured to output Max voltage is driven into what?
Saturation
The op amp saturates at ______ of supply Voltage
80%
What is clipping?
When signal is driven beyond saturation
What are the 3 basic op amp configurations?
Comparator
Inverting
Summing
What does a voltage comparator do?
Compares inverting and non inverting and produces an output based on which input is more positive
What can be used as an input to an op amp which effectively zeroes the output?
Offset null
How do we get a single polarity output?
Ground one of the supply voltages
What is the purpose of the negative feedback?
Controls the gain of the device, connected from output to inverting lead
Gain levels in a closed loop are _______ than open
much lower
The high input impedance of an op amp prevents what?
Current from flowing through the op amp
In a voltage summing amp, the V out is the inverted sum of the input Vs when all the resistors are what?
The same value
