10: Multivibrators
- Page ID
- 958
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)- 10.1: Digital Logic With Feedback
- This page explores gate circuits and the impact of feedback on output states. It explains how feedback leads to "latching" in OR gates and introduces multivibrator types: bistable, monostable, and astable. An example of an astable multivibrator is given, illustrating how an inverter with feedback can produce high-frequency oscillations. The significance of bistable multivibrators is emphasized for further study.
- 10.2: The S-R Latch
- This page explains the S-R latch, a bistable multivibrator with two stable states (set and reset). It highlights the importance of preventing simultaneous activation of both inputs to avoid an invalid state and mentions potential oscillations during power-up. To mitigate this, a time-delay relay can be used.
- 10.3: The Gated S-R Latch
- This page explains the enable input (E) in multivibrator circuits, which allows state changes only under specific conditions. When E is low (0), the circuit ignores S and R inputs, keeping its last state, while a high E (1) enables response to S and R. It includes practical applications like motor control circuits with a lockout feature. The enable input may be referred to as "E" or "EN."
- 10.4: The D Latch
- This page discusses the D latch, a simplified version of the gated S-R latch that replaces the R input with the inverted S input. It can change states only when the enable input is high, maintaining its previous state otherwise, which prevents illegal input states. The D latch serves as a 1-bit memory circuit, effectively storing binary values and functioning reliably in digital circuits.
- 10.5: Edge-triggered Latches- Flip-Flops
- This page covers the evolution from latch circuits to edge-triggered flip-flops, focusing on how edge-triggering enhances responsiveness during clock signal transitions. It compares standard D latches with flip-flops, explaining the importance of pulse detectors that can be built with time-delay relays or semiconductor gates. Furthermore, it notes the distinct symbols for flip-flops and latches, and discusses the aspects of positive and negative edge-triggering.
- 10.6: The J-K Flip-Flop
- This page describes the J-K flip-flop, a modified version of the S-R flip-flop that prevents invalid output states through feedback. It has J and K inputs that work together, allowing toggling of output states with high inputs and requiring clock pulses for operation. This design maintains bistability and avoids continuous toggling, differing from latches. Additionally, the block symbol simplifies its complex internal circuitry.
- 10.7: Asynchronous Flip-Flop Inputs
- This page explains the differences between synchronous and asynchronous inputs in flip-flops. It details that synchronous inputs only influence outputs during clock transitions, whereas asynchronous inputs can change the state at any time. Activating preset sets the output to Q=1, while clear resets it to Q=0, and simultaneous activation of both results in an invalid state.
- 10.8: Monostable Multivibrators
- This page covers monostable multivibrators, characterized by a stable output state changed by an external trigger, and contrasts them with bistable devices like latches and flip-flops. It explains the operation of one-shots that provide time-delayed outputs, distinguishing between retriggerable and nonretriggerable types. Applications such as debouncing switch contacts and controlling outputs are highlighted, emphasizing the significance of timing and functionality in practical circuits.