Rise time Totally Explained

Everything about Rise Time totally explained

In electronics, when describing a voltage or current step function, rise time (also risetime) refers to the time required for a signal to change from a specified low value to a specified high value. Typically, these values are 10% and 90% of the step height. The output signal of a system is characterized also by fall time: both parameters depend on rise and fall times of input signal and on the characteristics of the system.

Overview

Rise time is an analog parameter of fundamental importance in high speed electronics, since it's a measure of the ability of a circuit to respond to fast input signals. Many efforts over the years have been made to reduce the rise times of generators, analog and digital circuits, measuring and data transmission equipment, focused on the research of faster electron devices and on techniques of reduction of stray circuit parameters (mainly capacitances and inductances). For applications outside the realm of high speed electronics, long (compared to the attainable state of the art) rise times are sometimes desirable: examples are the dimming of a light, where a longer rise-time results, amongst other things, in a longer life for the bulb, or digital signals apt to the control of analog ones, where a longer rise time means lower capacitive feedthough, and thus lower coupling noise.

Simple examples of calculation of rise time

The aim of this section is the calculation of rise time of step response for some simple systems: all notations and assumptions required for the following analysis are listed here.

$t_r,$ is the rise time of the analyzed system, measured in seconds.

f_L,

is the low frequency cutoff (-3 dB point) of the analyzed system, measured in hertz.

f_H,

is high frequency cutoff (-3 dB point) of the analyzed system, measured in hertz.

h(t),

is the impulse response of the analyzed system in the time domain.

H(omega),

is the frequency response of the analyzed system in the frequency domain.

The bandwidth is defined as ť

BW = f_ 
ight )

where ζ is the damping ratio and ω_n is the natural frequency of the network.

Further Information

Get more info on 'Rise Time'.

External Link Exchanges

Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:

<a href="http://rise_time.totallyexplained.com">Rise time Totally Explained</a>

Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned.