|
|
|||||||||
| Software: RF Cascade Workbook | RF Symbols for Office | RF Symbols & Stencils for Visio | Espresso Workbook | ||||||||||
|
|||||||||||||||||||||||||||||||
   |
   |
||||||||||||||||||||||||||||||
|
Please Support RF Cafe by purchasing my ridiculously low-priced products, all of which I created. RF & Electronics Symbols for Visio RF & Electronics Symbols for Office RF & Electronics Stencils for Visio T-Shirts, Mugs, Cups, Ball Caps, Mouse Pads These Are Available for Free |
|||||||||||||||||||||||||||||||
Opamp Noise Figure
These equations calculate
the noise figure of an opamp using parameters provided by vendors at the operating frequency and gain
configurations. Be sure to note units both for the input parameters and for the equations, or you will end up with
really bad results. I originally got these formulas from an engineering desk reference, but a source accessible by
everyone is "Noise Analysis for
High-Speed Op Amps," by Texas Instruments (see page 9).
VNOISE = Noise voltage density, i.e. nV/sqrt(Hz)
INOISE = Noise current density, i.e. pA/sqrt(Hz)
RS = Source resistance, i.e. 50 Ω
k = Boltzmann's Constant = 1.380 662 x 10-23 J/K
T = Ambient temperature in Kelvin
Complete Non-Inverting Opamp Noise Figure Formula (for RS = RT)
Complete Inverting Opamp Noise Figure Formula
(for RS = RT)
ENI = Input noise voltage
IBN = Non-inverting input noise current
IBI = Inverting noise current
RS = Source resistor
RT = Termination resistor
RF = Feedback resistor
RG = Gain setting resistor
Copyright: 1996 - 2026 |
About RF Cafe RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a lady's voice announced "You've Got Mail" when a new message arrived... |
Copyright 1996 - 2026 All trademarks, copyrights, patents, and other rights of ownership to images
and text used on the RF Cafe website are hereby acknowledge My Hobby Website: My Daughter's Website: |
