topic Re: DB problem of 2874 in Digital Signal Controllers https://community.nxp.com/t5/Digital-Signal-Controllers/DB-problem-of-2874/m-p/1025721#M1815 <HTML><HEAD></HEAD><BODY><P>This noise calculation is not correct. The noise contribution of the second stage amplifier is divided by the second stage gain.</P><P></P><P>Please, see NF calculation formula in this document:<BR /><A href="https://www.nxp.com/docs/en/white-paper/RFLNAWP.pdf" target="test_blank">https://www.nxp.com/docs/en/white-paper/RFLNAWP.pdf</A></P><P></P><P>NFsys = 0.5dB + 3.5dB@G=30dB = 0.505dB</P><P></P><P>Have a great day,</P><P></P><P>Pavel<BR />TIC</P><P></P><P>&nbsp;</P><P></P><P>-------------------------------------------------------------------------------<BR />Note:<BR />- If this post answers your question, please click the "Mark Correct" button. Thank you!</P><P></P><P>&nbsp;</P><P></P><P>- We are following threads for 7 weeks after the last post, later replies are ignored<BR />Please open a new thread and refer to the closed one, if you have a related question at a later point in time.<BR />-------------------------------------------------------------------------------</P></BODY></HTML> Fri, 17 Jan 2020 11:52:29 GMT LPP 2020-01-17T11:52:29Z DB problem of 2874 https://community.nxp.com/t5/Digital-Signal-Controllers/DB-problem-of-2874/m-p/1025720#M1814 <HTML><HEAD></HEAD><BODY><P><STRONG><span class="lia-inline-image-display-wrapper" image-alt="微信图片_20191229130440.jpg"><img src="https://community.nxp.com/t5/image/serverpage/image-id/99667iEC5E84F894990923/image-size/large?v=v2&amp;px=999" role="button" title="微信图片_20191229130440.jpg" alt="微信图片_20191229130440.jpg" /></span>BGA2874</STRONG><SPAN style="color: #333333; text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: arial, 'pingfang sc', stheiti, 'microsoft yahei', sans-serif; font-size: 20px; font-style: normal; font-weight: 400; word-spacing: 0px; float: none; display: inline !important; white-space: pre-line; orphans: 2; widows: 2; background-color: #fcfcfc; text-decoration-color: initial; font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial;">Adjust to the voltage of 2.5V, 18 mA is almost 10 DB worse.</SPAN></P><P><SPAN style="color: #333333; text-transform: none; text-indent: 0px; letter-spacing: normal; font-family: arial, 'pingfang sc', stheiti, 'microsoft yahei', sans-serif; font-size: 20px; font-style: normal; font-weight: 400; word-spacing: 0px; float: none; display: inline !important; white-space: pre-line; orphans: 2; widows: 2; background-color: #fcfcfc; text-decoration-color: initial; font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial;">The two tubes on the graph add up to noise, right？</SPAN></P></BODY></HTML> Sun, 29 Dec 2019 05:32:06 GMT https://community.nxp.com/t5/Digital-Signal-Controllers/DB-problem-of-2874/m-p/1025720#M1814 1318910567 2019-12-29T05:32:06Z Re: DB problem of 2874 https://community.nxp.com/t5/Digital-Signal-Controllers/DB-problem-of-2874/m-p/1025721#M1815 <HTML><HEAD></HEAD><BODY><P>This noise calculation is not correct. The noise contribution of the second stage amplifier is divided by the second stage gain.</P><P></P><P>Please, see NF calculation formula in this document:<BR /><A href="https://www.nxp.com/docs/en/white-paper/RFLNAWP.pdf" target="test_blank">https://www.nxp.com/docs/en/white-paper/RFLNAWP.pdf</A></P><P></P><P>NFsys = 0.5dB + 3.5dB@G=30dB = 0.505dB</P><P></P><P>Have a great day,</P><P></P><P>Pavel<BR />TIC</P><P></P><P>&nbsp;</P><P></P><P>-------------------------------------------------------------------------------<BR />Note:<BR />- If this post answers your question, please click the "Mark Correct" button. Thank you!</P><P></P><P>&nbsp;</P><P></P><P>- We are following threads for 7 weeks after the last post, later replies are ignored<BR />Please open a new thread and refer to the closed one, if you have a related question at a later point in time.<BR />-------------------------------------------------------------------------------</P></BODY></HTML> Fri, 17 Jan 2020 11:52:29 GMT https://community.nxp.com/t5/Digital-Signal-Controllers/DB-problem-of-2874/m-p/1025721#M1815 LPP 2020-01-17T11:52:29Z