512
問(wèn)題
CC2530-RBIAS 電阻值設(shè)置為多少依據(jù)是什么?
datasheet描述為
設(shè)置參考電流(bias resistor for reference currentreference current),,設(shè)置什么的參考電流呢?
電阻值對(duì)應(yīng)的參考電流,計(jì)算方法是什么呢? 請(qǐng)幫忙詳細(xì)說(shuō)明一下
參考設(shè)計(jì)設(shè)置是56K, why? 如果是要固定56k,??為什么不在芯片里固化呢?
為此，我還在IT官網(wǎng)問(wèn)過(guò)此問(wèn)題
TI回復(fù)及追問(wèn)：??
類似電壓電流的偏置，如果精度或者阻值有變化會(huì)對(duì)內(nèi)部電壓和電流都造成影響，芯片內(nèi)部精度達(dá)不到
不需要計(jì)算，值是固定的56K，容差1％
e2e.ti.com/.../2896984
追問(wèn)：? ? 還是沒(méi)有明白, 如何設(shè)置RBIAS 電阻值, 電阻值對(duì)應(yīng)的參考電流,計(jì)算方法是什么?請(qǐng)幫忙詳細(xì)說(shuō)明一下
TI回復(fù)：??這個(gè)值設(shè)計(jì)芯片時(shí)已經(jīng)固定了，不能更改，用戶只需要按數(shù)據(jù)手冊(cè)中的規(guī)定使用就行了
追問(wèn)：? ?數(shù)據(jù)手冊(cè), 什么都沒(méi)寫(xiě)?
datasheet描述為
我想詳細(xì)了解一下,如何設(shè)置RBIAS 電阻值, 電阻值對(duì)應(yīng)的參考電流,計(jì)算方法是什么?設(shè)置參考電流(bias resistor for reference currentreference current),,設(shè)置什么的參考電流呢?請(qǐng)幫忙詳細(xì)說(shuō)明一下
TI回復(fù)：
手冊(cè)中說(shuō)明了具體阻值
用戶只需要按要求使用規(guī)定的電阻就行了
至于計(jì)算方法和具體細(xì)節(jié)，這是芯片設(shè)計(jì)部分的問(wèn)題，我無(wú)法對(duì)此做出更多評(píng)論
老外也同樣疑惑這個(gè)問(wèn)題：
Other Parts Discussed in Thread: CC2530
RBIAS uses external resistor for internal biasing. Value in datasheet is mentioned to be 56kOhm and in application notes it is mentioned that precision resistor is required. Anyhow it is not mentioned that what tolerance is acceptable for RBIAS as using 56k resistor only for this purpose would be new part number for design and manufacturing while there would be e.g. already 56.2k used elsewhere.
TI回復(fù)如下：
Hello Janne,
The recommended tolerance on 56K bias resistor for CC2530 is ±1%.
Regards,
另一個(gè)老外 is crazy!!!
Why the RBIAS pin of the CC2530 should be connected to a 56K resistor？Why？I am crazy，HELP！
Other Parts Discussed in Thread: CC2530Why the RBIAS pin of the CC2530 should be connected to a 56K resistor？Why？
I know a base current is affected to the bias resistor，but which unit use the current？
ADC？DAC？RF？Amplifier？Comparator？
Why it is 56K，and ±1%，if not，what problem can be happen？
when use 47K or 62K，what probelm can be happen？
who can tell me？
I‘m crazy！??！
HELP！
TI回復(fù)：
Hi,
The RBIAS on all of our CC devices is used by an internal current source to setup a reference for the all analog circuits inside the device. If you change the value that we recommend the chip might not work at all. You need to use a 1% resistor and the value we use on that location. Furthermore you need to make sure there are no noise sources close to it as it will negatively influence the entire chip performance.
I would kindly recommend, next time you generate a post on this forum, to keep the discussion and the wording on purely technical terms and subjects.
The use of certain sentences may discourage people in the e2e community from helping you.
Thanks for your understanding.
TheDarkSide
兩個(gè)老外問(wèn)內(nèi)容，與我一樣，大致意思，也和我問(wèn)的一樣的，得到答案也一樣，按參考設(shè)計(jì)，不要問(wèn)為什么。
最終結(jié)論：
無(wú)解，按規(guī)定用56K電阻, no why, 難怪老外會(huì) crazzy
