w*****n
发帖数: 27 | 1 在一些paper中看到用bandgap的电路来作为其他电路的supply voltage。
我的疑惑是有时看到将bandgap的输出连到pMos的source，可是从pMOS的source看过去
的等效电阻应该和bandgap的输出电阻
相比差不了多少，这样能行吗？温度一变化，bandgap输出就不稳定了吧。 |
f*****0
发帖数: 489 | 2 think about what a bandgap is and how it works and then rethink about your
question. |
w*****n
发帖数: 27 | 3 我还是不懂，大侠能在讲明白点吗？谢谢。
【在 f*****0 的大作中提到】
: think about what a bandgap is and how it works and then rethink about your
: question.
|
c*u
发帖数: 916 | 4 bandgap的输出电阻是啥意思？温度一变化，bandgap reference 的确会变化
【在 w*****n 的大作中提到】
: 在一些paper中看到用bandgap的电路来作为其他电路的supply voltage。
: 我的疑惑是有时看到将bandgap的输出连到pMos的source，可是从pMOS的source看过去
: 的等效电阻应该和bandgap的输出电阻
: 相比差不了多少，这样能行吗？温度一变化，bandgap输出就不稳定了吧。
|
h*******y
发帖数: 896 | 5 我的疑惑是有时看到将bandgap的输出连到pMos的source，可是从pMOS的source看过去
的等效电阻应该和bandgap的输出电阻
相比差不了多少，这样能行吗？温度一变化，bandgap输出就不稳定了吧。
bandgap is buffered (LOW Rout) before it's used as supply voltage.
温度一变化，bandgap输出就不稳定了吧。
bandgap is very stable with temp, this is what it's supposed to be; if not,
the design is bad |
w*****n
发帖数: 27 | 6 我的想法是这样的：正如你所说要用一个buffer，假设buffer的输出为Rout，而负载的
等效电阻为RL，Vo为buffer的输出电压，不会随温度而变化。那么最终负载的电压应该是
VL=Vo*RL/(Rout+RL)。理想的voltage source的Rout应该是0，可是这里的Rout和RL应
该像差不大，还有RL也可能随温度而变化，这样最终的提供给负载的电压不久不稳定了
吗。
【在 h*******y 的大作中提到】
: 我的疑惑是有时看到将bandgap的输出连到pMos的source，可是从pMOS的source看过去
: 的等效电阻应该和bandgap的输出电阻
: 相比差不了多少，这样能行吗？温度一变化，bandgap输出就不稳定了吧。
: bandgap is buffered (LOW Rout) before it's used as supply voltage.
: 温度一变化，bandgap输出就不稳定了吧。
: bandgap is very stable with temp, this is what it's supposed to be; if not,
: the design is bad
|
f*****0
发帖数: 489 | 7 "VL=Vo*RL/(Rout+RL)。"
and Vl=Vo/(1+Rout/Rl).
do dVl/dRl and see what it is as Rout->0. |
f*****0
发帖数: 489 | 8
that's right. the "gap" in "bandgap" refers to the difference between two
Vbe (or Vgs in the fet world). in its simplest form, a bandgap is the
difference between two Vbe driving by two different constant current sources
. as Vbe is much more sentitive to Ibe (the current going through the
junctions) than temperature, the differential in two Vbe simply cancels out
any fluction caused by temperature.
【在 h*******y 的大作中提到】
: 我的疑惑是有时看到将bandgap的输出连到pMos的source，可是从pMOS的source看过去
: 的等效电阻应该和bandgap的输出电阻
: 相比差不了多少，这样能行吗？温度一变化，bandgap输出就不稳定了吧。
: bandgap is buffered (LOW Rout) before it's used as supply voltage.
: 温度一变化，bandgap输出就不稳定了吧。
: bandgap is very stable with temp, this is what it's supposed to be; if not,
: the design is bad
|
e***b
发帖数: 53 | 9 I never saw anyone directly uses a bandgap as power supply.
You will always need a buffer.
Actually, you are talking about a voltage regulator now.
Yes, the buffer output voltage will drift with temperature due to buffer offset drift, unless you use chopper or autozero technique. why do you have to have constant supply voltage? It is not a problem for me if supply voltage changes .Typicallly, the buffer is in feedback operation. the close loop output
impedance is much less than its open loop ou
【在 w*****n 的大作中提到】
: 在一些paper中看到用bandgap的电路来作为其他电路的supply voltage。
: 我的疑惑是有时看到将bandgap的输出连到pMos的source，可是从pMOS的source看过去
: 的等效电阻应该和bandgap的输出电阻
: 相比差不了多少，这样能行吗？温度一变化，bandgap输出就不稳定了吧。
|
e***b
发帖数: 53 | 10 Shouldn't you read some textbook first, then tell us how bandgap works?
sources
out
【在 f*****0 的大作中提到】
:
: that's right. the "gap" in "bandgap" refers to the difference between two
: Vbe (or Vgs in the fet world). in its simplest form, a bandgap is the
: difference between two Vbe driving by two different constant current sources
: . as Vbe is much more sentitive to Ibe (the current going through the
: junctions) than temperature, the differential in two Vbe simply cancels out
: any fluction caused by temperature.
|
|
|
f*****0
发帖数: 489 | 11
definitely. But textbooks are too expensive so I usually read datasheet
instead.
bandgap comes in many shapes and forms but lm113 is probably some of the
best examples on how bandgap voltage reference work.
so here it is.
can your bandgap textbooks tell us how it works? specifically, Q1/Q2/Q4 and
Q7/Q9?
it may help if you simplifies the schematic a little bit but I will leave
that to you.
【在 e***b 的大作中提到】
: Shouldn't you read some textbook first, then tell us how bandgap works?
:
: sources
: out
|
f*****0
发帖数: 489 | 12 and if your textbooks are any good, they may also explain why Q3 and Q8's
bases are tied to Q2's base, and why R1/R4's values differ. |
e***b
发帖数: 53 | 13 well, you thought you knew everything and argue with people everywhere, especially on Living board and automobile board. Actually, many of your previous posts here including this bandgap one does not make any sense.
The theory of bandgap is: with different current density through two PN junctions( the current does not have to be constant over temperature. these two current can drift with temperature. it is ok as long as the two current sources are matched), then the voltage drop on these two p
【在 f*****0 的大作中提到】
: and if your textbooks are any good, they may also explain why Q3 and Q8's
: bases are tied to Q2's base, and why R1/R4's values differ.
|
w*****n
发帖数: 27 | 14 我知道是要用buffer的。用的话是不是还要考虑到驱动的问题，因为外电路会sink
current from buffer，这样会不会影响buffer的工作状态，使之不能正常工作？
offset drift, unless you use chopper or autozero technique. why do you have
to have constant supply voltage? It is not a problem for me if supply
voltage changes .Typicallly, the buffer is in feedback operation. the close
loop output
【在 e***b 的大作中提到】
: I never saw anyone directly uses a bandgap as power supply.
: You will always need a buffer.
: Actually, you are talking about a voltage regulator now.
: Yes, the buffer output voltage will drift with temperature due to buffer offset drift, unless you use chopper or autozero technique. why do you have to have constant supply voltage? It is not a problem for me if supply voltage changes .Typicallly, the buffer is in feedback operation. the close loop output
: impedance is much less than its open loop ou
|
e***b
发帖数: 53 | 15 yes, you need to make sure it has enough driving capability, otherwise, it
could stop working under heavy load. That is a large signal concept. it has
nothing to do with the output impedance of the pmos as you asked before,
though.
have
close
【在 w*****n 的大作中提到】
: 我知道是要用buffer的。用的话是不是还要考虑到驱动的问题，因为外电路会sink
: current from buffer，这样会不会影响buffer的工作状态，使之不能正常工作？
:
: offset drift, unless you use chopper or autozero technique. why do you have
: to have constant supply voltage? It is not a problem for me if supply
: voltage changes .Typicallly, the buffer is in feedback operation. the close
: loop output
|
f*****0
发帖数: 489 | 16 "Then where does this constant current initially come from? tell me on the
picture you post, where does constant current come from?"
I am surprised that after finishing the analysis (which is correct by the
way), you still couldn't figure out that question by yourself.
lm113 is a constant voltage diode. through the banggap reference, it
maintains a constant voltage between terminal 1 and 2.
That voltage drop is also split between R1 and Q1 ('s Vbe), and R4 and Q2('s
Vbe). so the current going th |
f*****0
发帖数: 489 | 17 btw, the bandgap works without the feedback amplifier.
why do you need it then, smartie? |
f*****0
发帖数: 489 | 18
especially on Living board and automobile board.
well, smartie, here is another bandgap. try to figure out how it works.
【在 e***b 的大作中提到】
: well, you thought you knew everything and argue with people everywhere, especially on Living board and automobile board. Actually, many of your previous posts here including this bandgap one does not make any sense.
: The theory of bandgap is: with different current density through two PN junctions( the current does not have to be constant over temperature. these two current can drift with temperature. it is ok as long as the two current sources are matched), then the voltage drop on these two p
|
e***b
发帖数: 53 | 19 <<
way), you still couldn't figure out that question by yourself.>>>
You tell me where the constant current come from!
<<
maintains a constant voltage between terminal 1 and 2.>>>
lm113 is a constant voltage diode? what are you talking bout? LM113 is a bandgap reference, it is NOT just a diode. There is no such kind of stuff called constant voltage diode.
【在 f*****0 的大作中提到】
: "Then where does this constant current initially come from? tell me on the
: picture you post, where does constant current come from?"
: I am surprised that after finishing the analysis (which is correct by the
: way), you still couldn't figure out that question by yourself.
: lm113 is a constant voltage diode. through the banggap reference, it
: maintains a constant voltage between terminal 1 and 2.
: That voltage drop is also split between R1 and Q1 ('s Vbe), and R4 and Q2('s
: Vbe). so the current going th
|
e***b
发帖数: 53 | 20 Well, jerk, you tell me how it works. don't tell me those diodes are
constant voltage diode. that kind of thing does not exist at all. tell me
where that 1mA constant current come from and what is going to happen when Vs changes?
【在 f*****0 的大作中提到】
:
: especially on Living board and automobile board.
: well, smartie, here is another bandgap. try to figure out how it works.
|
|
|
e***b
发帖数: 53 | 21 To completely make you shut up, here is what Bob Pease explained how
bandgap works.
"The beauty of the band-gap reference is the summation of the Vbe term,
which decreases at the rate of about -2 millivolts /°C, and the (delta-Vbe
term) which grows at about + 2 millivolts /°C, to achieve an overall
Temperature Coefficient (Tempco) that is substantially zero. ALL band-gaps employ this summation of a growing and a shrinking voltage, to make a stable low-tempco voltage."
Again, there is no such th
【在 f*****0 的大作中提到】
: btw, the bandgap works without the feedback amplifier.
: why do you need it then, smartie?
|
f*****0
发帖数: 489 | 22 "here is what Bob Pease explained how bandgap works. "
I didn't know that you impersonate others for a living.
I didn't ask bob peace how it works. I asked you how it works.
but I guess we know the answer, smartie. |
e***b
发帖数: 53 | 23 难道Bob Pease在他的那个网页上没有这么说吗？ 难道你看不懂 Bob Pease的英文? 还是你觉得我给你的那个网页是我自己搞的，假称自己是Bob Pease?
我一点不吃惊你会继 续狡辩， 你在很多版上和很多不同的人狡辩， 这是你的一贯风格。
知之为知之，不知为不知， 真知也。古人都懂这个简单的道理。你还是不明白。在每个版面上每个问题上你都是以专家的姿态出现。
<<<: but I guess we know the answer, smartie.>>>
you should say you know the answer now! don't say WE. I knew how to design a bandgap many years ago. I designed several products with on chip bandgap. all those products had been released to the market.
<< |
f*****0
发帖数: 489 | 24
Vs changes?
I am happy to teach you how it works but smartie, where is the delta Vbe and
how does it add to Vbe to form the bandgap, jerk!
【在 e***b 的大作中提到】
: Well, jerk, you tell me how it works. don't tell me those diodes are
: constant voltage diode. that kind of thing does not exist at all. tell me
: where that 1mA constant current come from and what is going to happen when Vs changes?
|
f*****0
发帖数: 489 | 25
还是你觉得我给你的那个网页是我自己搞的，假称自己是Bob Pease?
you fairly accurately described yourself.
【在 e***b 的大作中提到】
: 难道Bob Pease在他的那个网页上没有这么说吗？ 难道你看不懂 Bob Pease的英文? 还是你觉得我给你的那个网页是我自己搞的，假称自己是Bob Pease?
: 我一点不吃惊你会继 续狡辩， 你在很多版上和很多不同的人狡辩， 这是你的一贯风格。
: 知之为知之，不知为不知， 真知也。古人都懂这个简单的道理。你还是不明白。在每个版面上每个问题上你都是以专家的姿态出现。
: <<<: but I guess we know the answer, smartie.>>>
: you should say you know the answer now! don't say WE. I knew how to design a bandgap many years ago. I designed several products with on chip bandgap. all those products had been released to the market.
: <<
|
f*****0
发帖数: 489 | 26 "That is measured by passing the amplifier output through a bandpass filter
with passband of 0.1Hz to 10Hz or 0.01Hz to 10Hz. Yes, we do use an analog
filters to do that. it works fine at this low frequency. go to take a look
at some datasheets: http://focus.ti.com/lit/ds/symlink/opa2244.pdf"
I scanned through the datasheet quickly but failed to see the superduper
filter you referrenced. and would love to see how it is constructed.
so where is it on that datasheet?
"I am not very smart."
that's |
e***b
发帖数: 53 | 27 你不停的说Widlar bandgap 的 (delta vbe /R5 ) 是恒定电流，现在你解释一下为什么这是恒定电流. (delta vbe/R5)=kT/q *ln(n)／R5, 这个电流显然和绝对温度成正比， 你不要东拉西扯，直接回答我这个问题！
不管你用什么样的bandgap结构，(delta vbe/R) 电流都是和绝对温度成正比。 利用 delta vbe 的 正温度系数 去补偿 vbe 的 负温度系数，这是bandgap的基本原理， 你连这个都不懂，还有脸在这里诡辩。 按照你的说法， Bob Pease说的 bandgap 原理是骗人的， 所有的教科书说的 bandgap 原理都是骗人的, 只有你懂，只有你说的才是真理。你狡辩的招术已经超越轮子的水平了。见过皮厚的，没见过象你这么厚颜无耻的。
你给Bob Pease 发个邮件，看看那个是不是他的网页。 你自己萎缩，以为别人和你一
样萎缩，搞个假的网页？所谓人如其名，难怪你的ID这么萎缩。
那个０.1HZ ~10Hz noise 参数你没看见？datasheet都不会看？教你怎么设计滤波器？ 象你这么蠢的，教了你, 你
【在 f*****0 的大作中提到】
: "That is measured by passing the amplifier output through a bandpass filter
: with passband of 0.1Hz to 10Hz or 0.01Hz to 10Hz. Yes, we do use an analog
: filters to do that. it works fine at this low frequency. go to take a look
: at some datasheets: http://focus.ti.com/lit/ds/symlink/opa2244.pdf"
: I scanned through the datasheet quickly but failed to see the superduper
: filter you referrenced. and would love to see how it is constructed.
: so where is it on that datasheet?
: "I am not very smart."
: that's
|
f*****0
发帖数: 489 | 28 " (delta vbe/R5)=kT/q *ln(n)／R5, 这个电流显然和绝对温度成正比， 你不要东拉
西扯，直接回答我这个问题！"
OK, you stated that the Delta Vbe has a temperature coefficient of +2mv/c.
how does the above equation show that?
"利用 delta vbe 的 正温度系数 去补偿 vbe 的 负温度系数，这是bandgap的基本原
理，"
it is one of the principles of a bandgap. or you wouldn't explain how the
two diode strings form a "bandgap".
你连这个都不懂，还有脸在这里诡辩。 "
按照你的说法， Bob Pease说的 bandgap 原理是骗人的， 所有的教科书说的 bandgap
原理都是骗人的, "
that's because of your moronic comprehension of what I said.
只有你懂， |
e***b
发帖数: 53 | 29 你不要东拉西扯，你一直坚持delta vbe／R5 是恒定电流， 你解释一下是不是恒定电流，如果是，为什么？我都问你好几次了，你就知道东扯西扯，一直解释不了。你如果解释不了，就闭上你的臭嘴。
delta vbe = kT/q*ln(n)
d(delta vbe)/dT = k/q*ln(n)
k= 1.38*10^(-23)
q= 1.6*10^(-19)
如果正确的设置Q1和 Q2 发射极 的 比例 或者 电流密度 ，让 (R4/R5)*1n(n)=２３.
188, 你自己去算一下 d(delta vbe)/dT *(R4/R5) 是不是 +２mv/C
在Widlar bandgap 中， R4/R5 是 delta vbe 的 增益. 不管你用什么结构，总是要正确的选择这个增益，让 delta vbe * gain = +2mv/ C, 因为 vbe 的温度系数大约是 －２mv/C
不管谁问什么问题,你总是以专家的姿态出来解答，尽管你连电路的基本知识都没有。象你这种蠢东西，还是滚回你的化粪池里，别在这里误导这里的年轻人，你那个FKU bandgap 理论根本就是狗屁不通。 You
【在 f*****0 的大作中提到】
: " (delta vbe/R5)=kT/q *ln(n)／R5, 这个电流显然和绝对温度成正比， 你不要东拉
: 西扯，直接回答我这个问题！"
: OK, you stated that the Delta Vbe has a temperature coefficient of +2mv/c.
: how does the above equation show that?
: "利用 delta vbe 的 正温度系数 去补偿 vbe 的 负温度系数，这是bandgap的基本原
: 理，"
: it is one of the principles of a bandgap. or you wouldn't explain how the
: two diode strings form a "bandgap".
: 你连这个都不懂，还有脸在这里诡辩。 "
: 按照你的说法， Bob Pease说的 bandgap 原理是骗人的， 所有的教科书说的 bandgap
|
w7
发帖数: 76 | 30
eejob: Looks like that you're really into the analog field. Good job for the technical part of the whole argument.
Don't know this bandgap part is still used or not today but LM10 that is designed by Bob is still being the off-the-shelf part today. |
|
|
j***j
发帖数: 324 | 31 do not need to argue anymore...
anyone who knows a little bit ic design will know who is correct,
.
电流，如果是，为什么？我都问你好几次了，你就知道东扯西扯，一直解释不了。你如
果解释不了，就闭上你的臭嘴。
正确的选择这个增益，让 delta vbe * gain = +2mv/ C, 因为 vbe 的温度系数大约是
－２mv/C
。象你这种蠢东西，还是滚回你的化粪池里，别在这里误导这里的年轻人，你那个FKU
bandgap 理论根本就是狗屁不通。 You stinky dumb ass! FKU, that is your name!
处被人骂成是神经病的蠢东西，你说的话，会有人当真吗?
【在 e***b 的大作中提到】
: 你不要东拉西扯，你一直坚持delta vbe／R5 是恒定电流， 你解释一下是不是恒定电流，如果是，为什么？我都问你好几次了，你就知道东扯西扯，一直解释不了。你如果解释不了，就闭上你的臭嘴。
: delta vbe = kT/q*ln(n)
: d(delta vbe)/dT = k/q*ln(n)
: k= 1.38*10^(-23)
: q= 1.6*10^(-19)
: 如果正确的设置Q1和 Q2 发射极 的 比例 或者 电流密度 ，让 (R4/R5)*1n(n)=２３.
: 188, 你自己去算一下 d(delta vbe)/dT *(R4/R5) 是不是 +２mv/C
: 在Widlar bandgap 中， R4/R5 是 delta vbe 的 增益. 不管你用什么结构，总是要正确的选择这个增益，让 delta vbe * gain = +2mv/ C, 因为 vbe 的温度系数大约是 －２mv/C
: 不管谁问什么问题,你总是以专家的姿态出来解答，尽管你连电路的基本知识都没有。象你这种蠢东西，还是滚回你的化粪池里，别在这里误导这里的年轻人，你那个FKU bandgap 理论根本就是狗屁不通。 You
|
w7
发帖数: 76 | 32 I still have a couple of questions here:
1. In the schematic of LM113, the collector of the far right transistor Q9
is connected to R9. But for me that looks more reasonable if the collector
of Q9 is directly hooked to the top rail "1". Q4/Q7/Q9 form a negative
feedback loop to force the voltage between "1" and "2", which is the output
voltage of this bandgap ckt. At this point, the schematic in Bob Pease'
article is as same as what I think. I can't appreciate why the Q9 is hooked
that way.
2. I
【在 e***b 的大作中提到】
: 你不要东拉西扯，你一直坚持delta vbe／R5 是恒定电流， 你解释一下是不是恒定电流，如果是，为什么？我都问你好几次了，你就知道东扯西扯，一直解释不了。你如果解释不了，就闭上你的臭嘴。
: delta vbe = kT/q*ln(n)
: d(delta vbe)/dT = k/q*ln(n)
: k= 1.38*10^(-23)
: q= 1.6*10^(-19)
: 如果正确的设置Q1和 Q2 发射极 的 比例 或者 电流密度 ，让 (R4/R5)*1n(n)=２３.
: 188, 你自己去算一下 d(delta vbe)/dT *(R4/R5) 是不是 +２mv/C
: 在Widlar bandgap 中， R4/R5 是 delta vbe 的 增益. 不管你用什么结构，总是要正确的选择这个增益，让 delta vbe * gain = +2mv/ C, 因为 vbe 的温度系数大约是 －２mv/C
: 不管谁问什么问题,你总是以专家的姿态出来解答，尽管你连电路的基本知识都没有。象你这种蠢东西，还是滚回你的化粪池里，别在这里误导这里的年轻人，你那个FKU bandgap 理论根本就是狗屁不通。 You
|
f*****0
发帖数: 489 | 33 "on page 3 at http://focus.ti.com/lit/ds/symlink/opa333.pdf
that's a nice catch! But our wizkid suggested that the opa2244 datasheet
showed that so I am still looking for it to tell me where it is in that
opa2244 datasheet. My old eyes aren't seeing it.
"NOISE
Input Voltage Noise, f = 0.01Hz to 1Hz 0.3 μVPP
Input Voltage Noise, f = 0.1Hz to 10Hz 1.1 μVPP
Input Current Noise, f = 10Hz in 100 fA/ÖHz""
those are nice figures but the datasheet gave no indication of how it is
mesured, specifical |
f*****0
发帖数: 489 | 34 "你不要东拉西扯，你一直坚持delta vbe／R5 是恒定电流，"
I am sorry but you are fighting with an imagined animal. I never said that
delta vbe / r5 is constant current. but I guess in order to win an argument
you are desparate.
"delta vbe = kT/q*ln(n)
d(delta vbe)/dT = k/q*ln(n)
k= 1.38*10^(-23)
q= 1.6*10^(-19)
如果正确的设置Q1和 Q2 发射极 的 比例 或者 电流密度 ，让 (R4/R5)*1n(n)=２３.
188, 你自己去算一下 d(delta vbe)/dT *(R4/R5) 是不是 +２mv/C"
I was commenting on your notion that delta Vbe has a tempco of +2mv/c. I
pointed out to you that delta Vbe d |
f*****0
发帖数: 489 | 35 the attached schematic may help explain how the "simple diode" bandgap works.
it is essentially an unbalanced "current mirror". I1 > I2, and Vbeq1 > Vbeq2
. so the output voltage on R3, which is the Vbe differential between Q1 and
Q2, has a much lower but positive tempco.
this is what Bob Peace referred to as the "brutal force" bandgap.
you can run the bandgap much better if you input it with constant current
over the rail, by connecting the rail to a power source with a CCS or simply
with a res |
f*****0
发帖数: 489 | 36 the widlar bandgap recognized the positive but small TC for delta Vbe and
tried out to lay it on top of a Vbe (which has a negative TC).
so the voltage drop over R2, V2=I2*R2=(delta Vbe / R3)*R2. by adjusting R2/
R3, you can give it a tempco that is "roughly" +2mv/c.
the Vout = V2+Vbe (for Q3), and by trimming R2/R3, you get a Vout that has a
0 TC.
the brokaw design is roughly the same except that it runs both legs of the
unbalanced "current mirror" at the same current - it is driven by a curren |
f*****0
发帖数: 489 | 37
output
hooked
the pease article is for simplified schematic. yes, your design would work
but having a resistor (R9) there lowered the gain of the super linear pair (
Q7/Q9) (thus improves the stability) and also limits the amount of current
that can go through Q9.
correct on both accounts.
【在 w7 的大作中提到】
: I still have a couple of questions here:
: 1. In the schematic of LM113, the collector of the far right transistor Q9
: is connected to R9. But for me that looks more reasonable if the collector
: of Q9 is directly hooked to the top rail "1". Q4/Q7/Q9 form a negative
: feedback loop to force the voltage between "1" and "2", which is the output
: voltage of this bandgap ckt. At this point, the schematic in Bob Pease'
: article is as same as what I think. I can't appreciate why the Q9 is hooked
: that way.
: 2. I
|
f*****0
发帖数: 489 | 38 "从现在开始，就当你是一堆狗屎，我看到就绕开。反正你每天吃饱了，就在网上诡辩
，难怪经常看到你在 Living board 被大家骂的狗血喷头。是很多人骂你傻逼，不是一
两人骂你。骂你的帖子太多了，就列举两个吧，你自己再去回顾一下，想想为什么大家
都忍不住会骂你傻逼。别告诉我是因为他们嫉妒你的“渊博知识”。
http://www.mitbbs.com/article/Living/31192137_0.html
http://www.mitbbs.com/article/Living/31175475_0.html"
what I hope you will understand by now is that the fact that people disagree
with you doesn't make you wrong (or right for that matter). if you think
your arguments have merits, lay them out logically and try to have a civil
discussion.
y |
h*******y
发帖数: 896 | |
f*****0
发帖数: 489 | 40
是铁证如山。
I am sorry. What did I say exactly in that post and how did it contradict
with what I said earlier?
could you please lay it out for me? |
|
|
f*****0
发帖数: 489 | 41 let me just answer one of your questions and then you will get a flavor of
how far off you are:
"3. 如果我们有一个constant current source, 那它肯定不应该随温度，power
source 变化而变化，对吧。总之，就应该总是constant, 对吧？"
what is "constant" is relative. a typical constant current source for
examples uses a series of diodes or zener or a LED to drop a "constant"
voltage off a resistor, in a fashion very similar to the widlar bandgap
topology.
in such a design, you consider the forward voltage off the diodes / zener /
led to be co |
f*****0
发帖数: 489 | 42 "That is non-sense! For many OpAmps and Instumentation Amplifiers, one
important specification is noise between 0.1Hz to 10Hz, or 0.01Hz to 10Hz.
That is measured by passing the amplifier output through a bandpass filter
with passband of 0.1Hz to 10Hz or 0.01Hz to 10Hz. Yes, we do use an analog
filters to do that. it works fine at this low frequency. go to take a look
at some datasheets: http://focus.ti.com/lit/ds/symlink/opa2244.pdf"
sorry for being persistent but where did the opa2244 datashee |
f*****0
发帖数: 489 | 43 "我问你那么多很简单的问题，怎么你就不敢回答呢？"
no reason to blow so hard like your evil twin brother blowjob (aka eejob). I
thought answering half-assed questions is quite demeaning to everyone here
so I just answered one, hoping that you would be smart enough to figoure out
the rest yourself. guess I overestimated your intelligence.
"我就觉得奇怪了，..."
no reason to be so challenged by such a simple thing. if me, a "hr lady" can
figure it out, you an blowjob can certainly figure it out.
did you take a look at the widlar c |
f*****0
发帖数: 489 | 44
wow, I never realized that your reading comprehension is so challenged.
so let me ask the question again so hopefully you will get 50% of it this
time:
where in opa2244's datasheet (that you quoted) that TI suggested a) its
noise spec for 0.1hz - 10hz, and b) its use of an analog filter for such a
spec?
since you are so challenged that I will give you until Sunday to figure out
the correct answers.
嘿。
other than blowjob and copy-and-paste, what else are you capable of? :)
but seriously, have yo |
f*****0
发帖数: 489 | 45 "3. 如果我们有一个constant current source, 那它肯定不应该随温度，power
source 变化而变化，对吧。总之，就应该总是constant, 对吧？"
since you continue to be challenged by the simple notion that what's
constant is relative, could you please allow me to help?
here is a simple link to an article by Nelson Pass (whom you undoubtedly
have never had the fortune to hear but it surfaces to say that he commands
much more authority than you do on anything electronics) on opamps.
http://www.passdiy.com/pdf/diyopamp.pdf
later in the article, Pass |
f*****0
发帖数: 489 | 46 to save you the pain of finding out what a CCS is, please take a look at the
attached.
you will notice that a) they are all quite similar in topology; and b) one
of them is identical to the widlar constant current source.
the same / similar designs are commonly accepted by those who know and used
in many highly successful and publically known designs, unlike those highly
secretive designs by a certain "bandgap" expert, :).
Class dismissed. |
f*****0
发帖数: 489 | 47
sorry for being persistent but where did the opa2244 datasheet suggest that
a) such a spec is used and b) it is measured with an analog filter?
I am still waiting for your answers, Mr. blowjob.
【在 e***b 的大作中提到】
: 你不要东拉西扯，你一直坚持delta vbe／R5 是恒定电流， 你解释一下是不是恒定电流，如果是，为什么？我都问你好几次了，你就知道东扯西扯，一直解释不了。你如果解释不了，就闭上你的臭嘴。
: delta vbe = kT/q*ln(n)
: d(delta vbe)/dT = k/q*ln(n)
: k= 1.38*10^(-23)
: q= 1.6*10^(-19)
: 如果正确的设置Q1和 Q2 发射极 的 比例 或者 电流密度 ，让 (R4/R5)*1n(n)=２３.
: 188, 你自己去算一下 d(delta vbe)/dT *(R4/R5) 是不是 +２mv/C
: 在Widlar bandgap 中， R4/R5 是 delta vbe 的 增益. 不管你用什么结构，总是要正确的选择这个增益，让 delta vbe * gain = +2mv/ C, 因为 vbe 的温度系数大约是 －２mv/C
: 不管谁问什么问题,你总是以专家的姿态出来解答，尽管你连电路的基本知识都没有。象你这种蠢东西，还是滚回你的化粪池里，别在这里误导这里的年轻人，你那个FKU bandgap 理论根本就是狗屁不通。 You
|
f*****0
发帖数: 489 | 48 "Yes, we do use an analog filters to do that. it works fine at this low
frequency. go to take a look at some datasheets: http://focus.ti.com/lit/ds/symlink/opa2244.pdf"
so Mr. Blowjob, where in the opa2244 datasheet did TI suggest that a) the
chip's noise performance in the 0.1hz - 10hz range? and b) where did TI
suggest that such performance is measured with an analog filter?
and how far along have you in understanding the patented Widlar current
source which you so forcefully disputed as inval |
