c*******l
发帖数: 4801 | |
W***n
发帖数: 11530 | 2 Resistance value, power rating and tolerance. What else do you need...
If you like, you may get it gold-plated, haha. |
c*******l
发帖数: 4801 | 3 ESR, ESC, temp coefficient, package, mounting method,
anything else?
【在 W***n 的大作中提到】
: Resistance value, power rating and tolerance. What else do you need...
: If you like, you may get it gold-plated, haha.
|
W***n
发帖数: 11530 | 4 As a circuit designer, I don't think we care'bout packaging. ESR is a
parameter of a capacitor. What the heck is it to do with the selection of a
resistor. ESC?! What that related to a resistor. "Temperature coefficient",
that's strange too. It's not a parameter for selecting a resistor either! |
j***j
发帖数: 324 | 5 normally, ESL is more important on selecting resistance. not 'ESR?' and 'ESC
?'...
【在 c*******l 的大作中提到】
: ESR, ESC, temp coefficient, package, mounting method,
: anything else?
|
g******u
发帖数: 3060 | 6 简单，去digikey看看有哪些电阻过滤条件就可以了。 |
W***n
发帖数: 11530 | 7
ESC
"ESL is more important on selecting resistance"?
Please elaborate.
【在 j***j 的大作中提到】
: normally, ESL is more important on selecting resistance. not 'ESR?' and 'ESC
: ?'...
|
j***j
发帖数: 324 | 8 for most sensing resistors, 'ESL' do have effects on the voltage waveforms,
some companies supply low ESL resistors for some applications.
btw: except some fab techs, normally ESL is proportional to the package of
the resistor, so smaller surface mount Rs are prefered.
【在 W***n 的大作中提到】
:
: ESC
: "ESL is more important on selecting resistance"?
: Please elaborate.
|
g*****g
发帖数: 3623 | 9 一家搞VRM MOSFET的start up，找AE
问偶
MOSFET Vgs 大于th，Ids开始导通，为什么 Vds 会维持到miller plateau才下降 我
ft
【在 c*******l 的大作中提到】
: 一个简单问题能把我老人家吓niao裤子呀！
|
c*******l
发帖数: 4801 | 10 ESL
a
",
【在 W***n 的大作中提到】
: As a circuit designer, I don't think we care'bout packaging. ESR is a
: parameter of a capacitor. What the heck is it to do with the selection of a
: resistor. ESC?! What that related to a resistor. "Temperature coefficient",
: that's strange too. It's not a parameter for selecting a resistor either!
|
|
|
c*******l
发帖数: 4801 | 11 不懂。
【在 g*****g 的大作中提到】
: 一家搞VRM MOSFET的start up，找AE
: 问偶
: MOSFET Vgs 大于th，Ids开始导通，为什么 Vds 会维持到miller plateau才下降 我
: ft
|
c*******l
发帖数: 4801 | 12 所以看着简单的问题其实都不简单
analog world里没有很简单的问题，其实
,
【在 j***j 的大作中提到】
: for most sensing resistors, 'ESL' do have effects on the voltage waveforms,
: some companies supply low ESL resistors for some applications.
: btw: except some fab techs, normally ESL is proportional to the package of
: the resistor, so smaller surface mount Rs are prefered.
|
W***n
发帖数: 11530 | 13
For DISCRETE resistors, except for very special apps, the afore-mentioned
three parameters (resistance, power rating and tolerance) should be adequate.
If you go to VLSI level, it's a totally differnet ballgame.
If you go to nano level, even more parameters'll pop up.
【在 c*******l 的大作中提到】
: 所以看着简单的问题其实都不简单
: analog world里没有很简单的问题，其实
:
: ,
|
W***n
发帖数: 11530 | 14 If I design a sensing ckt, I won't make it depends on a single absolute
precision of a single elememt. |
s*****r
发帖数: 17 | 15 This is a very standard interview question for power IC company; many times
it
starts with the loss mechanism in a switching converter and all the way to
explain the detail switching waveforms of a synchronous buck converter.
【在 g*****g 的大作中提到】
: 一家搞VRM MOSFET的start up，找AE
: 问偶
: MOSFET Vgs 大于th，Ids开始导通，为什么 Vds 会维持到miller plateau才下降 我
: ft
|
g*****g
发帖数: 3623 | 16 what else? thanks
times
【在 s*****r 的大作中提到】
: This is a very standard interview question for power IC company; many times
: it
: starts with the loss mechanism in a switching converter and all the way to
: explain the detail switching waveforms of a synchronous buck converter.
|
p*****t
发帖数: 966 | 17 价格 这才是王道 当然电阻不贵 要是电感 那就不一样了 |
x*p
发帖数: 77 | 18 很多重考虑了
主要是看应用场合
比如在一些要求高精度的地方当然要首先选择精度搞，tollerence小，温飘小的，特别
是在一些bandgap滤波器，查分放大器这种场合
但是在一些要求低noise的场合，比如前端的current amp, charge amp，这样电阻的
exess noise要求要小些
还有很多，比如要求感性较小的场合，像高频，还有一些要求容性较小的场合，还有要
求击穿等等，还有价钱也是一个重要因素
归根结底还是要看应用场合和在具体电路中的权重！
【在 c*******l 的大作中提到】
: 一个简单问题能把我老人家吓niao裤子呀！
|
c*******l
发帖数: 4801 | 19 居然把感性看成了性感，hoho
【在 x*p 的大作中提到】
: 很多重考虑了
: 主要是看应用场合
: 比如在一些要求高精度的地方当然要首先选择精度搞，tollerence小，温飘小的，特别
: 是在一些bandgap滤波器，查分放大器这种场合
: 但是在一些要求低noise的场合，比如前端的current amp, charge amp，这样电阻的
: exess noise要求要小些
: 还有很多，比如要求感性较小的场合，像高频，还有一些要求容性较小的场合，还有要
: 求击穿等等，还有价钱也是一个重要因素
: 归根结底还是要看应用场合和在具体电路中的权重！
|
s*****r
发帖数: 17 | 20 The following is limited mostly on dc-dc converters.
One of the classic interview question is about the difference between
current
mode and voltage mode control. (transfer function, artificial ramp, input
feed
forward, controller design, etc.)
Some basic non-isolated and isolated (if it is job related) converter
topology
and DC conversion ratio.
DCM and CCM operation, the difference on the transfer function
Output voltage waveform when ESR and ESL are considered, on a buck or a
boost,
CCM or DCM
【在 g*****g 的大作中提到】
: what else? thanks
:
: times
|
|
|
g*****g
发帖数: 3623 | 21 cool, thanks a lot
I am thinking jumping into VRM ...is it a fire hell???
crap...the current mode and voltage mode I was asked every time..one of them
is if too much slope compensation added, what is the effect? made it more
like VM,but about transient response.I got different opinions.
【在 s*****r 的大作中提到】
: The following is limited mostly on dc-dc converters.
: One of the classic interview question is about the difference between
: current
: mode and voltage mode control. (transfer function, artificial ramp, input
: feed
: forward, controller design, etc.)
: Some basic non-isolated and isolated (if it is job related) converter
: topology
: and DC conversion ratio.
: DCM and CCM operation, the difference on the transfer function
|
s*****r
发帖数: 17 | 22 VRM very much only refers to the module powering intel CPU, the version that
is
integrated on the mother board is called VRD. It is too much "INTEL" for me,
but of course it is just personal opinion. Also, it is not driving the power
supply technology any more. If you like high current, low voltage, POLs for
servers/network/high end graphics might be more interesting.
them
【在 g*****g 的大作中提到】
: cool, thanks a lot
: I am thinking jumping into VRM ...is it a fire hell???
: crap...the current mode and voltage mode I was asked every time..one of them
: is if too much slope compensation added, what is the effect? made it more
: like VM,but about transient response.I got different opinions.
|
d****o
发帖数: 1112 | 23 POL...expensive and not professional...
that
me,
power
for
【在 s*****r 的大作中提到】
: VRM very much only refers to the module powering intel CPU, the version that
: is
: integrated on the mother board is called VRD. It is too much "INTEL" for me,
: but of course it is just personal opinion. Also, it is not driving the power
: supply technology any more. If you like high current, low voltage, POLs for
: servers/network/high end graphics might be more interesting.
:
: them
|
s*****r
发帖数: 17 | 24 Why is POL not professional? Isn't selling expensive parts every IC company'
s
dream.
【在 d****o 的大作中提到】
: POL...expensive and not professional...
:
: that
: me,
: power
: for
|
d****o
发帖数: 1112 | 25 POL is for prototype....fast prototype
company'
【在 s*****r 的大作中提到】
: Why is POL not professional? Isn't selling expensive parts every IC company'
: s
: dream.
|
s******r
发帖数: 1439 | |
