I hate to be argumentative, but you can't be low drop out and use an
emitter follower. Draw the circuit and convince yourself. You would need
a high side driver scheme to drive the base/gate, and that require some
sort of boost converter. It can be done on switchmode chips, but not in
a linear
The Linear Technology LT3070 (150mV @ 5A) , LT3071, LT1580 , and
LT1581 (700 mV @ 10A) are examples:
http://www.linear.com/product/LT1580
For comparison:
http://www.linear.com/product/LT1584
The LT1580 (0.8V @ 7A) has the same topology as the LT1584 (1.5V @ 7A)
except everything but the pass
On Sat, 18 Feb 2012 18:59:21 -0800
Eric Lemmon wb6...@verizon.net wrote:
I hooked up a linear triple-output bench supply to run the Thunderbolt, and
now the 8040C locked up perfectly on the 1 PPS signal. Since I don't want
to tie up one of my bench power supplies to run the Thunderbolt, I
On 2/27/2012 12:48 AM, Attila Kinali wrote:
If you are really time-nutty, you can let the DC/DC converters produce
a voltage about 1V above what you need and use low noise LDOs (ie not
the 78xx or LM317 Co) to produce the voltages for the thunderbolt.
This should give you a 60-80dB damping
Having designed LDO chips, people expect them to perform miracles
well beyond reality. If you have a PNP pass and you are sitting near
dropout, you get control loops that are an ugly combination of a path
to keep the PNP from getting saturated plus one to control the
voltage.
I never
Having designed LDO chips, people expect them to perform miracles
well beyond reality. If you have a PNP pass and you are sitting near
dropout, you get control loops that are an ugly combination of a path
to keep the PNP from getting saturated plus one to control the
voltage.
I never
On Mon, 27 Feb 2012 01:29:11 -0800
gary li...@lazygranch.com wrote:
On 2/27/2012 12:48 AM, Attila Kinali wrote:
If you are really time-nutty, you can let the DC/DC converters produce
a voltage about 1V above what you need and use low noise LDOs (ie not
the 78xx or LM317 Co) to produce
-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS
Having designed LDO chips, people expect them to perform miracles
well beyond reality. If you have a PNP pass and you are sitting near
: time-nuts-boun...@febo.com
Date: Mon, 27 Feb 2012 11:23:22
To: Discussion of precise time and frequency measurementtime-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS
On Mon
-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS
Having designed LDO chips, people expect them to perform miracles
well beyond reality. If you have a PNP pass and you are sitting near
dropout, you get
...@febo.com] On
Behalf Of Attila Kinali
Sent: Monday, February 27, 2012 12:48 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS
On Sat, 18 Feb 2012 18:59:21 -0800
Eric Lemmon wb6...@verizon.net wrote:
I hooked up a linear
The PNP bipolar and P-channel MOSFET architectures do provide the
best low-dropout performance, but as I understand, do not provide the
best HF line rejection. Looking at the overall circuit - a high gain,
band-limited amplifier driving a P pass device puts it in a
common-base (or -gate) mode,
Ed wrote:
So, for best HF noise performance where the input noise may be
large, it's best to use a follower or shunt regulator topology,
despite the lower efficiency - unless efficiency is more important.
To put it more bluntly, the last time I looked (it has been a while,
so there may be
Well this is the granddaddy with 3V of dropout. Not much rejection at
high frequency, but the design is old. Modern LDOs are better,
especially with P-fet pass device.
http://www.ti.com/lit/ds/symlink/lm317-n.pdf
On 2/27/2012 9:13 PM, Charles P. Steinmetz wrote:
Ed wrote:
So, for best HF
I recently acquired a Symmetricom 8040C Rubidium Standard, hoping to use one
of my Thunderbolt GPSDOs to further refine its 10 MHz output. To my
surprise, connecting the 1 PPS output to the 8040C did nothing- the 1 PPS
SYNC indicator stayed dark. I hooked up my other Thunderbolt and got the
On Thu, 28 Apr 2011 17:04:25 -0600
Joseph Gray jg...@zianet.com wrote:
Power supply noise and ripple has been mentioned before, in relation
to OCXO's and rubidiums. So, what is considered acceptable in these
applications?
This highly depends on your system and what you want to achieve.
Just
-
From: Attila Kinali att...@kinali.ch
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Friday, April 29, 2011 11:11 AM
Subject: Re: [time-nuts] Power supply noise
On Thu, 28 Apr 2011 17:04:25 -0600
Joseph Gray jg...@zianet.com wrote:
Power supply noise
: Friday, April 29, 2011 10:35 PM
Subject: Re: [time-nuts] Power supply noise
...and I used to think batteries were a good/clean source of power. They
are better than a linear power supply... yet they make very good
temperature sensors too!
What is the perfect source of power? Clean, no ripple
Power supply noise and ripple has been mentioned before, in relation
to OCXO's and rubidiums. So, what is considered acceptable in these
applications?
Joe Gray
W5JG
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