Things to avoid when using voltage regulators?
$begingroup$
My project has components that operate at 3 different voltages (9, 5 and 3.3). I would like to only deal with one power source. Is it alright to feed one 12 V power source to 3 voltage regulators? Is there a smarter way of getting everything powered from a common source? I want to avoid placing the components in series.
power-supply voltage-regulator
asked 11 hours ago
DanielPatrickDanielPatrick
161
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$endgroup$
|
show 2 more comments
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My project has components that operate at 3 different voltages (9, 5 and 3.3). I would like to only deal with one power source. Is it alright to feed one 12 V power source to 3 voltage regulators? Is there a smarter way of getting everything powered from a common source? I want to avoid placing the components in series.
power-supply voltage-regulator
asked 11 hours ago
DanielPatrickDanielPatrick
161
New contributor
DanielPatrick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
2
$begingroup$
Questions which seek a list of thoughts really don't fit the stack exchange model. You are right to realize that putting diverse loads in series is generally not workable outside of special cases given special consideration. When dropping 12v to 3.3v with a linear regulator, consider that this is only 22.5% efficient - if your load takes substantial current you will turn a lot of electricity into heat in the regulator.
$endgroup$
– Chris Stratton
11 hours ago
$begingroup$
Another issue would be if all circuits share a common ground or not.
$endgroup$
– DrMoishe Pippik
11 hours ago
$begingroup$
The PC industry has dealt with this issue long ago and standardized on feedforward tightly coupled single regulators sharing a common transformer with regulation on the main 5V supply and tight cross-regulation , load specs. But what are your specs?
$endgroup$
– Sunnyskyguy EE75
10 hours ago
$begingroup$
what wrong with having them in series to help spread the heat?
$endgroup$
– dandavis
10 hours ago
1
$begingroup$
@dandavis, "what wrong with having them in series" - it depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient).
$endgroup$
– Ale..chenski
9 hours ago
|
show 2 more comments
$begingroup$
My project has components that operate at 3 different voltages (9, 5 and 3.3). I would like to only deal with one power source. Is it alright to feed one 12 V power source to 3 voltage regulators? Is there a smarter way of getting everything powered from a common source? I want to avoid placing the components in series.
power-supply voltage-regulator
asked 11 hours ago
DanielPatrickDanielPatrick
161
New contributor
DanielPatrick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
My project has components that operate at 3 different voltages (9, 5 and 3.3). I would like to only deal with one power source. Is it alright to feed one 12 V power source to 3 voltage regulators? Is there a smarter way of getting everything powered from a common source? I want to avoid placing the components in series.
power-supply voltage-regulator
power-supply voltage-regulator
asked 11 hours ago
DanielPatrickDanielPatrick
161
New contributor
DanielPatrick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 11 hours ago
DanielPatrickDanielPatrick
161
New contributor
DanielPatrick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 11 hours ago
DanielPatrickDanielPatrick
161
New contributor
DanielPatrick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 11 hours ago
DanielPatrickDanielPatrick
161
asked 11 hours ago
DanielPatrickDanielPatrick
161
161
New contributor
DanielPatrick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
DanielPatrick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
DanielPatrick is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
2
$begingroup$
Questions which seek a list of thoughts really don't fit the stack exchange model. You are right to realize that putting diverse loads in series is generally not workable outside of special cases given special consideration. When dropping 12v to 3.3v with a linear regulator, consider that this is only 22.5% efficient - if your load takes substantial current you will turn a lot of electricity into heat in the regulator.
$endgroup$
– Chris Stratton
11 hours ago
$begingroup$
Another issue would be if all circuits share a common ground or not.
$endgroup$
– DrMoishe Pippik
11 hours ago
$begingroup$
The PC industry has dealt with this issue long ago and standardized on feedforward tightly coupled single regulators sharing a common transformer with regulation on the main 5V supply and tight cross-regulation , load specs. But what are your specs?
$endgroup$
– Sunnyskyguy EE75
10 hours ago
$begingroup$
what wrong with having them in series to help spread the heat?
$endgroup$
– dandavis
10 hours ago
1
$begingroup$
@dandavis, "what wrong with having them in series" - it depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient).
$endgroup$
– Ale..chenski
9 hours ago
|
show 2 more comments
2
$begingroup$
Questions which seek a list of thoughts really don't fit the stack exchange model. You are right to realize that putting diverse loads in series is generally not workable outside of special cases given special consideration. When dropping 12v to 3.3v with a linear regulator, consider that this is only 22.5% efficient - if your load takes substantial current you will turn a lot of electricity into heat in the regulator.
$endgroup$
– Chris Stratton
11 hours ago
$begingroup$
Another issue would be if all circuits share a common ground or not.
$endgroup$
– DrMoishe Pippik
11 hours ago
$begingroup$
The PC industry has dealt with this issue long ago and standardized on feedforward tightly coupled single regulators sharing a common transformer with regulation on the main 5V supply and tight cross-regulation , load specs. But what are your specs?
$endgroup$
– Sunnyskyguy EE75
10 hours ago
$begingroup$
what wrong with having them in series to help spread the heat?
$endgroup$
– dandavis
10 hours ago
1
$begingroup$
@dandavis, "what wrong with having them in series" - it depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient).
$endgroup$
– Ale..chenski
9 hours ago
2
2
$begingroup$
Questions which seek a list of thoughts really don't fit the stack exchange model. You are right to realize that putting diverse loads in series is generally not workable outside of special cases given special consideration. When dropping 12v to 3.3v with a linear regulator, consider that this is only 22.5% efficient - if your load takes substantial current you will turn a lot of electricity into heat in the regulator.
$endgroup$
– Chris Stratton
11 hours ago
$begingroup$
Questions which seek a list of thoughts really don't fit the stack exchange model. You are right to realize that putting diverse loads in series is generally not workable outside of special cases given special consideration. When dropping 12v to 3.3v with a linear regulator, consider that this is only 22.5% efficient - if your load takes substantial current you will turn a lot of electricity into heat in the regulator.
$endgroup$
– Chris Stratton
11 hours ago
$begingroup$
Another issue would be if all circuits share a common ground or not.
$endgroup$
– DrMoishe Pippik
11 hours ago
$begingroup$
Another issue would be if all circuits share a common ground or not.
$endgroup$
– DrMoishe Pippik
11 hours ago
$begingroup$
The PC industry has dealt with this issue long ago and standardized on feedforward tightly coupled single regulators sharing a common transformer with regulation on the main 5V supply and tight cross-regulation , load specs. But what are your specs?
$endgroup$
– Sunnyskyguy EE75
10 hours ago
$begingroup$
The PC industry has dealt with this issue long ago and standardized on feedforward tightly coupled single regulators sharing a common transformer with regulation on the main 5V supply and tight cross-regulation , load specs. But what are your specs?
$endgroup$
– Sunnyskyguy EE75
10 hours ago
$begingroup$
what wrong with having them in series to help spread the heat?
$endgroup$
– dandavis
10 hours ago
$begingroup$
what wrong with having them in series to help spread the heat?
$endgroup$
– dandavis
10 hours ago
1
1
$begingroup$
@dandavis, "what wrong with having them in series" - it depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient).
$endgroup$
– Ale..chenski
9 hours ago
$begingroup$
@dandavis, "what wrong with having them in series" - it depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient).
$endgroup$
– Ale..chenski
9 hours ago
|
show 2 more comments
2 Answers
2
active
oldest
votes
$begingroup$
The problem of having multiple voltages to different parts of design has been solved by electronics industry with so-called multi-channel PMIC - Power management IC. Here is an example from Allegro A4490:
Or Texas Instruments TPS65400:
Here is an example (from my junk box) of how the power distribution block looks in reality (Proscan 4K 40" TV), using RT6914 PMIC:
This is a fairly common solution for many classes of devices: tablet/phones, TY-sets, set-top boxes, computer monitors, you name it. This is the standard technique.
Obviously a hybrid power topology is used, some regulators are in series, some are from parallel multi-channel PMIC. It should be remembered that the power-on and power-off sequencing usually has certain timing requirements, and a all-in-one single-IC PMIC has easier means to control the sequence.
Overall the topology of regulators depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient). If you have a bunch of low-current consumers at low voltages while, say, the main power goes to 5V rail, then it is perfectly fine to have the other regulators fed from 5V rail. An example could be the "hybrid" power architecture of Intel ATOM SoC platform, Powering SoC.
answered 10 hours ago
Ale..chenskiAle..chenski
28.2k11866
$endgroup$
$begingroup$
Great answer. Thanks!
$endgroup$
– Leroy105
8 hours ago
add a comment |
$begingroup$
To address the spirit of your question, yes it is acceptable to use a 12V "Bus" as an upstream supply for "LDO" regulators. This is necessarily done in vehicle/cessel design, albeit with healthy use of opto-isolation and filtering of unconditioned inputs to circuits.
It is also common to see this on Micro Controller programming boards, where 12V, 5V, 3.3V are all required and supplied from an upstream 15V. (High voltage Programmers for Microchip/Atmel devices.)
I would not "chain" them either. Modern buck converters, if used as an assembly, will not necessarily put a lot of HF back on that supply, but a cage might be an idea.
answered 3 hours ago
mckenzmmckenzm
1373
$endgroup$
add a comment |
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2 Answers
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active
oldest
votes
2 Answers
2
active
oldest
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$begingroup$
The problem of having multiple voltages to different parts of design has been solved by electronics industry with so-called multi-channel PMIC - Power management IC. Here is an example from Allegro A4490:
Or Texas Instruments TPS65400:
Here is an example (from my junk box) of how the power distribution block looks in reality (Proscan 4K 40" TV), using RT6914 PMIC:
This is a fairly common solution for many classes of devices: tablet/phones, TY-sets, set-top boxes, computer monitors, you name it. This is the standard technique.
Obviously a hybrid power topology is used, some regulators are in series, some are from parallel multi-channel PMIC. It should be remembered that the power-on and power-off sequencing usually has certain timing requirements, and a all-in-one single-IC PMIC has easier means to control the sequence.
Overall the topology of regulators depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient). If you have a bunch of low-current consumers at low voltages while, say, the main power goes to 5V rail, then it is perfectly fine to have the other regulators fed from 5V rail. An example could be the "hybrid" power architecture of Intel ATOM SoC platform, Powering SoC.
answered 10 hours ago
Ale..chenskiAle..chenski
28.2k11866
$endgroup$
$begingroup$
Great answer. Thanks!
$endgroup$
– Leroy105
8 hours ago
add a comment |
$begingroup$
The problem of having multiple voltages to different parts of design has been solved by electronics industry with so-called multi-channel PMIC - Power management IC. Here is an example from Allegro A4490:
Or Texas Instruments TPS65400:
Here is an example (from my junk box) of how the power distribution block looks in reality (Proscan 4K 40" TV), using RT6914 PMIC:
This is a fairly common solution for many classes of devices: tablet/phones, TY-sets, set-top boxes, computer monitors, you name it. This is the standard technique.
Obviously a hybrid power topology is used, some regulators are in series, some are from parallel multi-channel PMIC. It should be remembered that the power-on and power-off sequencing usually has certain timing requirements, and a all-in-one single-IC PMIC has easier means to control the sequence.
Overall the topology of regulators depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient). If you have a bunch of low-current consumers at low voltages while, say, the main power goes to 5V rail, then it is perfectly fine to have the other regulators fed from 5V rail. An example could be the "hybrid" power architecture of Intel ATOM SoC platform, Powering SoC.
answered 10 hours ago
Ale..chenskiAle..chenski
28.2k11866
$endgroup$
$begingroup$
Great answer. Thanks!
$endgroup$
– Leroy105
8 hours ago
add a comment |
$begingroup$
The problem of having multiple voltages to different parts of design has been solved by electronics industry with so-called multi-channel PMIC - Power management IC. Here is an example from Allegro A4490:
Or Texas Instruments TPS65400:
Here is an example (from my junk box) of how the power distribution block looks in reality (Proscan 4K 40" TV), using RT6914 PMIC:
This is a fairly common solution for many classes of devices: tablet/phones, TY-sets, set-top boxes, computer monitors, you name it. This is the standard technique.
Obviously a hybrid power topology is used, some regulators are in series, some are from parallel multi-channel PMIC. It should be remembered that the power-on and power-off sequencing usually has certain timing requirements, and a all-in-one single-IC PMIC has easier means to control the sequence.
Overall the topology of regulators depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient). If you have a bunch of low-current consumers at low voltages while, say, the main power goes to 5V rail, then it is perfectly fine to have the other regulators fed from 5V rail. An example could be the "hybrid" power architecture of Intel ATOM SoC platform, Powering SoC.
answered 10 hours ago
Ale..chenskiAle..chenski
28.2k11866
$endgroup$
The problem of having multiple voltages to different parts of design has been solved by electronics industry with so-called multi-channel PMIC - Power management IC. Here is an example from Allegro A4490:
Or Texas Instruments TPS65400:
Here is an example (from my junk box) of how the power distribution block looks in reality (Proscan 4K 40" TV), using RT6914 PMIC:
This is a fairly common solution for many classes of devices: tablet/phones, TY-sets, set-top boxes, computer monitors, you name it. This is the standard technique.
Obviously a hybrid power topology is used, some regulators are in series, some are from parallel multi-channel PMIC. It should be remembered that the power-on and power-off sequencing usually has certain timing requirements, and a all-in-one single-IC PMIC has easier means to control the sequence.
Overall the topology of regulators depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient). If you have a bunch of low-current consumers at low voltages while, say, the main power goes to 5V rail, then it is perfectly fine to have the other regulators fed from 5V rail. An example could be the "hybrid" power architecture of Intel ATOM SoC platform, Powering SoC.
answered 10 hours ago
Ale..chenskiAle..chenski
28.2k11866
edited 7 hours ago
answered 10 hours ago
Ale..chenskiAle..chenski
28.2k11866
answered 10 hours ago
Ale..chenskiAle..chenski
28.2k11866
answered 10 hours ago
Ale..chenskiAle..chenski
28.2k11866
28.2k11866
$begingroup$
Great answer. Thanks!
$endgroup$
– Leroy105
8 hours ago
add a comment |
$begingroup$
Great answer. Thanks!
$endgroup$
– Leroy105
8 hours ago
$begingroup$
Great answer. Thanks!
$endgroup$
– Leroy105
8 hours ago
$begingroup$
Great answer. Thanks!
$endgroup$
– Leroy105
8 hours ago
add a comment |
$begingroup$
To address the spirit of your question, yes it is acceptable to use a 12V "Bus" as an upstream supply for "LDO" regulators. This is necessarily done in vehicle/cessel design, albeit with healthy use of opto-isolation and filtering of unconditioned inputs to circuits.
It is also common to see this on Micro Controller programming boards, where 12V, 5V, 3.3V are all required and supplied from an upstream 15V. (High voltage Programmers for Microchip/Atmel devices.)
I would not "chain" them either. Modern buck converters, if used as an assembly, will not necessarily put a lot of HF back on that supply, but a cage might be an idea.
answered 3 hours ago
mckenzmmckenzm
1373
$endgroup$
add a comment |
$begingroup$
To address the spirit of your question, yes it is acceptable to use a 12V "Bus" as an upstream supply for "LDO" regulators. This is necessarily done in vehicle/cessel design, albeit with healthy use of opto-isolation and filtering of unconditioned inputs to circuits.
It is also common to see this on Micro Controller programming boards, where 12V, 5V, 3.3V are all required and supplied from an upstream 15V. (High voltage Programmers for Microchip/Atmel devices.)
I would not "chain" them either. Modern buck converters, if used as an assembly, will not necessarily put a lot of HF back on that supply, but a cage might be an idea.
answered 3 hours ago
mckenzmmckenzm
1373
$endgroup$
add a comment |
$begingroup$
To address the spirit of your question, yes it is acceptable to use a 12V "Bus" as an upstream supply for "LDO" regulators. This is necessarily done in vehicle/cessel design, albeit with healthy use of opto-isolation and filtering of unconditioned inputs to circuits.
It is also common to see this on Micro Controller programming boards, where 12V, 5V, 3.3V are all required and supplied from an upstream 15V. (High voltage Programmers for Microchip/Atmel devices.)
I would not "chain" them either. Modern buck converters, if used as an assembly, will not necessarily put a lot of HF back on that supply, but a cage might be an idea.
answered 3 hours ago
mckenzmmckenzm
1373
$endgroup$
To address the spirit of your question, yes it is acceptable to use a 12V "Bus" as an upstream supply for "LDO" regulators. This is necessarily done in vehicle/cessel design, albeit with healthy use of opto-isolation and filtering of unconditioned inputs to circuits.
It is also common to see this on Micro Controller programming boards, where 12V, 5V, 3.3V are all required and supplied from an upstream 15V. (High voltage Programmers for Microchip/Atmel devices.)
I would not "chain" them either. Modern buck converters, if used as an assembly, will not necessarily put a lot of HF back on that supply, but a cage might be an idea.
answered 3 hours ago
mckenzmmckenzm
1373
answered 3 hours ago
mckenzmmckenzm
1373
answered 3 hours ago
mckenzmmckenzm
1373
answered 3 hours ago
mckenzmmckenzm
1373
1373
add a comment |
add a comment |
DanielPatrick is a new contributor. Be nice, and check out our Code of Conduct.
DanielPatrick is a new contributor. Be nice, and check out our Code of Conduct.
DanielPatrick is a new contributor. Be nice, and check out our Code of Conduct.
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2
$begingroup$
Questions which seek a list of thoughts really don't fit the stack exchange model. You are right to realize that putting diverse loads in series is generally not workable outside of special cases given special consideration. When dropping 12v to 3.3v with a linear regulator, consider that this is only 22.5% efficient - if your load takes substantial current you will turn a lot of electricity into heat in the regulator.
$endgroup$
– Chris Stratton
11 hours ago
$begingroup$
Another issue would be if all circuits share a common ground or not.
$endgroup$
– DrMoishe Pippik
11 hours ago
$begingroup$
The PC industry has dealt with this issue long ago and standardized on feedforward tightly coupled single regulators sharing a common transformer with regulation on the main 5V supply and tight cross-regulation , load specs. But what are your specs?
$endgroup$
– Sunnyskyguy EE75
10 hours ago
$begingroup$
what wrong with having them in series to help spread the heat?
$endgroup$
– dandavis
10 hours ago
1
$begingroup$
@dandavis, "what wrong with having them in series" - it depends on required amperage of each rail. If you need 9V@100mA and 3.3V@5A, it is uneconomical to make 9V@3A regulator before the 3.3V one (I assume switchers, even if smaller Vout/Vin ratio is somewhat more efficient).
$endgroup$
– Ale..chenski
9 hours ago