Multiple Step-Down Voltage Rails from a single DC Power Supply
I have one working PCB which has three different Voltage Rails
: 3.3V
, 4V
and 1.8V
. They are generated using three separate step-down
buck converters. The input voltage to all the converters is a single DC Power Supply (12V).
- Buck Converter Generating 4V powers 4G LTE Module (Load 2.5A)
- Buck Converter generating 1.8V powers LoRa IC
SX1301
(Load 1A) - Buck Converter generating 3.3V powers
iMX6ULL
System-on-module (Load: 3A)
These three different buck converters are occupying alot of PCB space and increasing the BOM
. I am thinking to implement single IC
solution for my system. A quick google search landed me on two solutions.
- A Triple Step-Down Converter from
TI
(TPS6526x) - Using a single Buck Converter to generate multiple voltages. (The link is over here).
What should I consider? Is there any different solution other than listed above?
EDIT:
The LoRaWAN IC is SX1301 and it requires 1.8V power supply.
power-supply voltage-regulator circuit-design switch-mode-power-supply buck
add a comment |
I have one working PCB which has three different Voltage Rails
: 3.3V
, 4V
and 1.8V
. They are generated using three separate step-down
buck converters. The input voltage to all the converters is a single DC Power Supply (12V).
- Buck Converter Generating 4V powers 4G LTE Module (Load 2.5A)
- Buck Converter generating 1.8V powers LoRa IC
SX1301
(Load 1A) - Buck Converter generating 3.3V powers
iMX6ULL
System-on-module (Load: 3A)
These three different buck converters are occupying alot of PCB space and increasing the BOM
. I am thinking to implement single IC
solution for my system. A quick google search landed me on two solutions.
- A Triple Step-Down Converter from
TI
(TPS6526x) - Using a single Buck Converter to generate multiple voltages. (The link is over here).
What should I consider? Is there any different solution other than listed above?
EDIT:
The LoRaWAN IC is SX1301 and it requires 1.8V power supply.
power-supply voltage-regulator circuit-design switch-mode-power-supply buck
Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
– Michael
2 days ago
Sorry. The IC is SX1301.
– abhiarora
2 days ago
1
The single point option for all three power supply using TI webbench works, as long as you use all the components mentioned in their BOM..only problem I find is if the IC fails, all three power lines will go for a toss as also pointed out in one of the answers. Do look deeply for Reliabilty of IC, along with operating temperatures when you go for full load.
– AKR
2 days ago
add a comment |
I have one working PCB which has three different Voltage Rails
: 3.3V
, 4V
and 1.8V
. They are generated using three separate step-down
buck converters. The input voltage to all the converters is a single DC Power Supply (12V).
- Buck Converter Generating 4V powers 4G LTE Module (Load 2.5A)
- Buck Converter generating 1.8V powers LoRa IC
SX1301
(Load 1A) - Buck Converter generating 3.3V powers
iMX6ULL
System-on-module (Load: 3A)
These three different buck converters are occupying alot of PCB space and increasing the BOM
. I am thinking to implement single IC
solution for my system. A quick google search landed me on two solutions.
- A Triple Step-Down Converter from
TI
(TPS6526x) - Using a single Buck Converter to generate multiple voltages. (The link is over here).
What should I consider? Is there any different solution other than listed above?
EDIT:
The LoRaWAN IC is SX1301 and it requires 1.8V power supply.
power-supply voltage-regulator circuit-design switch-mode-power-supply buck
I have one working PCB which has three different Voltage Rails
: 3.3V
, 4V
and 1.8V
. They are generated using three separate step-down
buck converters. The input voltage to all the converters is a single DC Power Supply (12V).
- Buck Converter Generating 4V powers 4G LTE Module (Load 2.5A)
- Buck Converter generating 1.8V powers LoRa IC
SX1301
(Load 1A) - Buck Converter generating 3.3V powers
iMX6ULL
System-on-module (Load: 3A)
These three different buck converters are occupying alot of PCB space and increasing the BOM
. I am thinking to implement single IC
solution for my system. A quick google search landed me on two solutions.
- A Triple Step-Down Converter from
TI
(TPS6526x) - Using a single Buck Converter to generate multiple voltages. (The link is over here).
What should I consider? Is there any different solution other than listed above?
EDIT:
The LoRaWAN IC is SX1301 and it requires 1.8V power supply.
power-supply voltage-regulator circuit-design switch-mode-power-supply buck
power-supply voltage-regulator circuit-design switch-mode-power-supply buck
edited 2 days ago
StainlessSteelRat
3,196617
3,196617
asked Dec 29 '18 at 17:51
abhiarora
440416
440416
Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
– Michael
2 days ago
Sorry. The IC is SX1301.
– abhiarora
2 days ago
1
The single point option for all three power supply using TI webbench works, as long as you use all the components mentioned in their BOM..only problem I find is if the IC fails, all three power lines will go for a toss as also pointed out in one of the answers. Do look deeply for Reliabilty of IC, along with operating temperatures when you go for full load.
– AKR
2 days ago
add a comment |
Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
– Michael
2 days ago
Sorry. The IC is SX1301.
– abhiarora
2 days ago
1
The single point option for all three power supply using TI webbench works, as long as you use all the components mentioned in their BOM..only problem I find is if the IC fails, all three power lines will go for a toss as also pointed out in one of the answers. Do look deeply for Reliabilty of IC, along with operating temperatures when you go for full load.
– AKR
2 days ago
Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
– Michael
2 days ago
Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
– Michael
2 days ago
Sorry. The IC is SX1301.
– abhiarora
2 days ago
Sorry. The IC is SX1301.
– abhiarora
2 days ago
1
1
The single point option for all three power supply using TI webbench works, as long as you use all the components mentioned in their BOM..only problem I find is if the IC fails, all three power lines will go for a toss as also pointed out in one of the answers. Do look deeply for Reliabilty of IC, along with operating temperatures when you go for full load.
– AKR
2 days ago
The single point option for all three power supply using TI webbench works, as long as you use all the components mentioned in their BOM..only problem I find is if the IC fails, all three power lines will go for a toss as also pointed out in one of the answers. Do look deeply for Reliabilty of IC, along with operating temperatures when you go for full load.
– AKR
2 days ago
add a comment |
2 Answers
2
active
oldest
votes
The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.
Where to start for magnetics of single switching stage?
– abhiarora
2 days ago
2
Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
– Simon Richter
2 days ago
add a comment |
There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.
You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.
If you have the skills then you will have at least a 1 page list of all specs.
If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.
Where to start for magnetics of single switching stage?
– abhiarora
2 days ago
2
Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
– Simon Richter
2 days ago
add a comment |
The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.
Where to start for magnetics of single switching stage?
– abhiarora
2 days ago
2
Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
– Simon Richter
2 days ago
add a comment |
The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.
The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.
answered 2 days ago
AnalogKid
1,49325
1,49325
Where to start for magnetics of single switching stage?
– abhiarora
2 days ago
2
Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
– Simon Richter
2 days ago
add a comment |
Where to start for magnetics of single switching stage?
– abhiarora
2 days ago
2
Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
– Simon Richter
2 days ago
Where to start for magnetics of single switching stage?
– abhiarora
2 days ago
Where to start for magnetics of single switching stage?
– abhiarora
2 days ago
2
2
Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
– Simon Richter
2 days ago
Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
– Simon Richter
2 days ago
add a comment |
There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.
You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.
If you have the skills then you will have at least a 1 page list of all specs.
If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
add a comment |
There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.
You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.
If you have the skills then you will have at least a 1 page list of all specs.
If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
add a comment |
There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.
You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.
If you have the skills then you will have at least a 1 page list of all specs.
If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.
You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.
If you have the skills then you will have at least a 1 page list of all specs.
If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
answered 2 days ago
Tony EE rocketscientist
62.1k22193
62.1k22193
add a comment |
add a comment |
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Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
– Michael
2 days ago
Sorry. The IC is SX1301.
– abhiarora
2 days ago
1
The single point option for all three power supply using TI webbench works, as long as you use all the components mentioned in their BOM..only problem I find is if the IC fails, all three power lines will go for a toss as also pointed out in one of the answers. Do look deeply for Reliabilty of IC, along with operating temperatures when you go for full load.
– AKR
2 days ago