Low voltage shutdown with regulator using microcontrollerTL431 Low battery cut-offLDO with low-voltage cutoff?Is it safe to apply higher voltage to the output of a MIC2920A voltage regulator?Setting a part's VCC slightly lower than board's supply voltageSoft latch switch seems incompatible with boost voltage regulatorCan a linear regulator in shutdown mode have the output in parallel with a switching regulatorPower circuit design logic — suggestionWhat is a good voltage regulator or voltage regulating circuit for my micro-USB battery charging needs?Best way to turn off switching regulator and conserve powerSimpler way to enable/disable voltage regulator using DC jack shunt as a switch?Capacitors with an LDO voltage regulator - how necessary is it?Voltage regulator outputs some voltage even if in shutdown
Do copyright notices need to be placed at the beginning of a file?
Who knighted this character?
Dad jokes are fun
...And they were stumped for a long time
How can I properly write this equation in Latex?
Removing the last element of a list
The Most Powerful Number
Why was this character made Grand Maester?
Why does the hash of infinity have the digits of π?
Storing voxels for a voxel Engine in C++
Are runways booked by airlines to land their planes?
Can a UK national work as a paid shop assistant in the USA?
How does the Earth's center produce heat?
How to deceive the MC
Navigating a quick return to previous employer
Finding all files with a given extension whose base name is the name of the parent directory
Why is the Eisenstein ideal paper so great?
How did NASA Langley end up with the first 737?
How to melt snow without fire or using body heat?
Using too much dialogue?
Cardio work for Muay Thai fighters
On San Andreas Speedruns, why do players blow up the Picador in the mission Ryder?
What is the difference between LORD and GOD?
How to respond to an e-mail asking me to suggest a doctoral research topic?
Low voltage shutdown with regulator using microcontroller
TL431 Low battery cut-offLDO with low-voltage cutoff?Is it safe to apply higher voltage to the output of a MIC2920A voltage regulator?Setting a part's VCC slightly lower than board's supply voltageSoft latch switch seems incompatible with boost voltage regulatorCan a linear regulator in shutdown mode have the output in parallel with a switching regulatorPower circuit design logic — suggestionWhat is a good voltage regulator or voltage regulating circuit for my micro-USB battery charging needs?Best way to turn off switching regulator and conserve powerSimpler way to enable/disable voltage regulator using DC jack shunt as a switch?Capacitors with an LDO voltage regulator - how necessary is it?Voltage regulator outputs some voltage even if in shutdown
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;
$begingroup$
I'm using a lithium polymer battery with an LDO regulator. I want the regulator to shut down when the battery voltage gets too low. I'd prefer to monitor the battery voltage using a microcontroller that's already in my circuit rather than adding a separate voltage supervisor or comparator to control the regulator's Enable pin.
The problem is that the microcontroller is powered by the regulator's output VDD, so before the regulator is enabled, the microcontroller is off and its GPIO pin can't control the Enable pin. The battery's on/off switch is an SPDT switch and not momentary. Is there a solution to this that would "cost less" than adding a voltage supervisor/comparator to control the regulator's enable pin? And not adding a momentary switch? I know this won't work:
voltage-regulator
$endgroup$
add a comment |
$begingroup$
I'm using a lithium polymer battery with an LDO regulator. I want the regulator to shut down when the battery voltage gets too low. I'd prefer to monitor the battery voltage using a microcontroller that's already in my circuit rather than adding a separate voltage supervisor or comparator to control the regulator's Enable pin.
The problem is that the microcontroller is powered by the regulator's output VDD, so before the regulator is enabled, the microcontroller is off and its GPIO pin can't control the Enable pin. The battery's on/off switch is an SPDT switch and not momentary. Is there a solution to this that would "cost less" than adding a voltage supervisor/comparator to control the regulator's enable pin? And not adding a momentary switch? I know this won't work:
voltage-regulator
$endgroup$
$begingroup$
First, ADC_IN is unlikely to be capable of taking a voltage higher than your VDD, if you're lucky a protection diode will end up powering your VDD net, if you're unlucky it will ruin your microcontroller. I'd advise you to use a voltage divider to monitor 1/2 battery voltage or some fraction of the battery voltage that's less than VDD.
$endgroup$
– Andrew Macrae
5 hours ago
$begingroup$
Would be a LDO with undervoltage lockout be an option for you?
$endgroup$
– Christian B.
4 hours ago
1
$begingroup$
@Andrew yes good point...@Christian I don't see any LDO that has an undervoltage lockout at the voltage I want (about 3V)...it's surprising to me that there's no regulator that shuts down around 3V to prevent overdischarge of lithium ion/polymer batteries.
$endgroup$
– donut
4 hours ago
add a comment |
$begingroup$
I'm using a lithium polymer battery with an LDO regulator. I want the regulator to shut down when the battery voltage gets too low. I'd prefer to monitor the battery voltage using a microcontroller that's already in my circuit rather than adding a separate voltage supervisor or comparator to control the regulator's Enable pin.
The problem is that the microcontroller is powered by the regulator's output VDD, so before the regulator is enabled, the microcontroller is off and its GPIO pin can't control the Enable pin. The battery's on/off switch is an SPDT switch and not momentary. Is there a solution to this that would "cost less" than adding a voltage supervisor/comparator to control the regulator's enable pin? And not adding a momentary switch? I know this won't work:
voltage-regulator
$endgroup$
I'm using a lithium polymer battery with an LDO regulator. I want the regulator to shut down when the battery voltage gets too low. I'd prefer to monitor the battery voltage using a microcontroller that's already in my circuit rather than adding a separate voltage supervisor or comparator to control the regulator's Enable pin.
The problem is that the microcontroller is powered by the regulator's output VDD, so before the regulator is enabled, the microcontroller is off and its GPIO pin can't control the Enable pin. The battery's on/off switch is an SPDT switch and not momentary. Is there a solution to this that would "cost less" than adding a voltage supervisor/comparator to control the regulator's enable pin? And not adding a momentary switch? I know this won't work:
voltage-regulator
voltage-regulator
asked 5 hours ago
donutdonut
8319
8319
$begingroup$
First, ADC_IN is unlikely to be capable of taking a voltage higher than your VDD, if you're lucky a protection diode will end up powering your VDD net, if you're unlucky it will ruin your microcontroller. I'd advise you to use a voltage divider to monitor 1/2 battery voltage or some fraction of the battery voltage that's less than VDD.
$endgroup$
– Andrew Macrae
5 hours ago
$begingroup$
Would be a LDO with undervoltage lockout be an option for you?
$endgroup$
– Christian B.
4 hours ago
1
$begingroup$
@Andrew yes good point...@Christian I don't see any LDO that has an undervoltage lockout at the voltage I want (about 3V)...it's surprising to me that there's no regulator that shuts down around 3V to prevent overdischarge of lithium ion/polymer batteries.
$endgroup$
– donut
4 hours ago
add a comment |
$begingroup$
First, ADC_IN is unlikely to be capable of taking a voltage higher than your VDD, if you're lucky a protection diode will end up powering your VDD net, if you're unlucky it will ruin your microcontroller. I'd advise you to use a voltage divider to monitor 1/2 battery voltage or some fraction of the battery voltage that's less than VDD.
$endgroup$
– Andrew Macrae
5 hours ago
$begingroup$
Would be a LDO with undervoltage lockout be an option for you?
$endgroup$
– Christian B.
4 hours ago
1
$begingroup$
@Andrew yes good point...@Christian I don't see any LDO that has an undervoltage lockout at the voltage I want (about 3V)...it's surprising to me that there's no regulator that shuts down around 3V to prevent overdischarge of lithium ion/polymer batteries.
$endgroup$
– donut
4 hours ago
$begingroup$
First, ADC_IN is unlikely to be capable of taking a voltage higher than your VDD, if you're lucky a protection diode will end up powering your VDD net, if you're unlucky it will ruin your microcontroller. I'd advise you to use a voltage divider to monitor 1/2 battery voltage or some fraction of the battery voltage that's less than VDD.
$endgroup$
– Andrew Macrae
5 hours ago
$begingroup$
First, ADC_IN is unlikely to be capable of taking a voltage higher than your VDD, if you're lucky a protection diode will end up powering your VDD net, if you're unlucky it will ruin your microcontroller. I'd advise you to use a voltage divider to monitor 1/2 battery voltage or some fraction of the battery voltage that's less than VDD.
$endgroup$
– Andrew Macrae
5 hours ago
$begingroup$
Would be a LDO with undervoltage lockout be an option for you?
$endgroup$
– Christian B.
4 hours ago
$begingroup$
Would be a LDO with undervoltage lockout be an option for you?
$endgroup$
– Christian B.
4 hours ago
1
1
$begingroup$
@Andrew yes good point...@Christian I don't see any LDO that has an undervoltage lockout at the voltage I want (about 3V)...it's surprising to me that there's no regulator that shuts down around 3V to prevent overdischarge of lithium ion/polymer batteries.
$endgroup$
– donut
4 hours ago
$begingroup$
@Andrew yes good point...@Christian I don't see any LDO that has an undervoltage lockout at the voltage I want (about 3V)...it's surprising to me that there's no regulator that shuts down around 3V to prevent overdischarge of lithium ion/polymer batteries.
$endgroup$
– donut
4 hours ago
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
A supervisory/comparator or circuit is required if you want to do LDO enable control. One other option are LDO's with undervoltage lockouts which essentially have a comparator built in. Like the one in this question.
LDO with low-voltage cutoff?
Your right, you can't use a microcontroler to do undervoltage control, because it needs voltage to run. You need an external circuit. Another option is to use a pmosfet to do the control, which doesn't require a comparator.
$endgroup$
$begingroup$
Interestingly, I can't find an LDO that has an undervoltage lockout threshold at about 3V, which is a desired threshold to prevent overdischarge of a lithium ion/polymer battery.
$endgroup$
– donut
3 hours ago
$begingroup$
Look for LDO's with a UVLO pin, this one hase a settable range: mouser.com/new/Analog-Devices/adi-adp7104-regulators
$endgroup$
– laptop2d
2 hours ago
add a comment |
$begingroup$
I like this problem and it's kinda common to see something like it where an enable has to be constructed from a set of input signals.
Obviously your microcontroller can establish a PWR_Run signal from it's GPIO output, but it can't do that all the time. You should decide under what other conditions you want your LDO to turn on and stay on, and then build an or gate out of diodes and resistors.
My first thought would be to sense the rising edge of the input to the LDO as it's connected to VIN using a capacitor and an RC filter to let it turn on for a moment as the switch is connected and setting up the GPIO pin. As VIN charges the LDO input it will also charge EN starting everything up. Then before the resistor pulls the value of EN down to below the turnon threshold the microcontroller can assert GPIO keeping it high until the switch is turned off.
simulate this circuit – Schematic created using CircuitLab
$endgroup$
$begingroup$
Depending on the microprocessor GPIO circuitry, the regulator may never turn on because P1 might be at high impedance at power off.
$endgroup$
– laptop2d
4 hours ago
add a comment |
Your Answer
StackExchange.ifUsing("editor", function ()
return StackExchange.using("schematics", function ()
StackExchange.schematics.init();
);
, "cicuitlab");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "135"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f439672%2flow-voltage-shutdown-with-regulator-using-microcontroller%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
A supervisory/comparator or circuit is required if you want to do LDO enable control. One other option are LDO's with undervoltage lockouts which essentially have a comparator built in. Like the one in this question.
LDO with low-voltage cutoff?
Your right, you can't use a microcontroler to do undervoltage control, because it needs voltage to run. You need an external circuit. Another option is to use a pmosfet to do the control, which doesn't require a comparator.
$endgroup$
$begingroup$
Interestingly, I can't find an LDO that has an undervoltage lockout threshold at about 3V, which is a desired threshold to prevent overdischarge of a lithium ion/polymer battery.
$endgroup$
– donut
3 hours ago
$begingroup$
Look for LDO's with a UVLO pin, this one hase a settable range: mouser.com/new/Analog-Devices/adi-adp7104-regulators
$endgroup$
– laptop2d
2 hours ago
add a comment |
$begingroup$
A supervisory/comparator or circuit is required if you want to do LDO enable control. One other option are LDO's with undervoltage lockouts which essentially have a comparator built in. Like the one in this question.
LDO with low-voltage cutoff?
Your right, you can't use a microcontroler to do undervoltage control, because it needs voltage to run. You need an external circuit. Another option is to use a pmosfet to do the control, which doesn't require a comparator.
$endgroup$
$begingroup$
Interestingly, I can't find an LDO that has an undervoltage lockout threshold at about 3V, which is a desired threshold to prevent overdischarge of a lithium ion/polymer battery.
$endgroup$
– donut
3 hours ago
$begingroup$
Look for LDO's with a UVLO pin, this one hase a settable range: mouser.com/new/Analog-Devices/adi-adp7104-regulators
$endgroup$
– laptop2d
2 hours ago
add a comment |
$begingroup$
A supervisory/comparator or circuit is required if you want to do LDO enable control. One other option are LDO's with undervoltage lockouts which essentially have a comparator built in. Like the one in this question.
LDO with low-voltage cutoff?
Your right, you can't use a microcontroler to do undervoltage control, because it needs voltage to run. You need an external circuit. Another option is to use a pmosfet to do the control, which doesn't require a comparator.
$endgroup$
A supervisory/comparator or circuit is required if you want to do LDO enable control. One other option are LDO's with undervoltage lockouts which essentially have a comparator built in. Like the one in this question.
LDO with low-voltage cutoff?
Your right, you can't use a microcontroler to do undervoltage control, because it needs voltage to run. You need an external circuit. Another option is to use a pmosfet to do the control, which doesn't require a comparator.
answered 4 hours ago
laptop2dlaptop2d
30.5k123791
30.5k123791
$begingroup$
Interestingly, I can't find an LDO that has an undervoltage lockout threshold at about 3V, which is a desired threshold to prevent overdischarge of a lithium ion/polymer battery.
$endgroup$
– donut
3 hours ago
$begingroup$
Look for LDO's with a UVLO pin, this one hase a settable range: mouser.com/new/Analog-Devices/adi-adp7104-regulators
$endgroup$
– laptop2d
2 hours ago
add a comment |
$begingroup$
Interestingly, I can't find an LDO that has an undervoltage lockout threshold at about 3V, which is a desired threshold to prevent overdischarge of a lithium ion/polymer battery.
$endgroup$
– donut
3 hours ago
$begingroup$
Look for LDO's with a UVLO pin, this one hase a settable range: mouser.com/new/Analog-Devices/adi-adp7104-regulators
$endgroup$
– laptop2d
2 hours ago
$begingroup$
Interestingly, I can't find an LDO that has an undervoltage lockout threshold at about 3V, which is a desired threshold to prevent overdischarge of a lithium ion/polymer battery.
$endgroup$
– donut
3 hours ago
$begingroup$
Interestingly, I can't find an LDO that has an undervoltage lockout threshold at about 3V, which is a desired threshold to prevent overdischarge of a lithium ion/polymer battery.
$endgroup$
– donut
3 hours ago
$begingroup$
Look for LDO's with a UVLO pin, this one hase a settable range: mouser.com/new/Analog-Devices/adi-adp7104-regulators
$endgroup$
– laptop2d
2 hours ago
$begingroup$
Look for LDO's with a UVLO pin, this one hase a settable range: mouser.com/new/Analog-Devices/adi-adp7104-regulators
$endgroup$
– laptop2d
2 hours ago
add a comment |
$begingroup$
I like this problem and it's kinda common to see something like it where an enable has to be constructed from a set of input signals.
Obviously your microcontroller can establish a PWR_Run signal from it's GPIO output, but it can't do that all the time. You should decide under what other conditions you want your LDO to turn on and stay on, and then build an or gate out of diodes and resistors.
My first thought would be to sense the rising edge of the input to the LDO as it's connected to VIN using a capacitor and an RC filter to let it turn on for a moment as the switch is connected and setting up the GPIO pin. As VIN charges the LDO input it will also charge EN starting everything up. Then before the resistor pulls the value of EN down to below the turnon threshold the microcontroller can assert GPIO keeping it high until the switch is turned off.
simulate this circuit – Schematic created using CircuitLab
$endgroup$
$begingroup$
Depending on the microprocessor GPIO circuitry, the regulator may never turn on because P1 might be at high impedance at power off.
$endgroup$
– laptop2d
4 hours ago
add a comment |
$begingroup$
I like this problem and it's kinda common to see something like it where an enable has to be constructed from a set of input signals.
Obviously your microcontroller can establish a PWR_Run signal from it's GPIO output, but it can't do that all the time. You should decide under what other conditions you want your LDO to turn on and stay on, and then build an or gate out of diodes and resistors.
My first thought would be to sense the rising edge of the input to the LDO as it's connected to VIN using a capacitor and an RC filter to let it turn on for a moment as the switch is connected and setting up the GPIO pin. As VIN charges the LDO input it will also charge EN starting everything up. Then before the resistor pulls the value of EN down to below the turnon threshold the microcontroller can assert GPIO keeping it high until the switch is turned off.
simulate this circuit – Schematic created using CircuitLab
$endgroup$
$begingroup$
Depending on the microprocessor GPIO circuitry, the regulator may never turn on because P1 might be at high impedance at power off.
$endgroup$
– laptop2d
4 hours ago
add a comment |
$begingroup$
I like this problem and it's kinda common to see something like it where an enable has to be constructed from a set of input signals.
Obviously your microcontroller can establish a PWR_Run signal from it's GPIO output, but it can't do that all the time. You should decide under what other conditions you want your LDO to turn on and stay on, and then build an or gate out of diodes and resistors.
My first thought would be to sense the rising edge of the input to the LDO as it's connected to VIN using a capacitor and an RC filter to let it turn on for a moment as the switch is connected and setting up the GPIO pin. As VIN charges the LDO input it will also charge EN starting everything up. Then before the resistor pulls the value of EN down to below the turnon threshold the microcontroller can assert GPIO keeping it high until the switch is turned off.
simulate this circuit – Schematic created using CircuitLab
$endgroup$
I like this problem and it's kinda common to see something like it where an enable has to be constructed from a set of input signals.
Obviously your microcontroller can establish a PWR_Run signal from it's GPIO output, but it can't do that all the time. You should decide under what other conditions you want your LDO to turn on and stay on, and then build an or gate out of diodes and resistors.
My first thought would be to sense the rising edge of the input to the LDO as it's connected to VIN using a capacitor and an RC filter to let it turn on for a moment as the switch is connected and setting up the GPIO pin. As VIN charges the LDO input it will also charge EN starting everything up. Then before the resistor pulls the value of EN down to below the turnon threshold the microcontroller can assert GPIO keeping it high until the switch is turned off.
simulate this circuit – Schematic created using CircuitLab
edited 4 hours ago
answered 4 hours ago
Andrew MacraeAndrew Macrae
802114
802114
$begingroup$
Depending on the microprocessor GPIO circuitry, the regulator may never turn on because P1 might be at high impedance at power off.
$endgroup$
– laptop2d
4 hours ago
add a comment |
$begingroup$
Depending on the microprocessor GPIO circuitry, the regulator may never turn on because P1 might be at high impedance at power off.
$endgroup$
– laptop2d
4 hours ago
$begingroup$
Depending on the microprocessor GPIO circuitry, the regulator may never turn on because P1 might be at high impedance at power off.
$endgroup$
– laptop2d
4 hours ago
$begingroup$
Depending on the microprocessor GPIO circuitry, the regulator may never turn on because P1 might be at high impedance at power off.
$endgroup$
– laptop2d
4 hours ago
add a comment |
Thanks for contributing an answer to Electrical Engineering Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f439672%2flow-voltage-shutdown-with-regulator-using-microcontroller%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
First, ADC_IN is unlikely to be capable of taking a voltage higher than your VDD, if you're lucky a protection diode will end up powering your VDD net, if you're unlucky it will ruin your microcontroller. I'd advise you to use a voltage divider to monitor 1/2 battery voltage or some fraction of the battery voltage that's less than VDD.
$endgroup$
– Andrew Macrae
5 hours ago
$begingroup$
Would be a LDO with undervoltage lockout be an option for you?
$endgroup$
– Christian B.
4 hours ago
1
$begingroup$
@Andrew yes good point...@Christian I don't see any LDO that has an undervoltage lockout at the voltage I want (about 3V)...it's surprising to me that there's no regulator that shuts down around 3V to prevent overdischarge of lithium ion/polymer batteries.
$endgroup$
– donut
4 hours ago