RT6224D-based step down circuit yields 0V - why?





.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ margin-bottom:0;
}







3












$begingroup$


We received a set of prototype boards. They have a DC power supply input feeding into a step-down converter, which is built around an RT6224D. It is supposed to deliver 5.0V. The circuit is almost exactly straight from the datasheet, just that the designer chose a 3.3 uH inductivity.



Here is what we have:
enter image description here



This is the Typical Application Circuit from the datasheet:
enter image description here



The problem is, I get exactly 0V at the output. And I can not figure out why. Even on a quick breadboard reproduction of the same circuit, I still get 0 output. I have this feeling there must be something very obvious.



Do you have any idea what is going on here? I greatly appreciate your help!



Edit to answer SamGibson's questions:



(a) PCB layout:
enter image description here



(b) The populated PCB, sorry I don't have an unpopulated board:
enter image description here



(c) Someone else did the design and the layout, I am just trying to make it work. The boards came from a domestic manufacturer. I talked with the designer about the issue, he said U6 it must be a faulty chip. On all 5 boards. So I replaced it with a new one, same result.



(d) I don't know where the board manufacturer got the components initially, my replacement was from Digikey.



(e) I can't find any usable signal to scope, VIN and EN are at 12V, all other pins show a flat lines at 0V.



(f) The inductor is an ASPI-4030S-3R3M-T.



Thanks!



Edit 2:



This is my "hotfix" based on the feedback by Randy Nuss and Spehro Pefhany. The originial RT6224D did not work any more, but with a new chip and the 100k resistor, I get the desired 12V:



enter image description here










share|improve this question









New contributor




ChrisH is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$












  • $begingroup$
    Welcome :-) Please edit your question to add: (a) the PCB layout from your EDA software; (b) a photo of this part of the PCB - preferably from an unpopulated PCB and a populated one, but add whatever variations you have; (c) explain the history of the design - did you make a working prototype first (if so, add a photo of that) or did you go from schematic straight to these PCBs? (d) where did you source the regulator ICs from e.g. known distributor, or AliExpress/Ebay etc.? (e) have you used an oscilloscope to see if there is any attempt for the IC to start? (f) link to inductor datasheet?
    $endgroup$
    – SamGibson
    Apr 13 at 16:08










  • $begingroup$
    Thanks for the update. I didn't look further at the start, until that update was available, and the lack of evidence you have been given by the original designer for point (c) i.e the history, is especially revealing - there is no history that the design has ever worked! They seem to have gone straight from schematic to PCB, meaning we have to consider possible design problems, not just layout or manufacturing problems. Looking at it from that perspective, Randy has likely identified the problem. Good luck with a replacement chip, a resistor and a scalpel (X-Acto knife) to rework the PCB.
    $endgroup$
    – SamGibson
    Apr 13 at 17:54












  • $begingroup$
    That is true, I am not aware of any prototypes between the schematic and the pcb.
    $endgroup$
    – ChrisH
    Apr 13 at 18:19










  • $begingroup$
    Hi ChrisH, your edit looks like an answer which (slightly expanded) would belong to the answer section?
    $endgroup$
    – bummi
    10 hours ago


















3












$begingroup$


We received a set of prototype boards. They have a DC power supply input feeding into a step-down converter, which is built around an RT6224D. It is supposed to deliver 5.0V. The circuit is almost exactly straight from the datasheet, just that the designer chose a 3.3 uH inductivity.



Here is what we have:
enter image description here



This is the Typical Application Circuit from the datasheet:
enter image description here



The problem is, I get exactly 0V at the output. And I can not figure out why. Even on a quick breadboard reproduction of the same circuit, I still get 0 output. I have this feeling there must be something very obvious.



Do you have any idea what is going on here? I greatly appreciate your help!



Edit to answer SamGibson's questions:



(a) PCB layout:
enter image description here



(b) The populated PCB, sorry I don't have an unpopulated board:
enter image description here



(c) Someone else did the design and the layout, I am just trying to make it work. The boards came from a domestic manufacturer. I talked with the designer about the issue, he said U6 it must be a faulty chip. On all 5 boards. So I replaced it with a new one, same result.



(d) I don't know where the board manufacturer got the components initially, my replacement was from Digikey.



(e) I can't find any usable signal to scope, VIN and EN are at 12V, all other pins show a flat lines at 0V.



(f) The inductor is an ASPI-4030S-3R3M-T.



Thanks!



Edit 2:



This is my "hotfix" based on the feedback by Randy Nuss and Spehro Pefhany. The originial RT6224D did not work any more, but with a new chip and the 100k resistor, I get the desired 12V:



enter image description here










share|improve this question









New contributor




ChrisH is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$












  • $begingroup$
    Welcome :-) Please edit your question to add: (a) the PCB layout from your EDA software; (b) a photo of this part of the PCB - preferably from an unpopulated PCB and a populated one, but add whatever variations you have; (c) explain the history of the design - did you make a working prototype first (if so, add a photo of that) or did you go from schematic straight to these PCBs? (d) where did you source the regulator ICs from e.g. known distributor, or AliExpress/Ebay etc.? (e) have you used an oscilloscope to see if there is any attempt for the IC to start? (f) link to inductor datasheet?
    $endgroup$
    – SamGibson
    Apr 13 at 16:08










  • $begingroup$
    Thanks for the update. I didn't look further at the start, until that update was available, and the lack of evidence you have been given by the original designer for point (c) i.e the history, is especially revealing - there is no history that the design has ever worked! They seem to have gone straight from schematic to PCB, meaning we have to consider possible design problems, not just layout or manufacturing problems. Looking at it from that perspective, Randy has likely identified the problem. Good luck with a replacement chip, a resistor and a scalpel (X-Acto knife) to rework the PCB.
    $endgroup$
    – SamGibson
    Apr 13 at 17:54












  • $begingroup$
    That is true, I am not aware of any prototypes between the schematic and the pcb.
    $endgroup$
    – ChrisH
    Apr 13 at 18:19










  • $begingroup$
    Hi ChrisH, your edit looks like an answer which (slightly expanded) would belong to the answer section?
    $endgroup$
    – bummi
    10 hours ago














3












3








3





$begingroup$


We received a set of prototype boards. They have a DC power supply input feeding into a step-down converter, which is built around an RT6224D. It is supposed to deliver 5.0V. The circuit is almost exactly straight from the datasheet, just that the designer chose a 3.3 uH inductivity.



Here is what we have:
enter image description here



This is the Typical Application Circuit from the datasheet:
enter image description here



The problem is, I get exactly 0V at the output. And I can not figure out why. Even on a quick breadboard reproduction of the same circuit, I still get 0 output. I have this feeling there must be something very obvious.



Do you have any idea what is going on here? I greatly appreciate your help!



Edit to answer SamGibson's questions:



(a) PCB layout:
enter image description here



(b) The populated PCB, sorry I don't have an unpopulated board:
enter image description here



(c) Someone else did the design and the layout, I am just trying to make it work. The boards came from a domestic manufacturer. I talked with the designer about the issue, he said U6 it must be a faulty chip. On all 5 boards. So I replaced it with a new one, same result.



(d) I don't know where the board manufacturer got the components initially, my replacement was from Digikey.



(e) I can't find any usable signal to scope, VIN and EN are at 12V, all other pins show a flat lines at 0V.



(f) The inductor is an ASPI-4030S-3R3M-T.



Thanks!



Edit 2:



This is my "hotfix" based on the feedback by Randy Nuss and Spehro Pefhany. The originial RT6224D did not work any more, but with a new chip and the 100k resistor, I get the desired 12V:



enter image description here










share|improve this question









New contributor




ChrisH is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




We received a set of prototype boards. They have a DC power supply input feeding into a step-down converter, which is built around an RT6224D. It is supposed to deliver 5.0V. The circuit is almost exactly straight from the datasheet, just that the designer chose a 3.3 uH inductivity.



Here is what we have:
enter image description here



This is the Typical Application Circuit from the datasheet:
enter image description here



The problem is, I get exactly 0V at the output. And I can not figure out why. Even on a quick breadboard reproduction of the same circuit, I still get 0 output. I have this feeling there must be something very obvious.



Do you have any idea what is going on here? I greatly appreciate your help!



Edit to answer SamGibson's questions:



(a) PCB layout:
enter image description here



(b) The populated PCB, sorry I don't have an unpopulated board:
enter image description here



(c) Someone else did the design and the layout, I am just trying to make it work. The boards came from a domestic manufacturer. I talked with the designer about the issue, he said U6 it must be a faulty chip. On all 5 boards. So I replaced it with a new one, same result.



(d) I don't know where the board manufacturer got the components initially, my replacement was from Digikey.



(e) I can't find any usable signal to scope, VIN and EN are at 12V, all other pins show a flat lines at 0V.



(f) The inductor is an ASPI-4030S-3R3M-T.



Thanks!



Edit 2:



This is my "hotfix" based on the feedback by Randy Nuss and Spehro Pefhany. The originial RT6224D did not work any more, but with a new chip and the 100k resistor, I get the desired 12V:



enter image description here







power-supply voltage-regulator switch-mode-power-supply






share|improve this question









New contributor




ChrisH is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









New contributor




ChrisH is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question








edited 10 hours ago







ChrisH













New contributor




ChrisH is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked Apr 13 at 15:48









ChrisHChrisH

185




185




New contributor




ChrisH is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





ChrisH is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






ChrisH is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.












  • $begingroup$
    Welcome :-) Please edit your question to add: (a) the PCB layout from your EDA software; (b) a photo of this part of the PCB - preferably from an unpopulated PCB and a populated one, but add whatever variations you have; (c) explain the history of the design - did you make a working prototype first (if so, add a photo of that) or did you go from schematic straight to these PCBs? (d) where did you source the regulator ICs from e.g. known distributor, or AliExpress/Ebay etc.? (e) have you used an oscilloscope to see if there is any attempt for the IC to start? (f) link to inductor datasheet?
    $endgroup$
    – SamGibson
    Apr 13 at 16:08










  • $begingroup$
    Thanks for the update. I didn't look further at the start, until that update was available, and the lack of evidence you have been given by the original designer for point (c) i.e the history, is especially revealing - there is no history that the design has ever worked! They seem to have gone straight from schematic to PCB, meaning we have to consider possible design problems, not just layout or manufacturing problems. Looking at it from that perspective, Randy has likely identified the problem. Good luck with a replacement chip, a resistor and a scalpel (X-Acto knife) to rework the PCB.
    $endgroup$
    – SamGibson
    Apr 13 at 17:54












  • $begingroup$
    That is true, I am not aware of any prototypes between the schematic and the pcb.
    $endgroup$
    – ChrisH
    Apr 13 at 18:19










  • $begingroup$
    Hi ChrisH, your edit looks like an answer which (slightly expanded) would belong to the answer section?
    $endgroup$
    – bummi
    10 hours ago


















  • $begingroup$
    Welcome :-) Please edit your question to add: (a) the PCB layout from your EDA software; (b) a photo of this part of the PCB - preferably from an unpopulated PCB and a populated one, but add whatever variations you have; (c) explain the history of the design - did you make a working prototype first (if so, add a photo of that) or did you go from schematic straight to these PCBs? (d) where did you source the regulator ICs from e.g. known distributor, or AliExpress/Ebay etc.? (e) have you used an oscilloscope to see if there is any attempt for the IC to start? (f) link to inductor datasheet?
    $endgroup$
    – SamGibson
    Apr 13 at 16:08










  • $begingroup$
    Thanks for the update. I didn't look further at the start, until that update was available, and the lack of evidence you have been given by the original designer for point (c) i.e the history, is especially revealing - there is no history that the design has ever worked! They seem to have gone straight from schematic to PCB, meaning we have to consider possible design problems, not just layout or manufacturing problems. Looking at it from that perspective, Randy has likely identified the problem. Good luck with a replacement chip, a resistor and a scalpel (X-Acto knife) to rework the PCB.
    $endgroup$
    – SamGibson
    Apr 13 at 17:54












  • $begingroup$
    That is true, I am not aware of any prototypes between the schematic and the pcb.
    $endgroup$
    – ChrisH
    Apr 13 at 18:19










  • $begingroup$
    Hi ChrisH, your edit looks like an answer which (slightly expanded) would belong to the answer section?
    $endgroup$
    – bummi
    10 hours ago
















$begingroup$
Welcome :-) Please edit your question to add: (a) the PCB layout from your EDA software; (b) a photo of this part of the PCB - preferably from an unpopulated PCB and a populated one, but add whatever variations you have; (c) explain the history of the design - did you make a working prototype first (if so, add a photo of that) or did you go from schematic straight to these PCBs? (d) where did you source the regulator ICs from e.g. known distributor, or AliExpress/Ebay etc.? (e) have you used an oscilloscope to see if there is any attempt for the IC to start? (f) link to inductor datasheet?
$endgroup$
– SamGibson
Apr 13 at 16:08




$begingroup$
Welcome :-) Please edit your question to add: (a) the PCB layout from your EDA software; (b) a photo of this part of the PCB - preferably from an unpopulated PCB and a populated one, but add whatever variations you have; (c) explain the history of the design - did you make a working prototype first (if so, add a photo of that) or did you go from schematic straight to these PCBs? (d) where did you source the regulator ICs from e.g. known distributor, or AliExpress/Ebay etc.? (e) have you used an oscilloscope to see if there is any attempt for the IC to start? (f) link to inductor datasheet?
$endgroup$
– SamGibson
Apr 13 at 16:08












$begingroup$
Thanks for the update. I didn't look further at the start, until that update was available, and the lack of evidence you have been given by the original designer for point (c) i.e the history, is especially revealing - there is no history that the design has ever worked! They seem to have gone straight from schematic to PCB, meaning we have to consider possible design problems, not just layout or manufacturing problems. Looking at it from that perspective, Randy has likely identified the problem. Good luck with a replacement chip, a resistor and a scalpel (X-Acto knife) to rework the PCB.
$endgroup$
– SamGibson
Apr 13 at 17:54






$begingroup$
Thanks for the update. I didn't look further at the start, until that update was available, and the lack of evidence you have been given by the original designer for point (c) i.e the history, is especially revealing - there is no history that the design has ever worked! They seem to have gone straight from schematic to PCB, meaning we have to consider possible design problems, not just layout or manufacturing problems. Looking at it from that perspective, Randy has likely identified the problem. Good luck with a replacement chip, a resistor and a scalpel (X-Acto knife) to rework the PCB.
$endgroup$
– SamGibson
Apr 13 at 17:54














$begingroup$
That is true, I am not aware of any prototypes between the schematic and the pcb.
$endgroup$
– ChrisH
Apr 13 at 18:19




$begingroup$
That is true, I am not aware of any prototypes between the schematic and the pcb.
$endgroup$
– ChrisH
Apr 13 at 18:19












$begingroup$
Hi ChrisH, your edit looks like an answer which (slightly expanded) would belong to the answer section?
$endgroup$
– bummi
10 hours ago




$begingroup$
Hi ChrisH, your edit looks like an answer which (slightly expanded) would belong to the answer section?
$endgroup$
– bummi
10 hours ago










1 Answer
1






active

oldest

votes


















8












$begingroup$

I'm fairly certain you're blowing up the chip by applying 12V to the EN pin. According to the data sheet the ABS MAX rating on that pin is 6V. Typically one would use a voltage divider to attenuate the input voltage to a value that would yield around 3V on the EN pin with 12V applied.






share|improve this answer









$endgroup$









  • 4




    $begingroup$
    Looks right. I think OP can simply connect it to Vin through 100K. "For automatic start-up the EN pin can be connected to VIN, through a 100kΩ resistor. "
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 16:58






  • 1




    $begingroup$
    Good catch Spehro! I missed that. Adding only one resistor will make the rework much easier.
    $endgroup$
    – Randy Nuss
    Apr 13 at 17:20






  • 2




    $begingroup$
    Thanks, Randy and Sphero, that is a great point. I had tried this with the very first board I got, lifted pin 4 up, air-wired a 100k to 12V, did not help. But then again, that chip might have been dead from our first attempt to start it up. Will cut some traces, put the 100k on the board, and report back.
    $endgroup$
    – ChrisH
    Apr 13 at 18:18






  • 3




    $begingroup$
    The chip will be dead. Try bending the lead up before soldering the new one down and bridge 4 to 5 on top of the chip with a 100K 0402 resistor for your "field enhancement".
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 19:16






  • 1




    $begingroup$
    Yes, that did the trick! Thank you so much for your help :) I will add a "revision" photo to the original post.
    $endgroup$
    – ChrisH
    10 hours ago












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
});


}
});






ChrisH is a new contributor. Be nice, and check out our Code of Conduct.










draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f432373%2frt6224d-based-step-down-circuit-yields-0v-why%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









8












$begingroup$

I'm fairly certain you're blowing up the chip by applying 12V to the EN pin. According to the data sheet the ABS MAX rating on that pin is 6V. Typically one would use a voltage divider to attenuate the input voltage to a value that would yield around 3V on the EN pin with 12V applied.






share|improve this answer









$endgroup$









  • 4




    $begingroup$
    Looks right. I think OP can simply connect it to Vin through 100K. "For automatic start-up the EN pin can be connected to VIN, through a 100kΩ resistor. "
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 16:58






  • 1




    $begingroup$
    Good catch Spehro! I missed that. Adding only one resistor will make the rework much easier.
    $endgroup$
    – Randy Nuss
    Apr 13 at 17:20






  • 2




    $begingroup$
    Thanks, Randy and Sphero, that is a great point. I had tried this with the very first board I got, lifted pin 4 up, air-wired a 100k to 12V, did not help. But then again, that chip might have been dead from our first attempt to start it up. Will cut some traces, put the 100k on the board, and report back.
    $endgroup$
    – ChrisH
    Apr 13 at 18:18






  • 3




    $begingroup$
    The chip will be dead. Try bending the lead up before soldering the new one down and bridge 4 to 5 on top of the chip with a 100K 0402 resistor for your "field enhancement".
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 19:16






  • 1




    $begingroup$
    Yes, that did the trick! Thank you so much for your help :) I will add a "revision" photo to the original post.
    $endgroup$
    – ChrisH
    10 hours ago
















8












$begingroup$

I'm fairly certain you're blowing up the chip by applying 12V to the EN pin. According to the data sheet the ABS MAX rating on that pin is 6V. Typically one would use a voltage divider to attenuate the input voltage to a value that would yield around 3V on the EN pin with 12V applied.






share|improve this answer









$endgroup$









  • 4




    $begingroup$
    Looks right. I think OP can simply connect it to Vin through 100K. "For automatic start-up the EN pin can be connected to VIN, through a 100kΩ resistor. "
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 16:58






  • 1




    $begingroup$
    Good catch Spehro! I missed that. Adding only one resistor will make the rework much easier.
    $endgroup$
    – Randy Nuss
    Apr 13 at 17:20






  • 2




    $begingroup$
    Thanks, Randy and Sphero, that is a great point. I had tried this with the very first board I got, lifted pin 4 up, air-wired a 100k to 12V, did not help. But then again, that chip might have been dead from our first attempt to start it up. Will cut some traces, put the 100k on the board, and report back.
    $endgroup$
    – ChrisH
    Apr 13 at 18:18






  • 3




    $begingroup$
    The chip will be dead. Try bending the lead up before soldering the new one down and bridge 4 to 5 on top of the chip with a 100K 0402 resistor for your "field enhancement".
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 19:16






  • 1




    $begingroup$
    Yes, that did the trick! Thank you so much for your help :) I will add a "revision" photo to the original post.
    $endgroup$
    – ChrisH
    10 hours ago














8












8








8





$begingroup$

I'm fairly certain you're blowing up the chip by applying 12V to the EN pin. According to the data sheet the ABS MAX rating on that pin is 6V. Typically one would use a voltage divider to attenuate the input voltage to a value that would yield around 3V on the EN pin with 12V applied.






share|improve this answer









$endgroup$



I'm fairly certain you're blowing up the chip by applying 12V to the EN pin. According to the data sheet the ABS MAX rating on that pin is 6V. Typically one would use a voltage divider to attenuate the input voltage to a value that would yield around 3V on the EN pin with 12V applied.







share|improve this answer












share|improve this answer



share|improve this answer










answered Apr 13 at 16:45









Randy NussRandy Nuss

33915




33915








  • 4




    $begingroup$
    Looks right. I think OP can simply connect it to Vin through 100K. "For automatic start-up the EN pin can be connected to VIN, through a 100kΩ resistor. "
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 16:58






  • 1




    $begingroup$
    Good catch Spehro! I missed that. Adding only one resistor will make the rework much easier.
    $endgroup$
    – Randy Nuss
    Apr 13 at 17:20






  • 2




    $begingroup$
    Thanks, Randy and Sphero, that is a great point. I had tried this with the very first board I got, lifted pin 4 up, air-wired a 100k to 12V, did not help. But then again, that chip might have been dead from our first attempt to start it up. Will cut some traces, put the 100k on the board, and report back.
    $endgroup$
    – ChrisH
    Apr 13 at 18:18






  • 3




    $begingroup$
    The chip will be dead. Try bending the lead up before soldering the new one down and bridge 4 to 5 on top of the chip with a 100K 0402 resistor for your "field enhancement".
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 19:16






  • 1




    $begingroup$
    Yes, that did the trick! Thank you so much for your help :) I will add a "revision" photo to the original post.
    $endgroup$
    – ChrisH
    10 hours ago














  • 4




    $begingroup$
    Looks right. I think OP can simply connect it to Vin through 100K. "For automatic start-up the EN pin can be connected to VIN, through a 100kΩ resistor. "
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 16:58






  • 1




    $begingroup$
    Good catch Spehro! I missed that. Adding only one resistor will make the rework much easier.
    $endgroup$
    – Randy Nuss
    Apr 13 at 17:20






  • 2




    $begingroup$
    Thanks, Randy and Sphero, that is a great point. I had tried this with the very first board I got, lifted pin 4 up, air-wired a 100k to 12V, did not help. But then again, that chip might have been dead from our first attempt to start it up. Will cut some traces, put the 100k on the board, and report back.
    $endgroup$
    – ChrisH
    Apr 13 at 18:18






  • 3




    $begingroup$
    The chip will be dead. Try bending the lead up before soldering the new one down and bridge 4 to 5 on top of the chip with a 100K 0402 resistor for your "field enhancement".
    $endgroup$
    – Spehro Pefhany
    Apr 13 at 19:16






  • 1




    $begingroup$
    Yes, that did the trick! Thank you so much for your help :) I will add a "revision" photo to the original post.
    $endgroup$
    – ChrisH
    10 hours ago








4




4




$begingroup$
Looks right. I think OP can simply connect it to Vin through 100K. "For automatic start-up the EN pin can be connected to VIN, through a 100kΩ resistor. "
$endgroup$
– Spehro Pefhany
Apr 13 at 16:58




$begingroup$
Looks right. I think OP can simply connect it to Vin through 100K. "For automatic start-up the EN pin can be connected to VIN, through a 100kΩ resistor. "
$endgroup$
– Spehro Pefhany
Apr 13 at 16:58




1




1




$begingroup$
Good catch Spehro! I missed that. Adding only one resistor will make the rework much easier.
$endgroup$
– Randy Nuss
Apr 13 at 17:20




$begingroup$
Good catch Spehro! I missed that. Adding only one resistor will make the rework much easier.
$endgroup$
– Randy Nuss
Apr 13 at 17:20




2




2




$begingroup$
Thanks, Randy and Sphero, that is a great point. I had tried this with the very first board I got, lifted pin 4 up, air-wired a 100k to 12V, did not help. But then again, that chip might have been dead from our first attempt to start it up. Will cut some traces, put the 100k on the board, and report back.
$endgroup$
– ChrisH
Apr 13 at 18:18




$begingroup$
Thanks, Randy and Sphero, that is a great point. I had tried this with the very first board I got, lifted pin 4 up, air-wired a 100k to 12V, did not help. But then again, that chip might have been dead from our first attempt to start it up. Will cut some traces, put the 100k on the board, and report back.
$endgroup$
– ChrisH
Apr 13 at 18:18




3




3




$begingroup$
The chip will be dead. Try bending the lead up before soldering the new one down and bridge 4 to 5 on top of the chip with a 100K 0402 resistor for your "field enhancement".
$endgroup$
– Spehro Pefhany
Apr 13 at 19:16




$begingroup$
The chip will be dead. Try bending the lead up before soldering the new one down and bridge 4 to 5 on top of the chip with a 100K 0402 resistor for your "field enhancement".
$endgroup$
– Spehro Pefhany
Apr 13 at 19:16




1




1




$begingroup$
Yes, that did the trick! Thank you so much for your help :) I will add a "revision" photo to the original post.
$endgroup$
– ChrisH
10 hours ago




$begingroup$
Yes, that did the trick! Thank you so much for your help :) I will add a "revision" photo to the original post.
$endgroup$
– ChrisH
10 hours ago










ChrisH is a new contributor. Be nice, and check out our Code of Conduct.










draft saved

draft discarded


















ChrisH is a new contributor. Be nice, and check out our Code of Conduct.













ChrisH is a new contributor. Be nice, and check out our Code of Conduct.












ChrisH is a new contributor. Be nice, and check out our Code of Conduct.
















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.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f432373%2frt6224d-based-step-down-circuit-yields-0v-why%23new-answer', 'question_page');
}
);

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







Popular posts from this blog

Plaza Victoria

Puebla de Zaragoza

Musa