Project Overview and Analysis

flux

You can connect the sublayout to the MCC board by feeding the 3.3V supply from the MCC into your sublayout's 3V3 power net. This means:
  1. Power Connection:
    • Use (or add) a terminal or net portal labeled 3V3 on your sublayout that is connected to the 3.3V rail.
    • Wire the MCC board’s 3.3V output to this terminal so that the module and its supporting circuitry receive power from the external 3.3V supply.
  2. Common Ground:
    • Ensure that the ground (GND) from the MCC board is also tied to your sublayout's ground (using the proper c2e41937-4268-256c-7ae9-cb8cfb60aed3 component) so that both circuits share the same reference.
This approach lets you power the sublayout solely from the MCC board while maintaining the required connections for proper operation.
Would you like me to suggest schematic changes to add or adjust the net portal/terminal connecting the 3.3V supply?
maxjenkinsonn

maxjenkinsonn

can I run this layout without connecting the 5v terminal

flux

Yes, you can run the layout without connecting the 5V terminal if your design only requires the 3.3V supply. Here are a few points to consider:
  • Unused Terminal:
    If no components in your sublayout are actively using the 5V rail, leaving the 5V terminal unconnected is acceptable. However, make sure that none of the parts require a 5V input for proper operation.
  • DRC Considerations:
    Leaving an expected net unconnected might trigger design rule check warnings. You can either ignore these if they're non-critical or update the schematic to mark the 5V terminal as unused or "No Connect" so that DRC rules do not flag it.
  • Power Integrity:
    Ensure that any parts previously intended to be powered by 5V either operate correctly at 3.3V (if that’s within their acceptable range) or have alternate power configurations (e.g., via internal regulators).
Would you like to update the schematic to mark the 5V terminal as not used or to suppress its connection in DRC?
Mark as No Connect
Suppress DRC Warning
Update Terminal Status
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can you verify that u2 r3 resistor value will output no more than 30ma charging ...
ril3y

ril3y

@copilot can you verify that u2 r3 resistor value will output no more than 30ma charging current to the battery?
2y

copilot

To calculate the charging current for the MCP73831-2ACI/MC (U2), we use the following formula from the MCP73831 datasheet:
I_{SET} = 1000V / R_{PROG}
Where:
  • I_{SET} is the charging current
  • R_{PROG} is the value of the programming resistor, which is R3 in this case
Given that R3 has a resistance of 33kΩ, we substitute it into the formula:
I_{SET} = 1000V / 33kΩ = 30.3mA
So, the charging current provided to the battery when using a 33kΩ resistor for R3 is approximately 30.3mA, which is just slightly above 30mA. It's relatively close but if you need to strictly limit the current to no more than 30mA, you might want to consider using a slightly higher resistance value. For exact 30mA, the resistor should be 33.3kΩ.
Please note that this is an approximate value and actual results may vary due to other factors such as the tolerance of the resistor and the power supply voltage.
2y
ril3y

ril3y

what would a 32k value give me./
2y

copilot

If we use a 32kΩ resistor for R3, we substitute it into the formula:
I_{SET} = 1000V / R_{PROG}
I_{SET} = 1000V / 32kΩ = 31.25mA
So, the charging current provided to the battery when using a 32kΩ resistor for R3 is approximately 31.25mA.
2y
ril3y

ril3y

can you suggest a value that will be below 30ma and is a standard value?
2y

copilot

Sure, to achieve a charging current below 30mA with a standard resistor value, we need to increase the resistance. The closest standard 1% resistor value above 33.3kΩ is 33.6kΩ.
Let's calculate the charging current for this value:
I_{SET} = 1000V / 33.6kΩ = 29.76mA
So, using a 33.6kΩ resistor for R3 will result in a charging current of approximately 29.76mA, which is below 30mA.
Please note that this is an approximate value and actual results may vary due to other factors such as the tolerance of the resistor and the power supply voltage.
2y
ril3y

ril3y

give me a different common value
2y

copilot

Sure, another common standard resistor value that is higher than 33.3kΩ is 34kΩ.
Using this value for R3, we can calculate the charging current as follows:
I_{SET} = 1000V / R_{PROG}
Substituting R_{PROG} with 34kΩ gives:
I_{SET} = 1000V / 34kΩ = 29.41mA
So, using a 34kΩ resistor for R3 would result in a charging current of approximately 29.41mA, which is below 30mA.
Again, please note that this is an approximate value and actual results may vary due to other factors such as the tolerance of the resistor and the power supply voltage.
2y
3
I have 3v3 available to charge this battery. Can i use 3v3 to charge this batter...
ril3y

ril3y

@copilot I have 3v3 available to charge this battery. Can i use 3v3 to charge this battery on u2?
2y

copilot

Yes, you can use a 3.3V supply to charge the battery using the MCP73831-2ACI/MC (U2) battery charger IC.
According to the MCP73831-2ACI/MC datasheet:
  • The input voltage range (VDD) is from 3.75V to 6.0V, but it can operate down to 2.0V after start-up.
  • The IC features a constant current/constant voltage linear charger for single cell Li-Ion and Li-Polymer batteries.
However, there are a few things to note:
  • The lower voltage may result in a slower charge rate. The charge current is set with an external resistor from PROG to Ground. You may need to adjust this resistor value to ensure the charge current is appropriate for your battery and input voltage.
  • You need to make sure your 3.3V supply can provide enough current for the charging process. Check the battery specifications and the MCP73831-2ACI/MC datasheet to determine the required current.
Remember to always refer to the datasheet and battery specifications when designing battery charging circuits.
2y
4
RPROG
Line 1
I_{SET} = 1000V / 34kΩ = 29.41mA
Line 2
BAT max charge current 30ma
RESET
PPS
BT1
CHG
Part Type
LED
HOT_START
C2
Capacitance
1.0uF
R2
Resistance
1.5kΩ
D1
Manufacturer Part Number
LMBR0530T1G

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Learn to Add a Component

GPS01-TD-powered-sublayout

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GPS01-TD module is a quad-mode GPS module that supports BDS/GPS/GLONASS/Galileo/QZSS/ SBAS and fully supports BeiDou B3, which can provide users with high quality, strong anti-jamming and low-power positioning and navigation solutions.

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