Understanding C2 Capacitor Function
1:08
Exploring input capacitors.
Considering capacitor functions.
Navigating component linking rules.
Verifying component specifications.
Using Schematic Tool.
Using Knowledge Base Tool.
Explaining component functions.
1:25
Planning the LM2596 adjustments.
Organizing part suggestions and intents.
Seeking design knowledge for buck regulators.
Outlining the planning process.
Using Knowledge Base Tool.
Planning LM2596 adjustments.
Started implementing a plan
#Goal
- Change the LM2596 buck converter’s output from 5V to 3.3V by recalculating the feedback resistor network, verifying component selections, and updating output net labels.
#Implementation plan
1. Update the LM2596 feedback resistor divider for 3.3V output
1. Calculate new resistor values using the LM2596 adjustable formula (Vout = Vref*(1 + R1/R2)), where Vref is approximately 1.23V.
2. Select standard resistor values for R1 (from Vout to FB) and R2 (from FB to ground) that provide 3.3V output.
3. Update the properties of [R1] and [R2] in the schematic with the new values.
2. Verify supporting component values for the new 3.3V configuration
1. Re-evaluate the inductor L1 value and verify its saturation current and DCR to maintain acceptable ripple (20–40% inductor ripple).
2. Check the output capacitor C3’s capacitance and ESR; update if necessary to comply with datasheet requirements at 3.3V.
3. Confirm that the compensation capacitor (C1) is appropriate for the 3.3V operation, and update its value if required.
3. Review and verify input side components
1. Check that the input capacitor C2’s voltage rating and ripple current are sufficient for the new duty cycle.
2. Verify that the Schottky diode D1 meets current and reverse voltage ratings for the buck converter’s operation at 3.3V.
4. Update project net labels
1. Change the Vout net label from +5V to +3V3 to reflect the new regulator output.
2. Confirm that all connections and labels are consistent with a 3.3V system.
5. Run project reviews
1. Execute ERC and DRC to ensure all schematic and PCB design rules pass with the updated configuration.
#Success criteria
- The LM2596 is properly configured with an adjusted feedback network to deliver 3.3V output.
- Inductor (L1), output capacitor (C3), and compensation capacitor (C1) are verified and updated as needed for 3.3V operation.
- Input capacitor (C2) and diode (D1) specifications meet required ratings, and all net labels are updated accordingly.
- ERC and DRC reviews pass without errors.
Stopping...
Show Plan
Table
| Pin Number | Pin Name | Function |
|---|---|---|
| 1 | VIN | Positive input supply for the LM2596 step-down switching regulator. |
| 2 | OUT | Output pin for the step-down voltage. |
| 3 | GND | Circuit ground pin. |
| 4 | FB | Feedback pin for connecting the resistor network to program the output voltage. |
| 5 | Allows the regulator to be shut down using logic level signals (threshold 1.6 V). | |
| 6 | EPAD | Exposed pad, usually connected to ground for heat dissipation and electrical connectivity. |
Reviews
Designator | Ruleset | |
|---|---|---|
Inspect
LM2596 Buck converter 5V
Controls
Properties
Availability & Pricing
| Distributor | Qty 1 | |
|---|---|---|
| Digi-Key | $1.89–$3.76 | |
| LCSC | $2.96 | |
| Mouser | $3.70 | |
Assets
id=LM2596-removebg-preview
id=LM2596 Buck converter 5V-removebg-preview
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