Schematic for Big Emerald R2-D2: 12 V Automotive UPS-Style...

12V DC UPS Stabilizer Design

flux

2:59

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Schematic

Screenshot 2026-01-09 082957.png

Planning schematic queries.

Analyzing connectivity issues.

Using Schematic Tool.

Using Knowledge Base Tool.

Looking for "Recommended Vdd connection and decoupling capacitor value" in 4357fd.pdf

Looking for "Typical application schematic decoupling and connections of IN, OUT, GATE, Vdd, GND" in 4357fd.pdf

Looking for "Absolute maximum ratings for Vdd, IN, OUT" in 4357fd.pdf

Looking for "Pin description Vdd and OUT pins" in 4357fd.pdf

Looking for "Typical application schematic" in 4357fd.pdf

Looking for "Pin descriptions Vdd OUT GATE" in 4357fd.pdf

Looking for "Bypass capacitor recommendation for Vdd to GND" in 4357fd.pdf

Looking for "Typical application schematic" in 4357fd.pdf

Looking for "Pin descriptions VDD OUT GATE" in 4357fd.pdf

Looking for "Bypass or decoupling capacitor recommendation for VDD" in 4357fd.pdf

Fetching schematic details.

Looks good overall. I checked your actual nets and here’s a focused review with any fixes.

What’s correct

Input chain and TVS
- J1 → F1 → R1 → U1 IN and Q1 S are on U1.
- D1 is across the input (cathode on J1 P1 via Net 4, anode to GND). Placement is correct.
Ideal‑diode stage
- U1:OUT and Vdd are on the downstream node with Q1:D (NET_OUTPUT). Good.
- U1:GATE to Q1:G only (Net 5). Correct.
Supercap bank and balance
- SC1 → SC2 → SC3 → SC4 → SC5 → SC6 series is correct; SC6 P2 returns to GND.
- Rbal1–Rbal6 each span their cell’s P1–P2 nets. Good.
Output filter
- Q1 D → L1 P1; L1 P2 → J2 P1 with C1 220 µF and C2 100 nF to GND (Net 6). Correct.

Required fixes and recommendations

TVS part number: You specified 1.5KE18CA (bidirectional). The current device on D1 is 1.5KE18A (unidirectional). Replace it with 1.5KE18CA to match the requirement.
LTC4357 VDD decoupling (from the datasheet)
- The datasheet states: “For applications up to 30 V, bypass the VDD pin with 39 µF; above 30 V use at least 100 µF. If VDD is powered from the output side, one capacitor serves to guard against VDD collapse and also protect OUT from voltage spikes. If OUT is diode-clamped or VDD is powered from input, use a separate 100 Ω, 100 nF filter (increase to 1 µF above 10 A).”
- Action: Add a local VDD bypass for U1 per the above. In your case, with VDD tied to OUT, place a bypass from VDD/OUT to GND near U1.
Supercap properties: Your SC1–SC6 placeholders still say 256 F. Update to 25 F, 3 V and use a polarized footprint/symbol for the final MPN (Eaton TV1625-3R0256-R), since the real parts are polarized.

Want me to:

swap D1 to 1.5KE18CA,
add the LTC4357 VDD bypass per datasheet,
and update SC1–SC6 to 25 F/3 V?

Say “apply those fixes” and I’ll make the edits.

19 days

Plan completed.

Show Plan

SC3

Capacitance

256 F

Capacitance

100 nF

Rbal6

Resistance

1kΩ

Rbal4

Resistance

1kΩ

Capacitance

220 µF

SC1

Capacitance

256 F

Rbal5

Resistance

1kΩ

Rbal3

Resistance

1kΩ

SC2

Capacitance

256 F

Rbal1

Resistance

1kΩ

SC5

Capacitance

256 F

Inductance

47 µH

SC4

Capacitance

256 F

SC6

Capacitance

256 F

C1 P1 - GND GND

Rbal2

Resistance

1kΩ

Resistance

5 Ω

Reviews

Electrical Rule Checks

Missing Footprints

Reports parts that have no footprint.

Design Rule Checks

Overlapping Copper

Reports copper elements that are shorting.

Invalid Layer

Reports nodes that are assigned to a layer that doesn't exist in the layout stackup.

Component Overrides

Reports components that have been modified using the "!important" flag.

Airwires • 4

	Designators	Net
	Trace 3da9:Trace 3da9, Trace 57a3:Trace 57a3	Net 3
	Trace d58e:Trace d58e, C1:P1	Net 6
	Q1:D, Trace 41dd:Trace 41dd	NET_OUTPUT
	Trace c24a:Trace c24a, SC1:P1	NET_OUTPUT

Deprecated Rules

Reports nodes that are using rules that are not supported anymore.

Layers with Multiple Fills

Reports layers that have multiple copper fills of different nets. Make sure the Connected Layers rule value of nets with fills is valid.

Floating Copper • 3

	Name
	Trace feb9
	Trace c43b
	Trace 437c

Protected Intrusions

Reports intrusions from objects of other nets into polygons or fills that have the Protected layout rule applied.

Manufacturing

Manufacturer Part Number • 15

	Designator	MPN
	C1	None
	C2	None
	L1	None
	Rbal1	None
	Rbal2	None
	Rbal3	None
	Rbal4	None
	Rbal5	None
	Rbal6	None
	SC1	None
	SC2	None
	SC3	None
	SC4	None
	SC5	None
	SC6	None

Parts Available

Beta

Checks that all parts have a part number and are available from distributors.

System Checks

Auto-Layout

Beta

Reports issues with Auto-Layout if Flux cannot route something or must ignore a configuration.

Passive Components

Resistor Power Rating

Beta

Checks that the power traveling across a given resistor is under its rating with 50% headroom.

Learn more

Pull Up/Pull Down Presence

Beta

Checks that IC pins that require pull up or pull down resistors have them.

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Capacitor Voltage Rating

Beta

Checks that capacitors have appropriate voltage ratings to prevent overheating and ensure reliable circuit operation.

Ground
A common return path for electric current. Commonly known as ground.
jharwinbarrozo
20.5M
Net Portal
Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
jharwinbarrozo
43.0M
Power Net Portal
Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
jharwinbarrozo
11.4M
Generic Resistor
A generic fixed resistor for rapid developing circuit topology. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0Ω 10Ω 100Ω 1.0kΩ 10kΩ 100kΩ 1.0MΩ 1.1Ω 11Ω 110Ω 1.1kΩ 11kΩ 110kΩ 1.1MΩ 1.2Ω 12Ω 120Ω 1.2kΩ 12kΩ 120kΩ 1.2MΩ 1.3Ω 13Ω 130Ω 1.3kΩ 13kΩ 130kΩ 1.3MΩ 1.5Ω 15Ω 150Ω 1.5kΩ 15kΩ 150kΩ 1.5MΩ 1.6Ω 16Ω 160Ω 1.6kΩ 16kΩ 160kΩ 1.6MΩ 1.8Ω 18Ω 180Ω 1.8KΩ 18kΩ 180kΩ 1.8MΩ 2.0Ω 20Ω 200Ω 2.0kΩ 20kΩ 200kΩ 2.0MΩ 2.2Ω 22Ω 220Ω 2.2kΩ 22kΩ 220kΩ 2.2MΩ 2.4Ω 24Ω 240Ω 2.4kΩ 24kΩ 240kΩ 2.4MΩ 2.7Ω 27Ω 270Ω 2.7kΩ 27kΩ 270kΩ 2.7MΩ 3.0Ω 30Ω 300Ω 3.0KΩ 30KΩ 300KΩ 3.0MΩ 3.3Ω 33Ω 330Ω 3.3kΩ 33kΩ 330kΩ 3.3MΩ 3.6Ω 36Ω 360Ω 3.6kΩ 36kΩ 360kΩ 3.6MΩ 3.9Ω 39Ω 390Ω 3.9kΩ 39kΩ 390kΩ 3.9MΩ 4.3Ω 43Ω 430Ω 4.3kΩ 43KΩ 430KΩ 4.3MΩ 4.7Ω 47Ω 470Ω 4.7kΩ 47kΩ 470kΩ 4.7MΩ 5.1Ω 51Ω 510Ω 5.1kΩ 51kΩ 510kΩ 5.1MΩ 5.6Ω 56Ω 560Ω 5.6kΩ 56kΩ 560kΩ 5.6MΩ 6.2Ω 62Ω 620Ω 6.2kΩ 62KΩ 620KΩ 6.2MΩ 6.8Ω 68Ω 680Ω 6.8kΩ 68kΩ 680kΩ 6.8MΩ 7.5Ω 75Ω 750Ω 7.5kΩ 75kΩ 750kΩ 7.5MΩ 8.2Ω 82Ω 820Ω 8.2kΩ 82kΩ 820kΩ 8.2MΩ 9.1Ω 91Ω 910Ω 9.1kΩ 91kΩ 910kΩ 9.1MΩ #generics #CommonPartsLibrary
jharwinbarrozo
1.5M
Generic Capacitor
A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF 10pF 100pF 1000pF 0.01uF 0.1uF 1.0uF 10uF 100uF 1000uF 10,000uF 1.1pF 11pF 110pF 1100pF 1.2pF 12pF 120pF 1200pF 1.3pF 13pF 130pF 1300pF 1.5pF 15pF 150pF 1500pF 0.015uF 0.15uF 1.5uF 15uF 150uF 1500uF 1.6pF 16pF 160pF 1600pF 1.8pF 18pF 180pF 1800pF 2.0pF 20pF 200pF 2000pF 2.2pF 22pF 20pF 2200pF 0.022uF 0.22uF 2.2uF 22uF 220uF 2200uF 2.4pF 24pF 240pF 2400pF 2.7pF 27pF 270pF 2700pF 3.0pF 30pF 300pF 3000pF 3.3pF 33pF 330pF 3300pF 0.033uF 0.33uF 3.3uF 33uF 330uF 3300uF 3.6pF 36pF 360pF 3600pF 3.9pF 39pF 390pF 3900pF 4.3pF 43pF 430pF 4300pF 4.7pF 47pF 470pF 4700pF 0.047uF 0.47uF 4.7uF 47uF 470uF 4700uF 5.1pF 51pF 510pF 5100pF 5.6pF 56pF 560pF 5600pF 6.2pF 62pF 620pF 6200pF 6.8pF 68pF 680pF 6800pF 0.068uF 0.68uF 6.8uF 68uF 680uF 6800uF 7.5pF 75pF 750pF 7500pF 8.2pF 82pF 820pF 8200pF 9.1pF 91pF 910pF 9100pF #generics #CommonPartsLibrary
jharwinbarrozo
1.5M
Generic Inductor
A generic fixed inductor for rapid developing circuit topology. *You can now change the footprint and 3D model at the top level anytime you want. This is the power of #generics
jharwinbarrozo
15.1k
Terminal
An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
natarius
RMCF0805JT47K0
47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film #forLedBlink
jharwinbarrozo
1.2M
875105359001
10uF Capacitor Aluminum Polymer 20% 16V SMD 5x5.3mm #forLedBlink #commonpartslibrary #capacitor #aluminumpolymer #radialcan
jharwinbarrozo
1.2M
CTL1206FYW1T
Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric) #forLedBlink
jharwinbarrozo
1.1M

Inspect

Big Emerald R2-D2

Controls

Properties

layer_count

copper_weight

supercap_keepout

pour_width_L1

Role Details

ground_plane_L2

System Architecture

Availability & Pricing

Distributor		Qty 1
	Arrow	$3.35–$4.83
	Digi-Key	$5.62
	LCSC	$7.06–$7.16
	Mouser	$6.18
	TME	$0.33
	Verical	$11.06–$13.29

Assets

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