Schematic Symbol for MCP73871-1AAI/ML - SUBLAYOUT: Lipo battery...

Schematic Design Review

flux

2:07

General

Chat History

Project

Datasheet

Knowledge Base

Using Knowledge Base Tool.

Looking for "reverse current blocking from battery to input or system path" in MCP73871-Data-Sheet-20002090E.pdf

Looking for "power path management system load sharing ideal diode reverse current" in MCP73871-Data-Sheet-20002090E.pdf

Looking for "backflow protection description IN to BAT or SYS to IN" in MCP73871-Data-Sheet-20002090E.pdf

Looking for "USB host back-powering prevention or reverse current to adapter" in MCP73871-Data-Sheet-20002090E.pdf

Looking for "Electrical Characteristics reverse leakage currents between pins IN, BAT, OUT" in MCP73871-Data-Sheet-20002090E.pdf

Looking for "Functional description of OUT pin and system power path" in MCP73871-Data-Sheet-20002090E.pdf

Looking for "Protection features: reverse discharge protection, power source selection" in MCP73871-Data-Sheet-20002090E.pdf

Verifying reverse current protection.

Answering backflow protection.

Clarifying circuit details.

Finalizing the MCP73871 response.

Crafting a concise response.

Short answer: Yes — the charger IC here, IC2 (MCP73871), integrates reverse/backflow protection.

What the datasheet says (verbatim figures)

Reverse‑blocking protection on input: “provides protection from a faulted or shorted input,” preventing the battery from discharging into the input through internal body diodes (Section 6.1.1.4 Reverse‑Blocking Protection).
Reverse discharge limits:
- UVLO: “battery reverse discharge current is less than 2 μA.”
- Electrical characteristics (Output reverse leakage current, IDISCHARGE): 30–40 μA in Shutdown (various conditions); −6 to −13 μA at Charge Complete.
Power‑path with ideal‑diode operation: Low‑loss power‑path management; when input current is insufficient, the ideal‑diode allows the battery to supplement the system load (this is intended behavior, not a backflow fault).

Schematic note

The anodes of STAT1, STAT2, and PG LEDs are tied to the input net (“Net (CIN - P2)”), so the PG/STAT outputs are not pulled above VIN. The datasheet cautions that PG “must not be pulled up higher than VIN” due to an internal diode path back to VIN; your wiring is consistent with that.

5 days

Ready.

Resistance

470 Ω

VBAT

STAT2

Part Type

LED

Resistance

470 Ω

Capacitance

4.7u F

IC2

Manufacturer Name

Microchip Technology

Manufacturer Part Number

MCP73871-1AAI/ML

Resistance

470 Ω

STAT1

Reviews

Electrical Rule Checks

Missing Footprints

Reports parts that have no footprint.

Design Rule Checks

Overlapping Copper • 33

Des	Net	Des	Net
IC2:VSS	GND	IC2:810f3415	None
IC2:VSS	GND	IC2:810f3415	None
IC2:VSS	GND	IC2:810f3415	None
IC2:VSS	GND	IC2:810f3415	None
RPROG2:P1	GND	VBAT:VBAT	Net (IC2 - Vbat_SENSE)
Trace 30b8	GND	IC2:810f3415	None
Trace 42ed	GND	IC2:810f3415	None
Trace 80ea	GND	IC2:810f3415	None
Trace 178b	GND	IC2:810f3415	None
Trace 561e	GND	IC2:810f3415	None
Trace 3432	GND	IC2:810f3415	None
Via	GND	IC2:810f3415	None
5V:5V	Net (IC2 - IN)	IC2:STAT2	Net (R1 - P1)
5V:5V	Net (IC2 - IN)	R3:P1	Net (R3 - P1)
5V:5V	Net (IC2 - IN)	IC2:810f3415	None
5V:5V	Net (IC2 - IN)	IC2:810f3415	None
3V3:3V3	Net (IC2 - OUT)	IC2:VBAT	Net (IC2 - Vbat_SENSE)
3V3:3V3	Net (IC2 - OUT)	IC2:810f3415	None
3V3:3V3	Net (IC2 - OUT)	IC2:810f3415	None
RPROG2:P2	Net (IC2 - PROG2)	VBAT:VBAT	Net (IC2 - Vbat_SENSE)
VBAT:VBAT	Net (IC2 - Vbat_SENSE)	C1:P1	GND
VBAT:VBAT	Net (IC2 - Vbat_SENSE)	IC2:810f3415	None
VBAT:VBAT	Net (IC2 - Vbat_SENSE)	IC2:810f3415	None
R1:P1	Net (R1 - P1)	VBAT:VBAT	Net (IC2 - Vbat_SENSE)
IC2:810f3415	None	Trace 8bf8	GND
IC2:810f3415	None	Trace 8757	GND
IC2:810f3415	None	Trace c50e	GND
IC2:810f3415	None	Trace e597	GND
IC2:810f3415	None	Trace e716	GND
IC2:810f3415	None	Trace feec	GND
IC2:810f3415	None	Via	GND
IC2:810f3415	None	Via	GND
IC2:810f3415	None	Via	GND

Invalid Layer

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

Component Overrides • 19

	Designator	Ruleset
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀VALUE｀＊	Override rule for ＊｀VALUE｀＊
	＊｀VALUE｀＊	Override rule for ＊｀VALUE｀＊
	＊｀VALUE｀＊	Override rule for ＊｀VALUE｀＊
	＊｀VALUE｀＊	Override rule for ＊｀VALUE｀＊
	＊｀VALUE｀＊	Override rule for ＊｀VALUE｀＊
	＊｀VALUE｀＊	Override rule for ＊｀VALUE｀＊
	＊｀VALUE｀＊	Override rule for ＊｀VALUE｀＊
	＊｀VALUE｀＊	Override rule for ＊｀VALUE｀＊
	＊｀VALUE｀＊	Override rule for ＊｀VALUE｀＊

Airwires

Reports missing routed traces between pads in a net.

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

Detect any via, trace or copper fill island that is not connected to any net.

Protected Intrusions

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

Manufacturing

Manufacturer Part Number • 1

	Designator	MPN
	RPROG3	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.

Learn more

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