Schematic Design Review Checklist

flux

1:52

Consult.

Analyzing the schematic.

Running design review.

Reviewing the bill of materials.

Looking for "Typical Application circuit and external components (capacitors, resistors) requirements" in fusb302b-d.pdf

Looking for "VDD supply decoupling capacitor recommendation" in fusb302b-d.pdf

Looking for "I2C SCL SDA pull-up resistor requirement" in fusb302b-d.pdf

Looking for "INT_N pin description and required pull-up or connection guidance" in fusb302b-d.pdf

Looking for "VCONN pins description and whether they may be tied to VDD" in fusb302b-d.pdf

Schematic-level issues observed (actionable) 1) Floating / unconnected interface nets (logic + connectivity)
These nets are only connected to the IC pin and do not connect to the corresponding net portals, so they are effectively not routed anywhere else:
  • I2C clock net: U1 SCL appears only on Net (U1 - SCL) (only U1:SCL). The SCL portal is present but not actually connected to that net.
  • I2C data net: U1 SDA appears only on Net (SDA - P1) (only U1:SDA). The SDA portal is present but not connected.
  • Interrupt net: U1 INT_N appears only on Net (U1 - INT_N) (only U1:INT_N). The FUSB302_INT portal is present but not connected.
Correction
2) USB2 D+/D- host-side not connected (signal path incomplete)
Your D+/D- path currently terminates at the ESD/series-resistor node and never reaches the named net portals:
  • D+ path: Net (USB type-C - DP1) includes connector DP pins and R3 P1, but R3 P2 only connects to D1 IO4 on Net (D1 - IO4). The USB_D portals exist but are not connected to either side of R3.
  • D- path: Net (USB type-C - DN2) includes connector DN pins and R1 P1, but R1 P2 only connects to D1 IO3 on Net (R1 - P2). The USB_D- portals exist but are not connected.
Correction
  • Connect the host-side net portals to the series-resistor/ESD node:
3) Missing required pull-ups (datasheet-backed)
Per the U1 datasheet guidance:
  • I2C pull-ups missing: There are no resistors pulling up SCL/SDA to a supply rail. Datasheet “Recommended Component Values” calls for I2C pull-up resistors (typ 4.7 kΩ) to a pull-up voltage between 1.71 V and VDD.
  • INT_N pull-up missing: INT_N is an open-drain output and needs an external pull-up. Datasheet reference schematic shows an INT_N pull-up (min 1.0 kΩ, typ 4.7 kΩ).
Correction
  • Add two pull-ups (SCL, SDA) and one pull-up (INT_N) to the appropriate pull-up rail used by your host MCU (within the datasheet’s allowed pull-up range).
4) Power/decoupling: incomplete VDD decoupling (datasheet-backed)
On the U1 VDD net (Net (U1 - VDD)), you have only:
  • C2 = 0.1 µF to GND.
The datasheet explicitly calls out two VDD decouplers:
  • CVDD1 = 0.1 µF (typ)
  • CVDD2 = 1.0 µF (typ)
Correction
  • Add a 1.0 µF capacitor from VDD to GND in addition to C2, and place it as the second VDD decoupler for U1.
5) VCONN supply is tied into VDD net (likely incorrect per datasheet intent)
In your schematic, U1 VCONN pins (12, 13) are connected to Net (U1 - VDD) (same net as VDD pins 3, 4).
The datasheet description indicates VCONN is a regulated input intended to be switched onto the CC pin as VCONN, and the reference schematic shows VCONN as a separate supply net (with its own decoupling distinct from VDD).
Correction
  • Split U1 VCONN onto its own net/supply (instead of shorting it to VDD), and decouple it per the reference schematic approach.
6) Power net labeling consistency: unused +5V portals
Multiple 5V power net portals exist, but there is no +5V net in the netlist section, meaning they are not actually connected to anything.
Correction
  • Either wire your intended 5 V rail to these 5V portals, or remove/rename them so the schematic has only the rails that are actually used (right now, only Net (VBUS - P1) and Net (U1 - VDD) are real power nets in use).
Items that look electrically connected (no issue observed from connectivity alone)
  • CC pins are consistently tied across connector + controller + ESD + shunt caps:
  • Shield “soft tie” network exists: USB_SHIELD is connected to GND via R2 (10 kΩ) and C5 (0.01 µF).
If you want, I can turn the above into a concrete edit checklist (exactly which pins to wire to which portals, and which new resistors/capacitors to add), but I’ll keep it schematic-level as requested.
Check ERC/DRC items
Fix I2C/INT nets
Connect USB D+/D-
Add missing pull-ups
Add 1uF decoupler
47 days
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    USB Type-C FUSB302 Template-removebg-preview.png

    USB Type-C FUSB302 Template-removebg-preview.png

    USB Type-C FUSB302 Template-removebg-previewThumbnail

    USB Type-C FUSB302 Template

    USB Type-C FUSB302 Template thumbnail
    Programmable USB Type‐C Controller with Power Delivery(PD) support. Include ESD Protection Diodes. #project-template #USB #typec #powerdelivery #template

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