Comchip Technology (典琦科技)

CC/SBU

In USB Type-C designs, ESD protection components for the CC and SBU pins are often selected with voltage ratings equivalent to that of the VBUS line.

Information

ESD Protection Guidelines for USB Type-C CC and SBU Pins

1. Low Capacitance Is Essential

CC pins carry configuration and cable orientation signals (often <1 Mbps), but may also support BMC signaling for PD negotiation—avoid excessive capacitance that could distort timing.

SBU pins are used for analog audio or debug UART—require ultra-low capacitance (typically <1.5 pF) to preserve signal fidelity.

2. Bidirectional or Unidirectional Protection

CC pins often benefit from unidirectional TVS diodes, especially when tied to pull-up resistors or MCU GPIOs.

SBU pins should use bidirectional ESD protection due to their analog nature and potential differential signaling.

3. IEC 61000-4-2 Compliance

Select components rated for ±8kV contact / ±15kV air discharge to meet USB Type-C robustness standards.

4. Compact, Low-Profile Packaging

Recommended: DFN1006, SOD-923, or CSP0603 for space-constrained designs near the connector.

5. Avoid Over-Clamping

Ensure clamping voltage is above the operating level but below the damage threshold of connected ICs.

For CC (typically 5V logic), clamp <12V; for SBU (analog), clamp <15V.

ESD protection to prevent VBUS shorting to CC and SBU and causing interface failure.

Since the typical operating voltage for the CC pin is around 5V and for the SBU pin approximately 3.3V, accidental contact with a 20V DC power source can lead to damage of downstream ICs and failure of the interface due to ESD overstress. Therefore, in interface protection design, it is essential not only to meet ESD and EOS requirements, but also to ensure that an accidental VBUS short to CC or SBU does not result in system failure.

Traditional protection components are often selected based on voltage ratings above 20V. However, these devices typically have clamping voltages far exceeding the operating levels of CC and SBU, which can inadvertently cause breakdown of downstream components during transient events.

To address this challenge, Comchip has developed protection solutions that combine ultra-low capacitance with clamping voltages closely matched to the CC and SBU operating levels, while also providing robust protection against accidental DC power contact.

Switching Diode

Schottky Diodes

ESD

TVS

Rectifiers

Transistor

MOSFET

Zener

Bridge Rectifiers

PIN Diode

CC/SBU

Information

ESD Protection Guidelines for USB Type-C CC and SBU Pins

ESD protection to prevent VBUS shorting to CC and SBU and causing interface failure.

CC/SBU

Information

ESD Protection Guidelines for USB Type-C CC and SBU Pins

ESD protection to prevent VBUS shorting to CC and SBU and causing interface failure.

Related Products

Privacy Policy