Very-low-capacitance (3.5 pF max) ESD protection array dedicated to two high-speed data lines such as USB 2.0, in a SOT-23-6 package. Each I/O pair steers ESD strikes through internal diodes to GND or the VBUS rail, clamping the transient while adding little capacitance so signal integrity holds at USB speeds. IEC 61000-4-2 level 4 rated. Place it right at the connector across D+/D- with VBUS to the 5 V rail. The default USB port protector.

Pinout

Pin	Name	Type	Function
1	I/O1	passive	Protected data line 1 (e.g. USB D+ or D-). Bidirectional signal pin clamped by steering diodes to GND and VBUS; also tied to pin 6 (same net). Typical capacitance to GND 2.5 pF, max 3.5 pF at 1 MHz.
2	GND	power_in	Ground reference. Cathode return for the lower steering diodes and anode of the internal clamping Zener; must be connected to system ground with the shortest possible trace to minimize parasitic inductance during an ESD event.
3	I/O2	passive	Protected data line 2 (e.g. USB D- or D+). Bidirectional signal pin clamped by steering diodes to GND and VBUS; also tied to pin 4 (same net). Typical capacitance to GND 2.5 pF, max 3.5 pF at 1 MHz.
4	I/O2	passive	Second bond pad for the I/O2 data line; internally shorted to pin 3. Route the data line to either pin 3 or 4 (or both) as convenient for the PCB layout.
5	VBUS	power_in	Positive supply rail reference for the ESD clamp (typ +5 V for USB). Provides the upper rail for the steering diodes and is clamped to GND through the internal Zener; VBR = 6 V min at IF = 1 mA. Bypass to GND with a 100 nF capacitor placed close to the device for optimal ESD performance.
6	I/O1	passive	Second bond pad for the I/O1 data line; internally shorted to pin 1. Route the data line to either pin 1 or 6 (or both) as convenient for the PCB layout.

Key specifications

Parameter	Value
Type	USB ESD protection array (2 lines)
Line capacitance	3.5 pF max (very low)
ESD rating	IEC 61000-4-2 level 4 (device level)
Leakage	150 nA max
Protected lines	2 (I/O1, I/O2)
Rail	VBUS clamp reference
Package	SOT-23-6
Body (L×W×H)	2.9 × 1.6 × 1.1 mm

Ordering variants

Same part, different packaging or reel option.

USBLC6-2SC6 (SOT-23-6, tape & reel)

CAD (KiCad official)

Symbol: Power_Protection:USBLC6-2SC6
Footprint: Package_TO_SOT_SMD:SOT-23-6
3D model: SOT-23-6 (KiCad packages3D)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: STMicroelectronics datasheet (11 pp, sha256 e593275721905c80, retrieved 2026-08-17, tier: cse)
Extractor: ds2sf (Claude) — every pin and dimension is cited to a datasheet page; refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF