USBULC6-2M6 : Ultra-low capacitance ESD protection

The need for ultra-low capacitance

The high-speed USB 2.0 standard requires that the capacitance of the signal lines of the transceiver chip, as isolated components, have a capacitance to ground of 10 pF or less with D+ and D- matching within 1.0 pF In addition, several portable applications multiplex audio speaker outputs with USB 2.0 or UART with USB 2.0 on the same connector. The low capacitance switch used to multiplex the two signals has around 5 pF of parasitic capacitance. As a consequence, the capacitance budget for the ESD protection is around 1 pF.  As a matter of fact, in order to ease the implementation of the USB 2.0 ESD protection, STMicroelectronics has introduced an ultra-low capacitance ESD protection (0.65 pF at 240 MHz) featuring a flow-through layout in order to optimize signal integrity.


Targeted applications

	USB 2.0 ports including high-speed USB ports up to 480 Mbit/s as well as full- and low-speed USB ports
	Ethernet port: 10/100/1000 Mbit/s
	Video line protection
	Portable electronics