Protection device goes both ways on USB

Edited by the Electronicstalk editorial team Feb 22, 2005

The EClamp3343C protection device has a novel design that allows it to work with both upstream and downstream USB 2.0 (full speed) and on-the-go (OTG) ports in portable electronics and peripherals.

The EClamp3343C is a protection device with a unique design that allows it to work with both upstream and downstream USB 2.0 (full speed) and on-the-go (OTG) ports in portable electronics and peripherals.

The EClamp3343C is the latest member of Semtech's EMIClamp family of protection devices.

The product protects USB ports from electrostatic discharge (ESD) and also filters electromagnetic interference (EMI).

It is the only USB protection device on the market with terminating 1.5kohm pull-up and 15kohm pull-down resistors that allow it to identify the type of port it is supporting.

The configurable nature of the product reduces the need to qualify and inventory multiple devices, speeding time to market and lowering costs.

Semtech's EClamp3343C also integrates a 33ohm series termination resistor for impedance matching, and, unlike other devices, this solution allows for a separate connection from the 3.3V supply to the pull-up resistor for full compliance to the USB specification.

The device's high level of integration is further enhanced by its small size - a 1.96 x 1.33 x 0.65mm, 11-bump flip chip - which is ideally suited for applications with limited board space.

"The USB interface is proliferating and spreading to more innovative consumer devices, increasing the likelihood of damaging electrical charges and emphasizing the need for reliable protection", said Tom Dugan, Semtech Director of Protection Products.

"This device rises to these challenges with an ultra-small footprint and flexible USB support that is sure to meet the needs of the design engineer, the procurement staff, and eventually the end user".

ESD protection is provided by TVS diodes on D+, D-, Vbus and the ID pin for OTG designs.

ESD surges in excess of +/-8kV contact and +/-15kV air discharge are suppressed as mandated by the IEC61000-4-2, Level 4, a protection standard required for consumer electronics.

Because USB is a plug-and-play standard, ESD and EMI are particular threats to USB ports due to the increased vulnerability on the data, voltage and ID pins to fatal charges from a user plugging in a charged cable.

The EClamp3343C comes standard with Semtech's exclusive nonconductive back coating technology that offers increased mechanical durability, improves marking, and is compliant with UL94V0 flammability requirements.

It is available in a lead-free (Pb-free) version.

The EClamp3343C is available immediately in production quantities and is priced at $0.40 each in 10,000-piece lots.