Application InformationUSB Interface Protection RClamp0512TQ is be used to protect D+ and D- lines. For USB 3.0 applications, RClamp3324P is recommended These lines are routed through RClamp0512TQ at pin1 for protecting the 5Gb/s SuperSpeed line pairs. Fig- and pin 2. Pin 3 is connected to the ground plane. ure 1 below shows an example of protecting a USB 3.0 RClamp0512TQ is qualified to AEC-Q100. Additional Type-A interfaces (host side shown). Lines are routed information may be found on the device data sheet. through each device entering at pins 1, 2, 4, and 5 and exiting at pins 10, 9, 7, and 6 respectively (Figure 2). Each Single line devices such as uClamp0571P are recom- trace should run under the device and connect the pins mended for surge and ESD protection of the VBus line. together. Ground connection is made at the center tabs This device features high surge and ESD capability and (pins 3, and 8 ). Traces should be kept the same length may be used on 5V power rails. In power delivery (PD) to avoid impedance mismatch. The differential imped- applications, higher working voltage TVS device may be ance of each pair can be controlled for USB 3.0 (85 Ohms needed. Options exist for ESD and surge protection up +/-15%) while maintaining a minimum trace-to-trace and to 24V. trace-to-pad spacing. Individual PCB design constraints may necessitate different spacing or trace width. Both Device Placement ground pads should be connected for optimal perfor- Placement of the protection component is a critical ele- mance. Ground connection is made using filled via-in- ment for effective ESD suppression. TVS diodes should pad. be placed as close to the connector as possible. This helps reduce transient coupling to nearby traces. Ground connections should be made directly to the ground plane using micro-vias. This reduces parasitic inductance in the ground path and minimizes the clamp- ing voltage seen by the protected device. Figure 1 - USB 3.0 Type-A Protection ExampleFigure 2 - Trace Routing USB 3.0 - Type A Host Connector Line 1 In 1 Line 1 Out to IC RClamp0512TQ SSRX- Line 2 In Line 2 Out to IC GND D+ Via to Ground Ground SSRX+ Landing Pad Device Outline GND Trace Line 3 In Line 3 Out to IC SSTX- D- RClamp3324P Line 4 In Line 4 Out to IC VBus SSTX+ Trace Device Land Pattern Via uClamp0571P RClamp3324P www.semtech.com 5 of 8Final DatasheetRev 6.1SemtechRevision DateOctober 4, 2016
