217
www.littelfuse.com
5
TVS DIODE ARRAYS
TVS Diode Arrays
Upstream USB Port Terminator with ESD Suppression & EMI Filtering
The Littelfuse SPUSB1 Series is a multifunctional USB port protection
network designed to provide ESD protection, EMI/RFI filtering and line
termination for a single USB 1.1 port. The SPUSB1 can replace a mini-
mum of ten typically larger “discrete” devices resulting in inventory and
placement cost savings.
The SPUSB1 Series combines Transient Voltage Suppression (TVS)
avalanche diodes, EMI/RFI filtering components (R1 and C1), and
a1.5kΩ termination resistor (R2). The filtering components are included
to satisfy recommendations in the USB 1.1 specification, and the 1.5kΩ
resistor (R2) is included as a pull-up resistor to VBUS.
The SPUSB1 Series can be used for termination and protection
of“upstream” USB devices such as PDAs, digital cameras, scanners and
hubs which are often at risk from transient voltage surges and
electromagnetic interference from both internal and external sources.
To support a wide range of circuit conditions, Littelfuse offers three
resistance values for the series resistor (R1). The series resistance plus
the USB driver output resistance must be close to the USB cable’s char-
acteristic impedance of 45Ω (90Ω balanced) to minimize transmission
line reflections.
Circuit Diagram
Features
• One upstream USB port terminator, EMI filter and transient
overvoltage protector in a single surface-mount package
• Compact SC70 package saves board space and lowers
manufacturing costs compared to discrete solutions
• ESD protection to 30kV contact discharge per MIL-STD- 883D,
method 3015
• ESD protection to 15kV contact discharge per IEC 61000-4-2
international standard
Applications
• Desktop/Laptop PCs
• USB peripherals (printers, scanners, zip drives)
• PDAs / wireless handsets
• Digital cameras
• MP3 Players
• Cable Modems
Ordering Information