STF202–22

http://onsemi.com

5

The Figure 10 describes in a simplified way what the USB

port components are. As shown in this diagram, there are

signals for upstream and downstream ports which must be

provided with Line Termination and EMI Filtering to meet

the requirements of the USB specification revision 1.1. In

addition to the Line termination and EMI Filtering, it is also

needed to protect the USB I/O Lines against ESD

conditions, so TVS devices must be added for these

purposes.

Figure 10.

XTAL1

XTAL2

DPO

DMO

GND

DP1–DP4

DM1–DM4

OC1–OC4

PWR1–PWR4

REGULATOR

POWER

SWITCHING

GND

D–

D+

USB Data Lines

and Power to

Downstream

Ports

To

Upstream

Ports

CLK

CRISTAL

As mentioned before, the ON Semiconductor STF202

device provides “upstream termination”, EMI Filtering and

ESD Protection to IEC6100–4–2 in an integrated solution

placed in a small and single package (TSOP–6, Case 318G).

The typical application for the STF202 device is shown in

the Figure 11.

Figure 11.

D1D+

D1D–

OC

PWR

DOD+

DOD–

REGULATOR

TVS

D+

D–

STF202

654

123

GND

OC

PWR

D2D+

D2D–

TVS

POWER

SWITCH

D+

D–

GND

DOWNSTREAM

TERMINATION

D+

D–

GND

DOWNSTREAM

TERMINATION

USB CONTROLLER