© 2010 Fairchild Semiconductor Corporation

www.fairchildsemi.com

FSA806 • Rev. 1.0.1

3

Mode Descriptions

The

FSA806

select

pins

control

the

switching

operations, SEL[0] and SEL[1] described in Table 1

Table 1.

Selection Truth Table

SEL[1]

SEL[0]

Switch Action

Description

0

0

OPEN

Open all switch paths (device in low-power mode)

0

1

USB1, UART

Closes USB1 path to D+/D-, default condition

(1)

- DP_CON connected to DP_HOST1

- DM_CON connected to DM_HOST1

1

0

USB2, UART

Closes USB2 path to D+/D-

- DP_CON connected to DP_HOST2

- DM_CON connected to DM_HOST2

1

1

AUDIO

Closes audio path to D+/D- only

- DP_CON connected to R_HOST

- DM_CON connected to L_HOST

Notes:

1.

The SELECT pins are CMOS inputs and should not be left in a floating condition. Some applications require a

UART path be in the CLOSED position on power-up for initial programming of the device under test. If that

condition is desired, the two SELECT pins should be pulled to the correct levels with external resistors that

should exceed 100KΩ to reduce the static power consumption. In other applications, adding weak pull-down

resistors to GND defaults the device to all paths open (low-power mode).

2.

When the audio switch is in the OPEN position, the R and L are terminated to GND with internal termination

resistors to discharge any stray capacitance that could cause audio pop.