FSA4485 datasheet(13/31 Pages) ONSEMI

13 / 31 page

FSA4485

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Accessory attach detection DET will clear automatically

when the Type−C device or audio accessory is detached.

Figure 5. Detect Pin Function

Gate Drive

The FSA4485 includes two gate drive outputs GD1 and

GD2 to allow a low resistance external switch to be used for

AGND. The gate drives are enabled from the I2C register

GATE_DRIVE_EN and will follow automatic orientation

detection. When enabled, if SBU1 = AGND then GD1 =

High, If SBU2 = AGND then GD2 = High.

The gate to source voltage (Vgs) will be held at V_GATE

to ensure low on resistance. The maximum gate drive

current can be selected from the I2C register

GATE_DRIVE_CURR to control switch turn on time.

GATE DRIVE CURRENT

GATE_DRIVE_CURR

00b

1 mA

01b

1.5 mA

10b

2.0 mA (default)

11b

3.0 mA

EN and Factory Mode

The enable input (EN) is a 3 state input which sets the USB

and SBU data switch initial conditions during device power

up. It has a weak internal pull down which will set the default

condition to High−Z if no input level is present. For

applications using the SBU signals for data the EN input can

be floated or connected to a GPIO in High−Z state at power

up. For typical conditions EN can be tied to GND. EN is tied

to GND using a 10 k

W resistor if also using the EN input to

disable the device. It is not recommended that the EN =

High−Z condition be used if the system uses SBU for the

DisplayPort Aux channel.

Figure 6. EN Input Truth Table

FSA4485 Datasheet(PDF) 13 Page - ON Semiconductor