XR

22404

5/14

REV1A

Pin Functions

QFN-24

Pin Number

SSOP-28

Pin Number

Pin Name

Type Description

Center Pad

1

GND

PWR

Digital ground (in QFN package Center Pad must be connected to digital ground).

3

2

XTALOUT

O

12 MHz crystal feedback output.

4

3

XTALIN

I

12 MHz ± 50 ppm crystal input with load capacitance rating of 16-20 pF.

5

4

DM4

I/O

Downstream port 4 USB D- data.

6

5

DP4

I/O

Downstream port 4 USB D+ data.

7

6

DM3

I/O

Downstream port 3 USB D- data.

8

7

DP3

I/O

Downstream port 3 USB D+ data.

9

8

DM2

I/O

Downstream port 2 USB D- data.

10

9

DP2

I/O

Downstream port 2 USB D+ data.

11

10

DM1

I/O

Downstream port 1 USB D- data.

12

11

DP1

I/O

Downstream port 1 USB D+ data.

-

12

TEST2

-

Leave unconnected for normal operation.

-

13

TEST3

-

Leave unconnected for normal operation.

13

14

REXT

I

External bias resistor. Connect 2.7kΩ 1% resistor from this pin to GND.

14

15

UP_DM

I/O

Upstream port USB D- data.

15

16

UP_DP

I/O

Upstream port USB D+ data.

16

17

EXT_RST#

I

External reset input, active low. Must be asserted for a minimum of 10 µS.

17

18

VBUS_SENSE

I

Active high. Indicates connection to USB host. Connect to VBUS power input from

USB host through series 10kΩ registor. A 100kΩ pull-down registor and 100nF shunt

capacitance are required on this pin.

18

19

BUS_PWR#

I

Bus power indicator, active low. For bus powered mode, connect to ground. For self-

powered mode, connect to logic ‘1’.

19

20

VCC5

PWR

5V power to internal 5V to 3.3V regulator, unused when device is powered by 3.3V.

20

21

VCC33

PWR

3.3V power input, when device is powered by 3.3V. If device is powered by 5V to VCC5

pin, decouple this pin with 4.7 µF.

21

22

LED_CTL/

CHRGEN

I/O

LED hub active indicator or downstream port charge enable, active high. May also be

used in conjunction with port status LEDs. If sampled high during power up reset,

all downstream ports may be used as charging ports. Refer to Table 1.

22

23

LED1/SCL

I/O

used in conjunction with LED_CTL/CHRGEN pin.

23

24

LED2

I/O

Port 2 LED indicator. Max source current 3 mA. May be used in conjunction with DRV pin.

Refer to Figure 3.

24

25

PWR#

O

Power enable for all downstream devices. Asserted when XR22404 device is configured

and OVC# is not asserted. Deasserted (high) if OVC# input is asserted or XR22404 is

not configured.

1

26

OVC#

I

Downstream port global overcurrent indicator, active low.

2

27

TEST#/SDA

I

-

28

TEST4

-

Leave unconnected for normal operation.

NOTE:

Type: I = Input, O = Output, I/O = Input/Output, PWR = Power, OD = Open-Drain.