TUSB2040A

4-PORT HUB FOR THE UNIVERSAL SERIAL BUS

WITH OPTIONAL SERIAL EEPROM INTERFACE

SLLS288B – FEBRUARY 1998 – REVISED MARCH 1998

4

POST OFFICE BOX 655303

Terminal Functions

TERMINAL

I/O

DESCRIPTION

NAME

NPT

I/O

DESCRIPTION

BUSPWR/SCL

9

10

I/O

Power source input/EEPROM serial clock. When EXTMEM is low, BUSPWR/SCL is an active

low input that indicates whether the ports and the hub derive power from the bus or the local

supply. When EXTMEM is high, BUSPWR/SCL acts as a tri-state serial clock output to the

EEPROM with a 100

µA internal pulldown. This standard TTL input must not change dynamically

during operation.

DM0

5

2

I/O

Root port USB differential data minus. DM0 paired with DP0 constitutes the upstream USB port.

DM1 – DM4

8, 12,

15, 17

7, 14,

19, 24

I/O

USB differential data minus. DM1 – DM4 paired with DP1 – DP4 support up to four downstream

USB ports.

DP0

4

1

I/O

Root port USB differential data plus. DP0 paired with DM0 constitutes the upstream USB port.

DP1 – DP4

7, 11,

14, 16

6, 13,

18, 23

I/O

USB differential data plus. DP1 – DP4 paired with DM1 – DM4 support up to four downstream

USB ports.

GANGED/SDA

10

11

I/O

Power switching and overcurrent detection mode/EEPROM serial data I/O. When EXTMEM is

low, GANGED/SDA selects between gang or per port switching for the overcurrent detection of

the downstream ports. When EXTMEM is high, GANGED/SDA acts as a tri-state serial data I/O

to and from the EEPROM with a 100

µA internal pull-down. This standard TTL input must not

change dynamically during operation.

GND

6, 24

3, 36

Ground. GND terminals must be tied to ground for proper operation.

EXTMEM

21

32

I

EEPROM read enable. When EXTMEM is low, it disables the serial EEPROM interface of the

device. Pins 9 and 10 are configured as BUSPWR and GANGED, respectively. When EXTMEM

is high, it enables the serial EEPROM interface and pins 9 and 10 are configured as SCL and

SDA, respectively.

OVRCUR1 –

OVRCUR4

3, 1,

26, 19

48, 46,

38, 27

I

Overcurrent indicators. OVRCUR1 – OVRCUR4 are active low, standard TTL inputs. One

overcurrent indicator is available for each of the four downstream ports. In GANGED mode, one

implementation is to tie these inputs together. Alternatively, one OVRCUR input pin may be used

with the remaining OVRCUR pins tied to VCC.

PWRON1 –

PWRON4

2, 28,

25, 20

47, 44,

37, 29

O

Power-on/-off control signals. PWRON1 – PWRON4 are active low, open-drain outputs. One

power-on/-off control switch is used for each of the four downstream ports. In GANGED mode,

all outputs are switched together.

RESET

18

25

I

Reset. RESET is an active low TTL input with hysteresis and must be asserted at power up. When

RESET is asserted, it initializes all logic.

SUSPND

20

O

Suspend status. SUSPND is an active high output that is available for external logic power down

operations. During the SUSPEND mode, SUSPND is high. SUSPND is low for normal operation.

VCC

13, 27

15, 41

3.3-V supply voltage

XTAL1

23

35

I

Crystal 1. XTAL1 is a 48-MHz crystal input with 50% duty cycle. Operation at 48-MHz is four times

the USB full-speed bit rate of 12 Mbps.

XTAL2

22

34

O

Crystal 2. XTAL2 is a 48-MHz crystal output. Operation at 48-MHz is four times the USB full-speed

bit rate of 12 Mbps. This terminal is left open when using an oscillator.

– 0.5 V to 3.8 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

±20 mA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

±20 mA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

–65

°C to 150°C

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and

functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not

implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTE 1: All voltage levels are with respect to GND.