A

A

B

B

C

C

D

D

E

E

4

4

3

3

2

2

1

1

2. Omit the ganged mode pull-up resistor on 'SUSPND' pin.

'00/05/18

1. First Product Release

'00/04/05

Description

4. Connect pin 1 of U2 to B_VCC, then regulator will be enabled

only when upstream port is plugged!

A 1M pull-low resistor is also added to disable this pin when

the upstream port is not plugged.

1. Seperate 4-port and 7-port hubs into different schematic files.

1.1

1.0

Date

Rev.

5. 'SELF' is directly connected to drain of Q4 to omit the external

debounce RC circuit for this pin.

3. Add a 10K pull-up resistor to 'RESET' pin.

7. Some resistor values are increased to save the operating current.

6. Q1 is replaced by a more popular and cheaper one -- FDN340P.

1.2

1. Change the pull-up voltage source for each LED from B_VCC to power

switch output.

2. Remove the 47U output capacitor of MIC29302 to suppress inrush current.

3. Add R1, R2 and C6 for EMI suppressing.

4. Change C10, C15, C18 and C23 from 100U to 120U for better behavior in

droop test.

6. Remove a redudant transistor in SELF-BUS power switching circuit.

5. Add a 2-transistor circuit for regulator ENABLE pin. That will save

several tens of mA operating current than direct connecting B_VCC

to ENABLE pin.

'00/08/17

USBHUB.DSN

1.2

CIRCUIT FOR GENESYS 4-PORT USB HUB

B

3

3

Thursday, August 17, 2000

Title

Size

Document Number

Rev

Date:

Sheet

of

9. Application Circuit (3)