Philips ISP1122 ユーザーズマニュアル

9397 750 07002

© Philips Electronics N.V. 2000. All rights reserved.

[1]

Symbol names with an overscore (e.g. NAME) indicate active LOW signals.

[2]

The voltage at pin V

reg(3.3)

 is gated by the RESET pin. This allows fully self-powered operation by

connecting RESET to V

BUS

 (+5 V USB supply). If V

BUS

 is lost upstream port D+ will not be driven.

[3]

See

[4]

To disable a downstream port connect both D

+

and D

−

to V

CC

via a 1 M

Ω

resistor; unused ports must

be disabled in reverse order starting from port 5.

[5]

Analog detection circuit can be switched off using an external EEPROM, see

; in this case,

the pin functions as a logic input (TTL level).

[6]

Downstream ports 1 and 2 cannot be disabled.

DP1

27

AI/O

downstream port 1 D

+

DM0

28

AI/O

upstream port D

−

 connection (analog)

DP0

29

AI/O

upstream port D

+

 connection (analog)

DM2

30

AI/O

downstream port 2 D

−

 connection (analog)

DP2

31

AI/O

downstream port 2 D

+

 connection (analog)

PSW1/GL1

32

O

modes 4 to 6: power switch control output for downstream
port 1 (open-drain, 6 mA)

modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 1 (open-drain, 6 mA); to connect an LED
use a 330

Ω

 series resistor

…continued