Philips ISP1521 ユーザーズマニュアル

9397 750 13702

© Koninklijke Philips Electronics N.V. 2004. All rights reserved.

For an overcurrent limit of 500 mA per port, a PMOS with R

DSON

 of approximately

100 m

Ω

 is required. If a PMOS with a lower R

DSON

 is used, analog overcurrent

detection can be adjusted by using a series resistor; see

.

∆

V

PMOS

=

∆

V

trip

=

∆

V

trip(intrinsic)

−

(I

OC(nom)

×

R

td

), where:

∆

V

PMOS

= voltage drop on PMOS

I

OC(nom)

= 0.6

µ

A.

The I

2

C-bus cannot be shared between the EEPROM and the external microcontroller; see

.

(1) The function on port 7, which is a non-removable port, is optional.

004aaa302

ROM

external microcontroller

acting as I

2

C-bus master

USB function

EEPROM

I

2

C-bus

green and

amber LEDs,

port 1

green and

amber LEDs,

port 7(1)

7 USB downstream facing ports

. .

upstream 

facing port

GoodLink

(1) R

td

 is optional.

004aaa260

VREF(5V0)

Rtd(1)

5 V

OCn_N

PSWn_N

IOC