ISP1362EE/01 PHILIPS [NXP Semiconductors], ISP1362EE/01 Datasheet - Page 47

• Manufacturer Part Number: ISP1362EE/01
• Description: Single-chip Universal Serial Bus On-The-Go controller
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
9397 750 12337
Product data
12.8.1 Using internal OC detection circuit
12.8.2 Using external OC detection circuit
An application using the internal OC detection circuit and internal 15 k pull-down
resistors is shown in
while DPn denotes either OTG_DP1 or H_DP2. In this example, the HC Driver must
set both AnalogOCEnable and ConnectPullDown_DS1 (bit 10 and bit 12 of the
HcHardwareConfiguration register, respectively) to logic 1.
When H_OCn detects an overcurrent status on a downstream port, H_PSWn will
output HIGH to turn off the +5 V power supply to the downstream port V
there is no such detection, H_PSWn will output LOW to turn on the +5 V power
supply to the downstream port V
In general applications, you can use a P-channel MOSFET as the power switch for
V
V
the drain and source poles can be called the overcurrent trip voltage. For the internal
overcurrent detection circuit, a voltage comparator has been designed-in, with a
nominal voltage threshold of 75 mV. Therefore, when the overcurrent trip voltage ( V)
exceeds the voltage threshold, H_PSWn will output a HIGH level to turn off the
P-channel MOSFET. If the P-channel MOSFET has R
threshold will be 500 mA. The selection of a P-channel MOSFET with a different
R
When V
power supply, the internal OC detection circuit cannot be used. An external
OC detection circuit must be used instead. Nevertheless, regardless of V
connection, an external OC detection circuit can be used from time to time. To use an
Fig 23. Using internal OC detection circuit.
BUS
BUS
DSon
. Connect the +5 V power supply to the drain pole of the P-channel MOSFET,
(1) 100 F for the host port or 4.7 F for the OTG port.
to the source pole, and H_PSWn to the gate pole. This voltage drop ( V) across
will result in a different overcurrent threshold.
004aaa148
chassis
chassis
CC
V BUS
GND
DM
DP
(pin 56) is connected to the +3.3 V power supply instead of the +5 V
1
2
3
4
5
6
Rev. 03 — 06 January 2004
DGND
DGND
Figure
C41 (1)
23, where DMn denotes either OTG_DM1 or H_DM2,
BUS
DGND
.
C17
0.1 F
P_channel
MOSFET
FB2
drain
source
Single-chip USB OTG controller
DSon
gate
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
of 150 m , the overcurrent
C18
0.1 F
ISP1362
R31
10 k
BUS
CC
H_PSWn
V DD_5V
PSU_5V
H_OCn
. When
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