isp1161bm NXP Semiconductors, isp1161bm Datasheet - Page 39

• Manufacturer Part Number: isp1161bm
• Description: Isp1161 Full-speed Universal Serial Bus Single-chip Host And Device Controller
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 09567
Product data
9.8 Overcurrent detection and power switching control
A downstream port provides 5 V power supply to the V
hardware functions to monitor the downstream ports loading conditions and control
their power switching. These hardware functions are implemented by the internal
power switching control circuit and overcurrent detection circuit. Pins H_PSW1 and
H_PSW2 are power switching control output pins (active LOW and open drain) for
downstream port 1 and 2, respectively. Pins H_OC1 and H_OC2 are overcurrent
detection input pins for downstream ports 1 and 2, respectively. Let H_PSWn denote
either H_PSW1 or H_PSW2 and H_OCn denote either H_OC1 or H_OC2.
Figure 34
Fig 33. Use of 15 k pull-down resistors on downstream ports.
Fig 34. Downstream port power management scheme.
Using either internal or external 15 k resistors.
shows the ISP1161 downstream port power management scheme.
Configuration
HcHardware
( 5 V or 3.3 V)
H_PSWn
H_OCn
Rev. 02 — 13 December 2002
V CC
internal
15 k
(2 )
bit 12
ISP1161
Full-speed USB single-chip host and device controller
OC detect
regulator
MGT957
D
D
22
22
ISP1161
OC select
1
0 Reg
PSW
C/L
HC CORE
© Koninklijke Philips Electronics N.V. 2002. All rights reserved.
BUS
external
15 k
Configuration
(2 )
HcHardware
. The ISP1161 has built-in
V BUS
bit 10
47 pF
(2 )
connector
MGT959
ISP1161
USB
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