ISP1508BET STEricsson, ISP1508BET Datasheet - Page 16

• Manufacturer Part Number: ISP1508BET
• Manufacturer: STEricsson

Specifications of ISP1508BET

• Lead Free Status / RoHS Status: Supplier Unconfirmed

NXP Semiconductors
ISP1508A_ISP1508B_2
Product data sheet
8.7.2.1 V
8.7.2.2 Session valid comparator
8.7.2.3 Session end comparator
8.7.1 ID detector
8.7.2 V
8.7 OTG module
This module contains several sub-blocks that provide all the functionality required by the
USB OTG specification. Specifically, it provides the following circuits:
The ID detector detects which end of the micro-USB cable is plugged in. The ID detector
must first be enabled by setting the ID_PULLUP register bit to logic 1. If the ISP1508
senses a value on the ID pin that is different from the previously reported value, an
RXCMD status update will be sent to the USB link, or an interrupt will be asserted.
The ID pin has a weak pull-up resistor (R
floating condition.
The ISP1508 provides three comparators to detect the V
comparators are explained in the following subsections.
This comparator is used only by hosts and A-devices to determine whether the voltage on
V
comparator is 4.4 V. Any voltage on V
During power-up, it is expected that the comparator output will be ignored.
The session valid comparator is a TTL-level input that determines when V
enough for a session to start. Peripherals, A-devices and B-devices use this comparator to
detect when a session is started. The A-device also uses this comparator to determine
when a session is completed. The session valid threshold of the ISP1508 is between
0.8 V to 2.0 V.
The session end comparator determines when V
threshold of 0.2 V to 0.8 V. The B-device uses this threshold to determine when a session
has ended.
•
•
•
•
•
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BUS
BUS
BUS
From DP (2.7 V level) to DATA1 (V
The ID detector to sense the ID pin of the micro-USB cable. The ID pin dictates which
device is initially configured as a host and which as a peripheral.
V
detection, SRP and HNP.
Resistors to temporarily charge and discharge V
If the micro-B end of the cable is plugged in (or nothing is plugged in), the ISP1508
will report that ID_GND is logic 1. The USB link must be in the B-device state.
If the micro-A end of the cable is plugged in, the ISP1508 will report that ID_GND is
logic 0. The USB link must be in the A-device state.
BUS
is at a valid level for operation. The ISP1508 minimum threshold for the V
valid comparator
comparators
comparators to determine the V
Rev. 02 — 13 March 2008
BUS
CC(I/O)
weakPU(ID)
BUS
below this threshold is considered invalid.
level) for the UART RXD signaling path.
ISP1508A; ISP1508B
voltage level. This is required for the V
BUS
) permanently enabled to avoid the
BUS
is below the B-device session end
. This is required for SRP.
BUS
ULPI HS USB OTG transceiver
voltage level. The
© NXP B.V. 2008. All rights reserved.
BUS
is high
BUS
valid
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BUS