ISP1705AETTM STEricsson, ISP1705AETTM Datasheet - Page 12

• Manufacturer Part Number: ISP1705AETTM
• Manufacturer: STEricsson

Specifications of ISP1705AETTM

• Lead Free Status / RoHS Status: Compliant

ISP1705_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 ISP1705
senses a state of the ID pin that is different from the previously reported state, 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 ISP1705 provides three comparators to detect the V
comparators are explained in the following subsections.
This comparator is used 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 ISP1705 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.
BUS
BUS
•
•
•
•
•
BUS
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 ISP1705
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 ISP1705 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 ISP1705 minimum threshold for the V
valid comparator
comparators
comparators to determine the V
Rev. 02 — 21 January 2009
BUS
weakPU(ID)
BUS
below this threshold is considered invalid.
voltage level. This is required for the V
BUS
) permanently enabled to avoid the
BUS
is below the B-device session end
ULPI Hi-Speed USB transceiver
. This is required for SRP.
BUS
voltage level. The
© ST-NXP Wireless 2009. All rights reserved.
ISP1705
BUS
is high
BUS
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valid
BUS