isp1504a1 NXP Semiconductors, isp1504a1 Datasheet - Page 9

• Manufacturer Part Number: isp1504a1
• Description: Isp1504a1; Isp1504c1 Ulpi Hi-speed Universal Serial Bus On-the-go Transceiver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
ISP1504A1_ISP1504C1_1
Product data sheet
7.6.2.1 V
7.6.2.2 Session valid comparator
7.6.2.3 Session end comparator
7.6.1 ID detector
7.6.2 V
7.6.3 SRP charge and discharge resistors
Remark: The ISP1504x1 does not include the 5 V charge pump to power V
The ID detector detects which end of the micro-USB cable is plugged in. The detector
must first be enabled by setting the ID_PULLUP register bit to logic 1. If the ISP1504x1
senses a value on ID 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 ISP1504x1 provides three comparators, V
comparator and session end comparator, to detect the V
This comparator is used by hosts and OTG A-devices to determine whether the voltage on
V
comparator is 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 ISP1504x1 is
V
The ISP1504x1 session end comparator determines when V
session end threshold. The B-device uses this threshold to determine when a session has
ended. The session end threshold of the ISP1504x1 is V
The ISP1504x1 provides on-chip resistors for short-term charging and discharging of
V
restore the V
the previous session by setting the DISCHRG_VBUS register bit to logic 1 and waiting for
SESS_END to be logic 1. Then the B-device charges V
register bit to logic 1. The A-device sees that V
threshold and starts a session by turning on the V
•
•
•
•
•
BUS
BUS
A_SESS_VLD
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 the host and which as the peripheral.
V
detection, SRP and HNP.
Resistors to temporarily charge and discharge V
If the micro-B end of the cable is plugged in, the ISP1504x1 will report that ID_GND is
logic 1. The USB link must change to peripheral mode.
If the micro-A end of the cable is plugged in, the ISP1504x1 will report that ID_GND is
logic 0. The USB link must change to host mode.
. These are used by the B-device to request a session, prompting the A-device to
BUS
is at a valid level for operation. The ISP1504x1 threshold for the V
valid comparator
comparators
comparators to determine the V
, with a hysteresis of V
BUS
A_VBUS_VLD
power. First, the B-device makes sure that V
Rev. 01 — 6 August 2007
. Any voltage on V
hys(A_SESS_VLD)
ISP1504A1; ISP1504C1
BUS
BUS
voltage level. This is required for the V
BUS
BUS
below V
.
BUS
valid comparator, session valid
is charged above the session valid
BUS
power.
BUS
. This is required for SRP.
BUS
B_SESS_END
A_VBUS_VLD
ULPI HS USB OTG transceiver
by setting the CHRG_VBUS
voltage level.
BUS
BUS
is below the B-device
is fully discharged from
.
is considered a fault.
© NXP B.V. 2007. All rights reserved.
BUS
BUS
valid
BUS
is high
.
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BUS