Apalis Carrier Board Design Guide
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The USBO1_EN and USBO1_OC# signals are only used when the OTG port is operating in host
mode (Micro-A USB connector is plugged in or the port is configured by software as host only). The
USBO1_EN signal is used to enable the USB bus power supply if it needs to be switchable. A USB
compliant design needs to detect overcurrent on the USB bus power supply and switch the power
off should an over-current condition occur. The USBO1_OC# signal is used to signal to the host
controller that an over-current condition has occurred. This signal is active-low and requires a pull-
up resistor on the baseboard.
Figure 21: USB 3.0 OTG reference schematic
The reference schematic for the USB 3.0 OTG is compliant with the USB 3.0 specifications. In the
specifications, there can be found the following cable assemblies:
USB 3.0 Standard-A to USB 3.0 Standard-B Cable (RX and TX crossed in the cable)
USB 3.0 Standard-A to USB 3.0 Micro-B Cable (RX and TX crossed in the cable)
USB 3.0 Micro-A to USB 3.0 Micro-B Cable (RX and TX crossed in the cable)
USB 3.0 Micro-A to USB 3.0 Standard-B Cable (RX and TX crossed in the cable)
Adapter cables such as from Micro-A plug to a Standard-A socket (known as OTG cables) are not
in the specifications. Nevertheless, the cable assemblies above imply that the OTG cable need to
have the RX and TX lines strait (not crossed). Unfortunately, there are USB 3.0 OTG cables on the
market that crosses the RX and TX lines. These cables are not compatible with the reference
schematic. Only OTG cables that are not crossing the SuperSpeed signals are compatible. The
non-compatible adapter cables often are promoted as OTG cables for the Samsung Galaxy Note 3
cellphone. The Micro-A plug of these cables also have a wrong shape. They are shaped as Micro-B
plug even though it is a Micro-A plug.
2.5.2.2
USB 2.0 Client Schematic Example
If the USBO1 port is used only as high-speed client interface (e.g. if only used as debugging
interface), a simplified schematic diagram is necessary.
GREEN
LED1
330R
R1
GND
90R@100MHz
1
2
3
4
L1
2A
220R@100MHz
L2
1003-005-23100
VCC
1
D-
2
D+
3
ID
4
GND
5
SSTX-
6
SSTX+
7
GND DRAIN
8
SSRX-
9
SSRX+
10
SHIELD
S1
SHIELD
S2
X2
USBO1[0..5]
USB_CTRL[0..3]
USBO1_D_N
USBO1_D_P
USBO1_SSTX_N
USBO1_SSTX_P
USBO1_SSRX_N
USBO1_SSRX_P
TPS2052BD
V_IN
2
EN_1
3
OUT_1
7
OC_1#
8
IC1A
1nF
50V
C4
GND_USBO1
100nF
16V
C2
GND
100uF
10V
+C3
GND
2A
220R@100MHz
L4
USBO1_VBUS
USBO1_ID
USBO1_OC#
USBO1_EN
USBO1_D_CON_N
USBO1_D_CON_P
GND
0R
R2
USBO1_ID
RCLAMP0504S
1
2
3
4
5
6
D3
4A
39R@100MHz
L3
100nF
C1
SHIELD
5V_ESD
SHIELD
TPD2EUSB30DRTR
1
3
2
D+
D-
D1
TPD2EUSB30DRTR
1
3
2
D+
D-
D2
GND
GND
R3
100K
3.3V_SW
SHIELD
VCC_USBO1
VCC_USBO1
GND_USBO1
GND_USBO1
R4
100K
3.3V_SW
5V_SW
5V_SW
Optional
MM70-314-310B1
USBO1_VBUS
60
Apalis - USB
3 of 25
USBH2_D-
82
80
USBO1_SSTX-
70
USB
68
USBO1_ID
72
USBO1_SSRX-
64
USB
62
USBH_EN
84
USBH3_D-
88
86
USBH4_D-
100
98
USBO1_D-
76
74
USBH_OC#
96
USBH4_SSTX-
104
USB
106
USBH4_SSRX-
92
USB
94
USBO1_OC#
262
USBO1_EN
274
X1C
USBO1_OC#
USBO1_EN
USBO1_D_N
USBO1_D_P
USBO1_SSTX_N
USBO1_SSTX_P
USBO1_SSRX_N
USBO1_SSRX_P
USBO1_ID
USBO1_VBUS
VCC_USBO1
TPS2052BD
GND
1
EN_2
4
OC_2#
5
OUT_2
6
IC1B
GND
GND
R5
100K
GND