USB3320C-EZK Standard Microsystems (SMSC), USB3320C-EZK Datasheet - Page 40

• Manufacturer Part Number: USB3320C-EZK
• Description: USB PHY
• Manufacturer: Standard Microsystems (SMSC)

Specifications of USB3320C-EZK

• Lead Free Status / RoHS Status: Compliant

Revision 1.0 (07-14-09)
5.9
RESETB
RESETB
X
0
1
Note: ChargerPullupEnableDP and ChargerPullupEnableDM are enabled in the
Note: The USB3320 supports “USB Digital Audio” through the USB protocol in ULPI and USB Serial
The USB3320 provides two low resistance analog switches that allow analog audio to be multiplexed
over the DP and DM terminals of the USB connector. The audio switches are shown in
electrical characteristics of the USB Audio Switches are provided in
During normal USB operation the switches are off. When USB Audio is desired the switches can be
turned “on” by enabling the SpkLeftEn, SpkRightEn, or MicEn bits in the
described in
enabled by asserting the RESETB pin or removing the voltage at VDD18 as shown in
using the USB switches, VDD18 is not required, but 3.3V must be present at VDD33. The integrated
3.3V LDO regulator may be used to generate VDD33 from power applied at the VBAT pin.
Note: SpkLeftEn, SpkRightEn, and MicEn are enabled in the
In addition to USB Audio support the switches can also be used to multiplexed a second FS USB
transceiver to the USB connector. The signal quality will be degraded slightly due to the “on” resistance
of the switches. The USB3320 single-ended receivers described in
either USB Audio switch is enabled.
The USB3320 does not provide the DC bias for the audio signals. The SPK_R and SPK_L pins should
be biased to 1.65V when audio signals are routed through the USB3320. This DC bias is necessary
to prevent the audio signal from swinging below ground and being clipped by ESD Diodes.
When the system is not using the USB Audio switches, the SPK_R and SPK_L pins should not be
connected.
USB Audio Support
0
1
Management
modes described in
Section
6.5.2. These bits are disabled by default. The USB Audio Switches can also be
register.
Table 5.9 USB Audio Switch Enable
Table 5.8 USB Weak Pull-up Enable
VDD18
ChargerPullupEnableDP
DP PULLUP ENABLE
Section
0
1
1
DATASHEET
6.
0
40
DP SWITCH ENABLE
SpkLeftEn
Highly Integrated Full Featured Hi-Speed USB 2.0 ULPI Transceiver
1
1
Carkit Control
ChargerPullupEnableDM
DM PULLUP ENABLE
Table
Section 5.2.1
4.8.
DM SWITCH ENABLE
Carkit Control
SpkRightEn or MicEn
register.
0
are disabled when
USB IO & Power
Table
Figure
1
1
SMSC USB3320
register as
5.9. While
Datasheet
5.1. The