USB3320 datasheet(5/70 Pages) MICROCHIP

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DS00001792B-page 5

USB3320

The USB3320 includes an integrated 3.3V Low Drop Out (LDO) regulator that may optionally be used to generate 3.3V

from power applied at the VBAT pin. The voltage on the VBAT pin can range from 3.1 to 5.5V. The regulator dropout

voltage is less than 100mV which allows the transceiver to continue USB signaling when the voltage on VBAT drops to

3.1V. The USB transceiver will continue to operate at lower voltages, although some parameters may be outside the

limits of the USB specifications. If the user would like to provide a 3.3V supply to the USB3320, the VBAT and VDD33

pins should be connected together as described in Section 5.5.1.

The USB3320 also includes integrated pull-up resistors that can be used for detecting the attachment of a USB Charger.

By sensing the attachment to a USB Charger, a product using the USB3320 can charge its battery at more than the

500mA allowed when charging from a USB Host. Please see Microchip Application Note AN 19.7 - Battery Charging

Using Microchip USB Transceivers for more information on battery charging.

In USB UART mode, the USB3320 DP and DM pins are redefined to enable pass-through of asynchronous serial data.

The USB3320 can only enter UART mode when the user programs the part into this mode, as described in

Section 6.5.1.

In USB audio mode, a switch connects the DP pin to the SPK_R pin, and another switch connects he DM pin to the

SPK_L

pin. These switches are shown in the lower left-hand corner of Figure 5.1. The USB3320 can be configured to

enter USB audio mode as described in Section 6.5.2. In addition, these switches are on when the RESETB pin of the

USB3320 is asserted. The USB audio mode enables audio signaling from a single USB port of connection, and the

switches may also be used to connect Full Speed USB from another transceiver onto the USB cable.

1.2

Reference Documents

• Universal Serial Bus Specification, Revision 2.0, April 27, 2000

• On-The-Go Supplement to the USB 2.0 Specification, Revision 2.0, May 8, 2009

• USB Specification Revision 2.0 "Pull-up/pull-down resistors" ECN (27% Resistor ECN)

• USB 2.0 Transceiver Macrocell Interface (UTMI) Specification, Version 1.02, May 27, 2000

• UTMI+ Specification, Revision 1.0, February 25, 2004

• UTMI+ Low Pin Interface (ULPI) Specification, Revision 1.1, October 20th, 2004

• Technical Requirements and Test Methods of Charger and Interface for Mobile Telecommunication Terminal

Equipment (Chinese Charger Specification Approval Draft 11/29/2006)

USB3320 数据表(PDF) 5 Page - Microchip Technology