PCM2704,PCM2705

PCM2706,PCM2707

SLES081A − JUNE 2003 – REVISED MAY 2004

www.ti.com

16

USB INTERFACE

Control data and audio data are transferred to the PCM2704/5/6/7 via D+ (pin 9 for PCM2704/5, pin 23 for

PCM2706/7) and D– (pin 8 for PCM2704/5, pin 22 for PCM2706/7). D+ should be pulled up with a 1.5-k

Ω (±5%)

resistor

. To avoid back voltage in self-powered operation, the device must not provide power to the pullup resistor

All data to/from the PCM2704/5/6/7 are transferred at full speed. The following information is provided in the device

descriptor. Some parts of the device descriptor can be modified through external ROM (PCM2704/6), SPI

(PCM2705/7), or internal mask ROM on request.

Table 3. Device Descriptor

USB revision

1.1 compliant

Device class

0x00 (device defined interface level)

Device subclass

0x00 (not specified)

Device protocol

0x00 (not specified)

Max packet size for endpoint 0

8 bytes

Vendor ID

0x08BB (default value, can be modified)

Product ID

0x2704/0x2705/0x2706/0x2707 (These values correspond to the model number, and the value can be

modified.)

Device release number

1.0 (0x0100)

Number of configurations

1

Vendor strings

“Burr-Brown from TI” (default value, can be modified)

Product strings

“USB Audio DAC” (default value, can be modified)

Serial number

Not supported

The following information is contained in the configuration descriptor. Some parts of the configuration descriptor can

be modified through external ROM (PCM2704/6), SPI (PCM2705/7), or on request.

Table 4. Configuration Descriptor

Interface

Three interfaces

Power attribute

0x80 or 0xC0 (bus-powered or self-powered, depending on PSEL; no remote wake up. This value can be modified.)

Max power

0x0A, 0x32 or 0xFA (20 mA for self-powered, 100 mA or 500 mA for bus-powered, depending on PSEL and HOST. This

value can be modified.)

The following information is contained in the string descriptor. Some parts of the string descriptor can be modified

through external ROM (PCM2704/6), SPI (PCM2705/7), or on request.

Table 5. String Descriptor

#0

0x0409

#1

Burr-Brown from TI (default value, can be modified)

#2

USB Audio DAC (default value, can be modified)