Datasheet

PCM2704C, PCM2705C
PCM2706C, PCM2707C
www.ti.com SBFS036A –AUGUST 2011–REVISED JULY 2012
USB Interface
Control data and audio data are transferred to the PCM2704C/5C/6C/7C via the D+ pin (pin 9 for the
PCM2704C/5C, pin 23 for the PCM2706C/7C) and D– pin (pin 8 for the PCM2704C/5C, pin 22 for the
PCM2706C/7C). D+ should be pulled up with a 1.5-kΩ (±5%) resistor. To avoid back voltage in self-powered
operation, the device must not provide power to the pull-up resistor on D+ while V
BUS
of the USB port is inactive.
All data to/from the PCM2704C/5C/6C/7C are transferred at full speed. The information shown in Table 5 is
provided in the device descriptor. Some parts of the device descriptor can be modified through external ROM
(PCM2704C/6C) or SPI™ (PCM2705C/7C).
Table 5. Device Descriptor
DEVICE DESCRIPTOR DESCRIPTION
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)
0x27C4/0x27C5/0x27C6/0x27C7 (These values correspond to the model number, and the value can
Product ID
be modified.)
Device release number 1.0 (0x0100)
Number of configurations 1
Vendor strings BurrBrown from Texas Instruments (default value, can be modified)
Product strings USB AUDIO DAC (default value, can be modified)
Serial number Not supported
The information given in Table 6 is contained in the configuration descriptor. Some parts of the configuration
descriptor can be modified through external ROM (PCM2704C/6C) or SPI (PCM2705C/7C).
Table 6. Configuration Descriptor
CONFIGURATION DESCRIPTOR DESCRIPTION
Interface Three interfaces
0x80 or 0xC0 (bus-powered or self-powered, depending on PSEL; no remote wake up. This value can
Power attribute
be modified.)
0x0A, 0x32, or 0xFA (20 mA for self-powered, 100 mA or 500 mA for bus-powered, depending on
Max power
PSEL and HOST. This value can be modified.)
The information listed in Table 7 is contained in the string descriptor. Some parts of the string descriptor can be
modified through external ROM (PCM2704C/6C) or SPI (PCM2705C/7C).
Table 7. String Descriptor
STRING DESCRIPTOR DESCRIPTION
#0 0x0409
#1 BurrBrown from Texas Instruments (default value, can be modified)
#2 USB AUDIO DAC (default value, can be modified)
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Product Folder Link(s): PCM2704C PCM2705C PCM2706C PCM2707C