1998 Oct 06

34

Philips Semiconductors

Preliminary specification

Universal Serial Bus (USB)

Digital-to-Analog Converter (DAC)

UDA1321

USB-DAC UDA1321/N101 (FIRMWARE SW 2.1.1.7)

The following items are different for the UDA1321/N101 compared to the general content of this data sheet:

• Volume control

• Treble control

• Power management.

Table 10 Volume control characteristics

The treble control is available for the master channel of the UDA1321. Treble can be regulated in three modes: minimum,

flat and maximum mode. The preferred mode is selected via the configuration map. The corner frequency is 3000 Hz for

the minimum mode and 1500 Hz for the maximum mode. The treble range is from 0 to 6 dB (discrete steps

0, 4 and 6 dB). It should be noted that the negative treble values as defined in the

“USB Device Class Definition for Audio

Devices” are not supported by the UDA1321; the 0 dB value is returned as 0 dB. Table 4 gives the mapping of the

bTreble value upon the actual treble setting of the USB DAC.

wVOLUME

VOLUME USB SIDE

(dB)

VOLUME USB DAC

(dB)

B15

B14

B13

B12

B11

B10

B9

B8

00000000

0

0

11111111

0

0

11111110

−1

−1

11111101

−2

−2

11111100

−3

−3

11111011

−4

−4

11111010

−5

−5

11111001

−6

−6

11111000

−7

−7

11110111

−8

−8

11110110

−9

−9

...

...

...

...

...

...

...

...

...

...

11000101

−58

−58

11000100

−59

−59

11000011

−60

−60

11000010

−61

−∞

11000001

−62

−∞

...

...

...

...

...

...

...

...

...

...

10000000

−∞

−∞