14

DS640PP4

CS44L11

DC-blocking capacitor during power transients. On power transitions, the output will quickly change to the

bias point; however, if the DC-blocking capacitor still has a full charge, as in short power cycles, the tran-

sition will be very small, often inaudible. Refer to Section 6.4.

4.1.4

Ramp-Up Bypass (RUPBYP)

Default = 0

0 - Normal

1 - Bypass

Function:

When in normal mode, the duty cycle of the output PWM signal is increased at a rate determined by the

Ramp Speed variable (RMP_SPx). Normal mode is used in Single-Ended applications to reduce pops in

the output caused by the DC-blocking capacitor. When the ramp-up function is bypassed in Single-Ended

applications, there will be an abrupt change in the output signal. Refer to Section 6.4.

4.1.5

Ramp-Down Bypass (RDNBYP)

Default = 0

0 - Disabled

1 - Enabled

Function:

When in normal mode, the duty cycle of the output PWM signal is decreased at a rate determined by the

Ramp Speed variable (RMP_SPx). Normal mode is used in Single-Ended applications to reduce pops in

the output caused by the DC-blocking capacitor and changes in bias conditions. When the ramp-down

function is bypassed in Single-Ended applications, there will be an abrupt change in the output signal.

Refer to Section 6.4.

4.2

Channel A Volume Control (address 03h) (VOLA)

4.3

Channel B Volume Control (address 04h) (VOLB)

Default = 0 dB (No attenuation)

Function:

The Volume Control registers allow independent control of the signal levels in 1 dB increments from +18 to

-96 dB. Volume settings are decoded using a 2’s complement code, as shown in Table 2. The volume

changes are implemented as dictated by the Soft and Zero Cross bits. All volume settings less than -96 dB

are equivalent to muting the channel via the ATAPI bits (see Section 4.8.2).

Note:

All volume settings greater than +18 dB are interpreted as +18 dB.

76

543

21

0

VOLx7

VOLx6

VOLx5

VOLx4

VOLx3

VOLx2

VOLx1

VOLx0

00

000

00

0

Binary Code

Decimal Value

Volume Setting

00001100

12

+12 dB

00000111

7

+7 dB

00000000

0

0 dB

11000100

-60

-60 dB

10100110

-90

-90 dB

Table 2. Example Volume Settings