STA369BW datasheet(80/88 Pages) STMICROELECTRONICS

80 / 88 page

STA369BW

80/88

Doc ID 022033 Rev 1

In this case the user can decide, for each filter stage, the right coefficients range. Note that

for a given biquad, the same range will be applied to left and right (channel 1 and channel

2).

The crossover biquad does not have the availability of this feature, maintaining the [-1;1)

range unchanged.

7.24

Miscellaneous registers (address 0x4B, 0x4C)

7.24.1

Rate powerdown enable (RPDNEN) bit (address 0x4B, bit D7)

In the STA369BW, by default, the power-down pin and I2C power-down act on mute

commands to perform the fadeout. This default can be changed so that the fadeout can be

started using the master volume. The RPDNEN bit, when set, activates this feature.

7.24.2

Noise-shaping on DC cut filter enable (NSHHPEN) bit (address 0x4B,

bit D6)

Following the description in Section 7.22, this bit, when set, enables the noise-shaping

technique on the DC cutoff filter. Channels 1 and 2 share the same settings.

7.24.3

Bridge immediate off (BRIDGOFF) bit (address 0x4B, bit D5)

A fadeout procedure is started in the STA369BW once the PWDN function is enabled.

Independently from the fadeout time, after 13 million clock cycles (PLL internal frequency)

the bridge is put in power-down (tristate mode). There is also the possibility to change this

behavior so that the power bridge will be switched off immediately after the PWDN pin is tied

to ground, without waiting for the 13 million clock cycles. The BRIDGOFF bit, when set,

activates this function. Obviously the immediate power-down will generate a pop noise at

the output, therefore this procedure must be used only in case pop noise is not relevant in

the application. Note that this feature works only for hardware PWDN assertion and not for a

power-down applied through the I2C interface. Refer to Section 7.24.5 in order to program a

different number of clock cycles.

RPDNEN

NSHHPEN

BRIDGOFF Reserved

Reserved

CPWMEN

Reserved

PNDLSL[2] PNDLSL[1] PNDLSL[0] Reserved

Reserved

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