Datasheet

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SLAS328 − SEPTEMBER 2001
6
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functional description (continued)
digital interpolation filter
The 24-bit high-performance linear phase FIR interpolation filter up-samples the input digital data at a rate of
2 times (quad speed mode = 176.4kHz or 192kHz), 4 times (double speed mode = 88.2 kHz or 96 kHz), or 8
times (normal mode = 44.1 kHz or 48 kHz) the incoming sample rate. This filter provides very low pass-band
ripple and optimized time domain transient response for accurate music reproduction.
digital PWM modulator
The interpolation filter output is sent to the modulator. This modulator consists of a high performance fourth order
digital noise shaper and a PCM-to-PWM converter. Following the noise shaper, the PCM signal is fed into a very
low distortion PCM-to-PWM conversion block, buffered, and output from the chip. The modulation scheme is
based on a 2-state control of the H-bridge output.
control, status, and operational modes
The TAS5010 control section consists of several control-input pins. Three serial mode pins (MOD0, MOD1, and
MOD2) are provided to select various serial data formats. During normal operating conditions if any of the
MOD0, MOD1, or MOD2 pins changes state, a reset sequence is initiated. Also provided are separate
power-down (PDN
), reset (RESET), and mute (MUTE) pins.
power up
At power up the VALID_L and VALID_R pins are asserted low and the PWM outputs go to the hard mute state
in which the P outputs are held low and the M outputs are held high. Following initialization, the TAS5010 comes
up in the operational state (differential PWM audio). There are two cases of power-up timing. The first case is
shown in Figure 1 with RESET
preceding PDN. The second case is shown in Figure 2 with PDN preceding
RESET
.
Initialization Time = 100 ms max
RESET
PDN
VALID_L
VALID_R
Figure 1. Power-Up Timing (RESET Preceding PDN)
Initialization Time = 5 ms max
RESET
PDN
Greater Than 16 MCLK Periods
VALID_L
VALID_R
Figure 2. Power-Up Timing (PDN Preceding RESET)