Tripath Technology, Inc. – Preliminary Technical Information
Output Characteristics
The TCD6001 outputs consist of four pairs of complementary 1-bit digital data streams, one pair per audio
channel as well as stereo line-out / head phone amplifier. The complementary 1-bit digital streams switch
from 0V to 5V (+/- 10%) and constitute a pulse-density-modulated (PDM) form of the audio signal. They are
used to drive Tripath power stages in a switching amplifier configuration. The head phone amplifier is
capable of driving XXmW into 32 ohm loads.
The output power of a power stage can be expressed as V2 /R, V being the voltage amplitude of the power
stage output and R the speaker input impedance, typically 4 to 8 ohms.
The audio signal is recovered by filtering the PDM signal through an LC filter located at the inputs of the
speaker. The following figure shows the power stage output waveform and the filtered signal at the speaker
inputs:
Typical waveform at power stage output
Typical waveform at speaker inputs after LC filtering
TCD6001 outputs are pulse density modulated outputs. Their frequency varies constantly over time and can
typically reach a maximum value of 800 kHz.
A Mute output (HMUTE) can be connected to all 4 power stages to force them into a tri-state mode when a
hard mute condition is encountered. The HMUTE output can be programmed to be either active-high or
active-low via the pin HMUTE_SET. The HMUTE_SET input range is 0 to 5V with 3.3V compliant inputs.
Setting HMUTE_SET will result in HUMTE being low during a fault condition. Setting HMUTE_SET high will
result in HMUTE being high during a fault condition.
An overload is detected whenever the combination of input signal amplitude and volume programmed in the
TCD6001 results in output signal saturation and distortion. The OVRLDB pin goes active low when this
condition occurs.
A test output pin is also provided (TST_EN) for external testing purposes. Setting bit D4 in control register
74h will force this output to an active high state.
The HMUTE, OVRLDB, SLEEP_OUTB, AM_OUT and TST_EN outputs are 5V digital outputs.
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TCD6001 – JL/Rev. 0.9/07.05
TRIPATH [ TRIPATH TECHNOLOGY INC. ]
