3.5.2.2 Channel Control Section
Each channel has the same setting selections: Hi-Z, Mute, Unmute, Volume, Line-out mode and Speaker mode.
The drop down menu allows user to select either Hi-Z, Mute or Unmute state of each channel.
The volume slide controls the digital gain of each channel.
The default setting for each channel is speaker mode. If line-out is used, select Line Output button.
Figure 3-11. Channel Control Section
3.5.2.3 Miscellaneous Control Section
There are miscellaneous settings that are available on the GUI for easy access.
OSR is oversampling bit. For lower idle noise 64X OSR is set as default. For wider bandwidth, 128X OSR can be
used. 64X OSR is recommended.
TAS6424E-Q1 supports parallel Bridge-Tied Load. Channels 1 and 2 can be one PBTL channel and channels
3 and 4 can be the other. Before setting a set of channels to PBTL mode, connect the (+) terminals as PBTL
channel (+) and the (-) terminals as PBTL channel (-). Then connect the speaker (+) to the PBTL channel (+)
and connect the speaker (-) to the PBTL channel (-).
The over-current has two levels. The lower level is 1. The default is level 2. When running at lower output
current, OC level can be set to 1. I2S and TDM are automatically detected. Use the pull down menu from “Input
Format” box to manually select the audio format.
If sampling frequency is greater than 48 kHz, select 96 kHz from the “Input FS” pull down.
Over-temperature warning can be programmable, use the pull down menu to choose the OTW temperature. The
default setting is 120°C.
The output switching frequency (FSW) or Pulse Width Modulation frequency (PWM) is set at 2.1 MHz. The
pull-down menu on the PWM FRQ box is used to choose a lower FSW. LC value should be adjusted when FSW
is changed.
The offset phase for each channel is set at 45 degrees. This helps lower the ripple current on the power supply
as not all the channels switch at the same time. To choose a different phase offset, use the pull-down menu on
the “Phase” box.
There are four gain settings in TAS6424E-Q1: low, normal, high and maximum. The default setting is high.
However, the recommended setting is normal for lower noise performance for driving speakers at
14.4 VDC. The gain setting is selectable via the drop down menu in the ”Gain” box.
The volume slew rate is measured with sampling frequency. The default setting is 1 period of sampling
frequency (FSYNC or FS). This rate is selectable from 1 to 8 sampling periods with the drop down menu
under “Vol Rate” box.
Software Overview
SLOU553 – MAY 2021
TAS6424E-Q1 EVM
13
Copyright © 2021 Texas Instruments Incorporated
