Texas Instruments TPA3223EVM, User Manual, Page: 10 / 33

3 Hardware Configuration
3.1 Indicator Overview (OTW_CLIP and FAULT)
The TPA3223EVM is equipped with LED indicators that illuminate when the FAULT or OTW_CLIP pin goes low.
See
Table 3-1 and the TPA3223 data sheet ( SLASEF0 ) for more details.
Table 3-1. Fault and Clip Overtemperature Status
FAULT
LED Status
OTW_CLIP
LED Status
Description
ON ON
Overtemperature (OTE) or overload (OLP) or undervoltage (UVP). Junction temperature higher
than 125°C (Overtemperature warning)
ON OFF Overload (OLP) or undervoltage (UVP). Junction temperature lower than 125°C
OFF ON Junction temperature higher than 125°C (Overtemperature warning)
OFF OFF Junction temperature lower than 125°C and no OLP or UVP faults (normal operation)
3.2 PWM Frequency Adjust
The TPA3223EVM allows for three oscillator frequency options by external configuration of the FREQ_ADJ pin.
The frequency adjust can be used to reduce interference problems while using a radio receiver tuned within the
AM band. These values must be chosen so that the nominal and the lower value switching frequencies together
results in the fewest cases of interference throughout the AM band. The oscillator frequency can be selected by
the value of the FREQ_ADJ resistor connected to GND in Primary mode according to
Table 3-2 .
Table 3-2. Frequency Adjust Primary Mode Selection (J16)
FREQ_ADJ (J16) Mode Resistor Selected to GND or Pullup
Primary MODE 10 kΩ
Primary MODE AM1 30 kΩ
Primary MODE AM2 49.9 kΩ
Peripheral MODE Pullup to 5 V
Selecting Peripheral Mode configures the OSC_I/O pins as inputs to be synchronized from an external
differential clock. In a Primary or Peripheral system, interchannel delay is automatically set up between the
switching phases of the audio channels, which can be illustrated by no idle channels switching at the same
time. The audio output will not be influenced, but the switch timing is changed to minimize noise coupling
between audio channels through the power supply. This configuration will optimize audio performance and result
in better operating conditions for the power supply. The inter-channel delay will be set up for a peripheral device
depending on the polarity of the OSC_I/O connection such that peripheral mode 1 (secondary) is selected by
connecting the OSC_I/O of the Primary device with the OSC_I/O of the peripheral device with the same polarity
(+ to + and – to –), while peripheral mode 2 (tertiary) is selected by connecting the OSC_I/Os with the inverse
polarity (+ to – and – to +).
Hardware Configuration www.ti.com
10 TPA3223 Evaluation Module SLAU874 – OCTOBER 2022
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