Texas Instruments TPA3220, Руководство пользователя

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Hardware Configuration
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10 SLAU754A – January 2018 – Revised August 2019
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TPA3220 Evaluation Module
3 Hardware Configuration
3.1 Indicator Overview (OTW_CLIP and FAULT)
The TPA3220EVM is equipped with LED indicators that illuminate when the FAULT or OTW_CLIP pin
goes low. See
Table 3 and TPA3220 100-W Peak HD-Audio, Analog-Input, Class-D for more details.
Table 3. 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 (OTE warning)
ON OFF Overload (OLP) or undervoltage (UVP). Junction temperature lower than 125°C
OFF ON Junction temperature higher than 125°C (OTE warning)
OFF OFF Junction temperature lower than 125°C and no OLP or UVP faults (normal operation)
3.2 PWM Frequency Adjust
The TPA3220EVM 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 should be chosen such 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
master mode according to
Table 4 .
Table 4. Frequency Adjust Master Mode Selection (J16)
FREQ_ADJ (J16) Mode
Resistor Selected to
GND or Pullup
PWM Frequency
Master MODE 49.9 k Ω 600 kHz
Master MODE AM1 30 k Ω 533 kHz
Master MODE AM2 10 k Ω 480 kHz
Slave MODE Pullup to 5 V N/A
Selecting Slave Mode configures the OSC_I/O pins as inputs to be slaved from an external differential
clock. In a master or slave 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.
This will not influence the audio output, but only the switch timing to minimize noise coupling between
audio channels through the power supply. This will optimize audio performance and result in better
operating conditions for the power supply. The inter-channel delay will be set up for a slave device
depending on the polarity of the OSC_I/O connection such that slave mode 1 is selected by connecting
the OSC_I/O of the master device with the OSC_I/O of the slave device with the same polarity (+ to +
and – to –), while slave mode 2 is selected by connecting the OSC_I/Os with the inverse polarity (+ to –
and – to +).