Quick Start List for Stand-Alone Operation
2-3
Operation
the MODE pin is high. When the MODE pin is low, the MODEB pin drives
high. If the MODEB pin is connected to the shutdown pin on an external
TPA6110A2, the TPA6110A2 mutes when the class-D outputs are active.
2.1.6
Power Up
1) Verify correct voltage and input polarity and set the external power supply
to ON. The EVM should begin operation.
2) Adjust the signal source level as needed.
Adjusting the Speaker Volume
3) Adjust the speaker (connected across OUT+ and OUT–) volume as
needed by turning the P1 potentiometer in the clockwise direction to
increase the volume. Conversely, turn P1 in the counterclockwise
direction to decrease the volume. Refer to Table 3–2 in the Reference
section for volume control settings.
Setting Maximum Headphone Volume
4) Set the maximum possible VAROUT volume by adjusting P2. Turning P2
in the clockwise direction sets the limit higher. Turning P2 in the
counterclockwise direction lowers the VAROUT volume limit. Refer to
Table 3–3 in the Reference section for volume control settings.
Adjusting the Headphone Volume
5) Adjust the VAROUTL and VAROUTR (headphone) volume by adjusting
potentiometer P3. The headphone volume (VAROUT) is set by the
difference between VOLUME speaker voltage and VARDIFF voltage.
Turning P3 in the clockwise direction decreases the voltage on the
VARDIFF terminal and the VAROUT (headphone) volume increases.
Conversely, turning P3 in the counterclockwise direction increases the
VARDIFF voltage and decreases the VAROUT volume. Refer to Table 3–3
in the Reference section for volume control settings.
Test Pins for External HP Driver, Regulated Output, Speaker Volume, and
Headphone Volume
-
T1 – VAROUTR
-
T2 – VAROUTL
-
T3 – AGND
-
T4 – AVDD – 5 V regluated voltage capable of 120 mA output
-
T5 – VOLUME – Speaker volume
-
T6 – VARMAX – Max headphone volume
-
T7 – VARDIFF – Headphone volume
2.1.7
External Headphone Amplifier Special Considerations
1) Refer to the TPA3002D2 data sheet or Figure 3–2 for proper pin
connections.
2) Noise may occur if proper grounding is not applied.
3) Additional load may be needed on outputs VAROUTR and VAROUTL to
obtain the full range of volume control. Apply a 10-k
Ω
load on VAROUTR