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SE/BTL
ROUT+
24
R
MUX
RHPIN
RLINEIN
5
4
6
RIN
ROUT-
2
1 k
Ω
C
O
330
µ
F
100 k
Ω
23
100 k
Ω
V
DD
Input
MUX
Control
22
HP/LINE
_
+
_
+
Bypass
_
+
Bypass
EN
_
+
Bypass
LOUT+
HP/LINE OPERATION
SHUTDOWN MODES
TPA6011A4
SLOS392A – FEBRUARY 2002 – REVISED JULY 2004
APPLICATION INFORMATION (continued)
Figure 30. TPA6011A4 Resistor Divider Network Circuit
Using a 1/8-in. (3,5 mm) stereo headphone jack, the control switch is closed when no plug is inserted. When
closed the 100-k
Ω
/1-k
Ω
divider pulls the SE/BTL input low. When a plug is inserted, the 1-k
Ω
resistor is
disconnected and the SE/BTL input is pulled high. When the input goes high, the OUT- amplifier is shut down
causing the speaker to mute (open-circuits the speaker). The OUT+ amplifier then drives through the output
capacitor (C
o
) into the headphone jack.
The HP/LINE input controls the internal input multiplexer (MUX). Refer to the block diagram in Figure 30. This
allows the device to switch between two separate stereo inputs to the amplifier. For design flexibility, the
HP/LINE control is independent of the output mode, SE or BTL, which is controlled by the aforementioned
SE/BTL pin. To allow the amplifier to switch from the LINE inputs to the HP inputs when the output switches from
BTL mode to SE mode, simply connect the SE/BTL control input to the HP/LINE input.
When this input is logic high, the RHPIN and LHPIN inputs are selected. When this terminal is logic low, the
RLINEIN and LLINEIN inputs are selected. This operation is also detailed in Table 3 and the trip levels for a logic
low (V
IL
) or logic high (V
IH
) can be found in the recommended operating conditions table.
The TPA6011A4 employs a shutdown mode of operation designed to reduce supply current (I
DD
) to the absolute
minimum level during periods of nonuse for battery-power conservation. The SHUTDOWN input terminal should
be held high during normal operation when the amplifier is in use. Pulling SHUTDOWN low causes the outputs to
mute and the amplifier to enter a low-current state, I
DD
= 20 µA. SHUTDOWN should never be left unconnected
because amplifier operation would be unpredictable.
18
