max9761 Maxim Integrated Products, Inc., max9761 Datasheet - Page 14

• Manufacturer Part Number: max9761
• Description: Stereo 3w Audio Power Amplifiers With Headphone Drive And Input Mux
• Manufacturer: Maxim Integrated Products, Inc.

Stereo 3W Audio Power Amplifiers with
Headphone Drive and Input Mux
GND. Driving SHDN low places the devices into shut-
down mode, disables the interface, and resets the I
registers to a default state. A logic high on SHDN
enables the devices.
A logic high on bit 0 of the SHDN register places the
MAX9760/MAX9762 in shutdown mode. A logic low
enables the device. The digital section of the
MAX9760/MAX9762 remains active when the device is
shut down through the interface. All devices feature a
logic low on the SHDN input.
All devices feature a mute mode. When the device is
muted, the input is disconnected from the amplifiers.
MUTE does not shut down the device.
The MAX9760/MAX9762 MUTE mode is selected by
writing to the MUTE register (see the Command Byte
Definitions section). The left and right channels can be
independently muted.
The MAX9761/MAX9763 feature an active-high MUTE
input that mutes both channels.
The MAX9760–MAX9763 feature Maxim’s patented
comprehensive click-and-pop suppression. During
startup and shutdown, the common-mode bias voltage
of the amplifiers is slowly ramped to and from the DC
bias point using an S-shaped waveform. In headphone
mode, this waveform shapes the frequency spectrum,
minimizing the amount of audible components present
at the headphone. In speaker mode, the BTL amplifiers
start up in the same fashion as in headphone mode.
When entering shutdown, both amplifier outputs ramp
to GND quickly and simultaneously. The MAX9760–
MAX9763 can also be connected to a standby power
source that ensures that the device undergoes its full
shutdown cycle even after power has been removed.
The MAX9760–MAX9763 feature a patented system
that provides clickless power-down when power is
inadvertently removed from the device. SV
optional secondary supply that powers the device
through its shutdown cycle when V
During this cycle, the amplifier output DC level slowly
ramps to GND, ensuring clickless power-down. If click-
less power-down is required, connect SV
secondary power supply that is always on, or connect a
reservoir capacitor from SV
14
______________________________________________________________________________________
MAX9760/MAX9762 Software Shutdown
Click-and-Pop Suppression
Standby Power Supply (SV
DD
MAX9760/MAX9762 MUTE
MAX9761/MAX9763 MUTE
to GND. SV
DD
DD
is removed.
DD
to either a
DD
does not
MUTE
is an
DD
2
C
)
need to be connected to either a secondary power
supply or reservoir capacitor for normal device opera-
tion. If click-and-pop suppression during power-down
is not required, connect SV
Figure 2. HPS Configuration Circuit
Table 1a. HPS Setting (MAX9760/MAX9761)
*Note:
A – GAINA path selected
B – GAINB path selected
M – GAINM path selected
A or B – Gain path selected by GAINAB control bit in register
02h
Table 1b. HPS Setting (MAX9762/MAX9763)
*Note:
A or B – Gain path selected by external GAINAB
M – GAINM path selected
HPSD
HPSEN
0
0
1
1
0
1
1
INPUTS
HPS
INPUTS
X
X
0
1
HPS
MAX9760–
MAX9763
X
0
1
OUTL+
OUTR+
SPKR/HP
HPS
MODE
X
X
0
1
BTL
BTL
SE
47kΩ
10kΩ
R3
DD
MODE
GAIN PATH*
R2
BTL
BTL
MAX9761
SE
SE
to V
A or B
A or B
A or B
V
DD
DD
MAX9760
R1
680kΩ
PATH*
A or B
A or B
GAIN
directly.
A
B
GAIN PATH*
MAX9763
A or B
MAX9762
PATH*
M
M
A or B
GAIN
M
M
B