MAX9761EVKIT Maxim Integrated, MAX9761EVKIT Datasheet - Page 14

• Manufacturer Part Number: MAX9761EVKIT
• Description: Amplifier IC Development Tools
• Manufacturer: Maxim Integrated
• Series: MAX9760, MAX9761, MAX9762, MAX9763r

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 comprehen-
sive click-and-pop suppression. During startup and
shutdown, the common-mode bias voltage of the ampli-
fiers 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 head-
phone. In speaker mode, the BTL amplifiers start up in
the same fashion as in headphone mode. When enter-
ing 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 system that provides
clickless power-down when power is inadvertently
removed from the device. SV
ondary supply that powers the device through its shut-
down cycle when V
the amplifier output DC level slowly ramps to GND,
ensuring clickless power-down. If clickless power-down
is required, connect SV
supply that is always on, or connect a reservoir capaci-
tor from SV
14
______________________________________________________________________________________
DD
MAX9760/MAX9762 Software Shutdown
to GND. SV
DD
Click-and-Pop Suppression
Standby Power Supply (SV
DD
is removed. During this cycle,
DD
to either a secondary power
MAX9760/MAX9762 MUTE
MAX9761/MAX9763 MUTE
does not need to be con-
DD
is an optional sec-
MUTE
DD
2
C
)
nected to either a secondary power supply or reservoir
capacitor for normal device operation. If click-and-pop
suppression during power-down is not required, con-
nect 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
DD
HPS
INPUTS
X
X
0
1
HPS
MAX9760–
MAX9763
to V
X
0
1
DD
OUTL+
OUTR+
SPKR/HP
HPS
MODE
directly.
X
X
0
1
BTL
BTL
SE
47kΩ
10kΩ
R3
MODE
GAIN PATH*
R2
BTL
BTL
MAX9761
SE
SE
A or B
A or B
A or B
V
DD
MAX9760
R1
680kΩ
PATH*
A or B
A or B
GAIN
A
B
GAIN PATH*
MAX9763
A or B
MAX9762
PATH*
M
M
A or B
GAIN
M
M
B