MAX97001EWP+ MAXIM [Maxim Integrated Products], MAX97001EWP+ Datasheet - Page 18

• Manufacturer Part Number: MAX97001EWP+
• Description: Audio Subsystem with Mono Class D Speaker and Class H Headphone Amplifiers
• Manufacturer: MAXIM [Maxim Integrated Products]

Figure 2. Signal Path
Audio Subsystem with Mono Class D Speaker
and Class H Headphone Amplifiers
The MAX97001 mono audio subsystem combines a
mono speaker amplifier with a stereo headphone ampli-
fier and an analog DPST switch. The high-efficiency,
700mW, Class D speaker amplifier operates directly
from the battery and consumes no more than 1FA when
in shutdown mode. The headphone amplifier utilizes a
dual-mode charge pump and a Class H output stage
to maximize efficiency while outputting a ground-ref-
erenced signal that does not require output-coupling
capacitors. The headphone and speaker amplifiers
have independent volume control and on/off control.
The 4 inputs are configurable as 2 differential inputs or
4 single-ended inputs. All control is performed using the
2-wire I
The speaker amplifier incorporates a distortion limiter to
automatically reduce the volume level when excessive
clipping occurs. This allows high gain for low-level sig-
nals without compromising the quality of large signals.
The MAX97001 signal path consists of flexible inputs,
signal mixing, volume control, and output amplifiers
18
2
C interface.
INA2
INA1
INB2
INB1
Detailed Description
-6dB TO +18dB
-6dB TO +18dB
INPUT A
INPUT B
Signal Path
MIXER
MUX
AND
(Figure 2). The inputs can be configured for single-
ended or differential signals (Figure 3). The internal
preamplifiers feature programmable gain settings using
internal resistors and an external gain setting using a
trimmed internal feedback resistor. The external option
allows any desired gain to be selected. Following pre-
amplification, the input signals are mixed, volume adjust-
ed, and routed to the headphone and speaker amplifiers
based on the desired configuration.
The MAX97001 features independent mixers for the left
headphone, right headphone, and speaker paths. Each
output can select any combination of any inputs. This
allows for mixing two audio signals together and rout-
ing independent signals to the headphone and speaker
amplifiers. If one of the inputs is not selected by either
mixer, it is automatically powered down to save power.
The MAX97001 Class D speaker amplifier utilizes active
emissions limiting and spread-spectrum modulation to
minimize the EMI radiated by the amplifier.
-30dB TO +20dB
-64dB TO +6dB
-64dB TO +6dB
+12dB
0/3dB
0/3dB
Class D Speaker Amplifier
Mixers