MAX9776ETJ+ Maxim Integrated Products, MAX9776ETJ+ Datasheet - Page 19
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MAX9776ETJ+
Manufacturer Part Number
MAX9776ETJ+
Description
IC AMP AUDIO PWR 1.5W D 32TQFN
Manufacturer
Maxim Integrated Products
Series
DirectDrive™r
Type
Class Dr
Datasheet
1.MAX9776ETJ.pdf
(38 pages)
Specifications of MAX9776ETJ+
Output Type
1-Channel (Mono) with Stereo Headphones
Max Output Power X Channels @ Load
1.5W x 1 @ 4 Ohm; 60mW x 2 @ 16 Ohm
Voltage - Supply
2.7 V ~ 5.5 V
Features
Depop, Differential Inputs, I²C, Mute, Short-Circuit and Thermal Protection, Shutdown, Volume Control
Mounting Type
Surface Mount
Package / Case
32-TQFN Exposed Pad
Product
Class-D
Output Power
1.5 W
Common Mode Rejection Ratio (min)
45 dB
Thd Plus Noise
0.04 %
Operating Supply Voltage
2.7 V to 5.5 V
Supply Current
9.5 mA
Maximum Power Dissipation
1360 mW
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Supply Voltage (max)
5.5 V
Supply Voltage (min)
2.7 V
Amplifier Class
D
No. Of Channels
3
Supply Voltage Range
2.7V To 5.5V
Load Impedance
4ohm
Operating Temperature Range
-40°C To +85°C
Amplifier Case Style
TQFN
Rohs Compliant
Yes
For Use With
MAX9776EVKIT+ - EVALUATION KIT FOR MAX9776
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX9775/MAX9776 ultra-low-EMI, filterless, Class D
audio power amplifiers feature several improvements to
switch-mode amplifier technology. The MAX9775/
MAX9776 feature active emissions limiting circuitry to
reduce EMI. Zero dead-time technology maintains state-
of-the-art efficiency and THD+N performance by allowing
the output FETs to switch simultaneously without cross-
conduction. A unique filterless modulation scheme and
spread-spectrum modulation create compact, flexible,
low-noise, efficient audio power amplifiers while
occupying minimal board space. The differential input
architecture reduces common-mode noise pickup with or
without the use of input-coupling capacitors. The
MAX9775/MAX9776 can also be configured as single-
ended input amplifiers without performance degradation.
The MAX9775/MAX9776 feature three fully differential
input pairs (INA_, INB_, INC_) that can be configured
as stereo single-ended or mono differential inputs. I
provides control for input configuration, volume level,
and mixer configuration. The MAX9775’s 3D enhance-
ment feature widens the stereo sound field to improve
stereo imaging when stereo speakers are placed in
close proximity.
Figure 1. Outputs with an Input Signal Applied
V
V
V
IN+
OUT+
IN-
2 x 1.5W, Stereo Class D Audio Subsystem
- V
OUT-
OUT+
OUT-
______________________________________________________________________________________
Detailed Description
with DirectDrive Headphone Amplifier
t
ON(MIN)
t
SW
2
C
DirectDrive allows the headphone and mono receiver
amplifiers to output ground-referenced signals from a
single supply, eliminating the need for large DC-block-
ing capacitors. Comprehensive click-and-pop suppres-
sion minimizes audible transients during the turn-on
and turn-off of amplifiers.
Comparators monitor the audio inputs and compare the
complementary input voltages to a sawtooth waveform.
The comparators trip when the input magnitude of the
sawtooth exceeds their corresponding input voltage. The
active emissions limiting circuitry slightly reduces the
turn-on rate of the output H-bridge by slew-rate limiting
the comparator output pulse. Both comparators reset at
a fixed time after the rising edge of the second compara-
tor trip point, generating a minimum-width pulse
(t
parator (Figure 1). As the input voltage increases or
decreases, the duration of the pulse at one output
increases while the other output pulse duration remains
the same. This causes the net voltage across the speak-
er (V
helps the devices to achieve high levels of linearity.
ON(MIN)
OUT+
,100ns typ) at the output of the second com-
- V
OUT-
) to change. The minimum-width pulse
Class D Speaker Amplifier
19