max9773etgt Maxim Integrated Products, Inc., max9773etgt Datasheet - Page 10

• Manufacturer Part Number: max9773etgt
• Description: Max9773 1.8w, Filterless, Ultra-low Emi, Stereo Class D Audio Power Amplifier
• Manufacturer: Maxim Integrated Products, Inc.

The MAX9773 ultra-low EMI, filterless, stereo Class D
audio power amplifier incorporates several improve-
ments to switch-mode amplifier topology. The MAX9773
features output-driver AEL circuitry to reduce EMI. Zero
dead time technology maintains state-of-the art efficien-
cy and THD+N performance by allowing the output FETs
to switch simultaneously without cross conduction. The
MAX9773 offers Class AB performance with Class D effi-
ciency, while occupying minimal board space. A unique,
filterless modulation scheme, synchronizable switching
frequency, and spread-spectrum switching mode create
a compact, flexible, low-noise, efficient audio power
amplifier. The differential input architecture reduces
common-mode noise pickup, and can be used without
1.8W, Filterless, Ultra-Low EMI,
Stereo Class D Audio Power Amplifier
Figure 1. MAX9773 Outputs with an Input Signal Applied
10
______________________________________________________________________________________
V
V
V
IN+
OUT+
IN-
- V
OUT-
OUT+
OUT-
Detailed Description
t
ON(MIN)
t
SW
input-coupling capacitors. The inputs can also be config-
ured to accept a single-ended input signal.
Comparators monitor the MAX9773 inputs and compare
the complementary input voltages to the sawtooth wave-
form. The comparators trip when the input magnitude of
the sawtooth exceeds their corresponding input voltage.
Both comparators reset at a fixed time after the rising
edge of the second comparator trip point, generating a
minimum-width pulse (t
ond comparator (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 speaker
(V
helps the device to achieve high levels of linearity.
OUT+
- V
OUT-
) to change. The minimum-width pulse
ON(MIN)
) at the output of the sec-