Datasheet

Stereo, High-Power, Class D Amplifiers
MAX98400A/MAX98400B
15
Mono Configuration for MAX98400A
Detailed Description
The MAX98400A/MAX98400B Class D amplifiers pro-
vide high-performance, thermally efficient amplifier solu-
tions. The MAX98400A delivers 2x20W into 8I loads or
1x40W into a 4I load. The MAX98400B delivers 2x12W
into 8I loads.
An integrated limiting circuit prevents output clipping
distortion and protects small speakers from transient
voltages.
A thermal-foldback feature can be enabled to automati-
cally reduce the output power if the supply voltage, input
signal, and/or ambient temperature are too high to oper-
ate within a junction temperature of +130NC. Traditional
thermal protection is also available in addition to robust
overcurrent protection.
Both devices operate from an 8V to 28V supply and pro-
vide a high 67dB PSRR, eliminating the need for a regu-
lated power supply. They offers up to 90% efficiency
from a 12V supply.
Filterless modulation allows the ICs to pass EN55022B
EMI limits with 1m cables using only a low-cost fer-
rite bead and small-value capacitor on each output
(Figure 1).
Comprehensive click-and-pop reduction circuitry mini-
mizes noise coming into and out of shutdown.
MAX98400A
INL+
OUTL+
OUTL-
OUTR+
OUTR-
11
MONO
13
4, 5
1, 2
23, 24
26, 27
INL-
TEMPLOCK
12
19
PGA
CLIPPING
LIMITER
REGULATOR
THERMAL
FOLDBACK
INR+ 17
INR- 16
PGA
CLIPPING
LIMITER
LIMITER
CONTROL
GAIN
SELECTION
BIAS AND
OSCILLATOR
LIM_TH
10
6
V
S
V
S
RELEASE
20
31, 32, 33
PVDD
G1
8
G2
9
SHDN
ENABLE
21
GND
14, 15
PGND
29, 30,
34, 35
POWER
STAGE
WITH THERMAL
AND
OVERCURRENT
PROTECTION
C
2
1.0µF
C
1
1.0µF
C
BULK
200µF
C
REL
1.0µF
C
IN
1µF
C
IN
1µF
C
IN
1µF
C
IN
1µ
F
8V TO 28V
LEFT
INPUT
RIGHT
INPUT