Datasheet

For example, the circuit in Figure 1 has a package power
dissipation of 196mW:
PEAK
DD DC
RMS
PEAK
RMS DC
RMS
V
RMS (V V )
2
1.0V
3.6V 1.8V 2.507V
2
I
1.8V 1.0V / 32
II
32
22
78.4mA
≅−+
= −+ =
Ω
≅+ = +
Ω
=
where:
V
DC
= the DC component of the output voltage.
I
DC
= the DC component of the output current.
V
PEAK
= the highest positive excursion of the AC compo-
nent of the output voltage.
I
PEAK
= the highest positive excursion of the AC compo-
nent of the output current.
Therefore:
IC(DISS) RMS RMS
P = V I COS
= 196mW
θ
Adding a coupling capacitor improves the package power
dissipation because there is no DC current to the load, as
shown in Figure 2:
PEAK
RMS
RMS
PEAK
RMS DC
RMS
V
V
2
1.0V
0.707V
2
I
1.0V / 32
I I 0A
22
22.1mA
≅
= =
Ω
≅+ =+
=
Therefore:
IC(DISS) RMS RMS
P = V I COS
= 15.6mW
θ
If the configuration in Figure 1 were used with all four of
the MAX4234 amplifiers, the absolute maximum power
dissipation rating of this package would be exceeded (see
the Absolute Maximum Ratings section).
60mW Single-Supply Stereo
Headphone Driver
Two MAX4230/MAX4231s can be used as a single-supply,
stereo headphone driver. The circuit shown in Figure 2 can
deliver 60mW per channel with 1% distortion from a single
5V supply.
The input capacitor (C
IN
), in conjunction with R
IN
, forms a
highpass filter that removes the DC bias from the incom-
ing signal. The -3dB point of the highpass filter is given by
3dB
IN IN
1
f
2R C
−
=
π
Figure 1. MAX4230/MAX4231 Used in Single-Supply Operation
Circuit Example
Figure 2. Circuit Example: Adding a Coupling Capacitor Greatly
Reduces Power Dissipation of its Package
3.6V
V
IN
= 2V
P-P
R
C
32Ω
R
MAX4230
MAX4231
RIGHT
AUDIO INPUT
LEFT
AUDIO INPUT
C
IN
C
IN
R
IN
R
IN
R
F
C
OUT
V
BIAS
HEADPHONE JACK
TO 32Ω STEREO
HEADSET
R
F
MAX4230
C
OUT
MAX4230–MAX4234 High-Output-Drive, 10MHz, 10V/μs,
Rail-to-Rail I/O Op Amps with Shutdown in SC70
www.maximintegrated.com
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