max97220a Maxim Integrated Products, Inc., max97220a Datasheet - Page 14

• Manufacturer Part Number: max97220a
• Description: Differential Input Directdrive Line Drivers/headphone Amplifiers
• Manufacturer: Maxim Integrated Products, Inc.

Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
The MAX97220_ is compatible with the footprint of the
MAX9722. BIAS on the MAX97220_ is in the same posi-
tion as SVSS. On the MAX9722, SVSS is connected to
PVSS. For the MAX97220_, there is only one charge-
pump output that doubles as the amplifier’s negative
power-supply input. The connection of negative charge-
pump output and amplifier negative power-supply input
is internal on the MAX97220_ and external on the
MAX9722.
To implement a PCB that is compatible with both the MAX9722
and MAX97220_, put a capacitor pad from BIAS/SVSS
(MAX97220_/MAX9722 pin 11) to PGND. Also, place a 0I
resistor pad from BIAS/SVSS (MAX97220_/MAX9722 pin
11) to PVSS (pin 5 on both parts). Install the 0I resistor
when the MAX9722 is used and leave the resistor out of
circuit when the MAX97220_ is used (Figure 4).
While driving a headphone load, the IC dissipates a sig-
nificant amount of power. The maximum power dissipa-
tion is given in the Continuous Power Dissipation of the
Absolute Maximum Ratings section or can be calculated
by the following equation:
Figure 4. MAX97220A vs. MAX9722 PCB Layout
14
0.47µF
0.47µF
0.47µF
0.47µF
10kI
10kI
10kI
10kI
10kI
10kI
Applications Information
+INL
+INR
-INR
-INL
MAX97220A
10kI
10kI
1µF
SHDN
MAX9722 Compatibility
2.5V TO 5.5V
CHARGE
PUMP
PVDD SVDD
SGND PGND
Power Dissipation
OUTL
BIAS
C1P
C1N
PVSS
OUTR
1µF
C1
1µF
0.1µF
1µF
C2
OPEN
where T
and B
as specified in the Absolute Maximum Ratings section.
Since the IC is a stereo amplifier, the total maximum
internal power dissipation for a given V
given by the following equation:
If the internal power dissipation for a given application
exceeds the maximum allowed for a given package,
reduce power dissipation by decreasing supply voltage,
ambient temperature, input signal, or gain, or by increasing
load impedance.
The TQFN package features an exposed thermal pad
on its underside. This pad lowers the package's thermal
impedance by providing a direct heat conduction path
from the die to the PCB. Connect the exposed thermal
pad to PGND or an isolated plane.
0.47µF
0.47µF
0.47µF
0.47µF
JA
10kI
10kI
10kI
10kI
J(MAX)
is the reciprocal of the derating factor in NC/W
10kI
10kI
is +150NC, T
P
+INR
+INL
-INR
-INL
D(MAX)
P
D(MAX)
MAX9722
10kI
10kI
1µF
SHDN
=
T
A
=
2.5V TO 5.5V
J(MAX)
is the ambient temperature,
4V
π
CHARGE
q
PUMP
2 L
PVDD SVDD
SGND PGND
JA
DD
R
−
2
T
A
OUTL
SVSS
C1P
C1N
PVSS
OUTR
1µF
C1
DD
and load is
1µF
1µF
1µF
0I