Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsLinear IC - Audio amplifier Headphones (2-channel, stereo) Class AB TQFN 16 EP (3x3)

14 Maxim Integrated

Differential Input DirectDrive

Line Drivers/Headphone Amplifiers

MAX97220A–MAX97220E

Applications Information

MAX9722 Compatibility

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).

Power Dissipation

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:

J(MAX) A

D(MAX)

−

where T

J(MAX)

is +150NC, T

is the ambient temperature,

and B

is the reciprocal of the derating factor in NC/W

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

and load is

given by the following equation:

D(MAX)

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.

Figure 4. MAX97220A vs. MAX9722 PCB Layout

0.47µF

10kI

SHDN

-INR

+INR

+INL

-INL

OUTL

BIAS

C1P

CHARGE

PUMP

C1N

PVSS

1µF

OPEN

0.1µF

1µF

OUTR

SGND PGND

PVDD SVDD

1µF

2.5V TO 5.5V

MAX97220A