MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER

MP7770 Rev.1.0

www.MonolithicPower.com

15

12/4/2012

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© 2012 MPS. All Rights Reserved.

Enable Function

The MP7770 EN input is an active-high–enable

control. To enable the MP7770, drive EN with a

voltage 2.0V or higher; to disable the amplifier,

drive it below 0.4V. While the MP7770 is

disabled, the VDD operating current is around

250μA and the output driver MOSFETs are

turned off.

Programmable UVP

MP7770 integrate programmable UVP function,

which can be used to shutdown the MP7770 to

escape the pop, by controlling the UVP node

voltage. The VDD shutdown voltage can be

flexibly adjusted by the external resistor, as

shown in the figure 3.

VDD

UVP

AGND

+2.2V

+

-

Figure 3: UVP Block Diagram

the VDD shutdown voltage (rising threshold)

can be calculated by the equation:

HL

VDD _ shutdown

L

(R

R )

V2.2 *

R





If the UVP pin is NC, the default VDD shutdown

voltage (rising threshold) is 8.4V since there is

internal voltage divided circuit.

For example, please see the table 1 for

recommended UVP setting for reduce the

power off pop.

Table 1

VDD

(V)

VDD_shutdown

(V)

12

8.6

15k

5.1k

24

19

39k

5.1k

36

26

56k

5.1k

Thermal Information

The MP7770 is available in a thermally-

enhanced TSSOP28 package. The user can

choose between two package options, with the

exposed pad on top or bottom.

The

thermally-augmented

TSSOP-EPR

package with the exposed pad on top is

designed to interface directly with heat sinks

using a thermal interface compound. The heat

sink then absorbs heat from the ICs and

couples it to the local air. If louvers or fans are

used, this process can reach equilibrium and

heat can be continually removed from the ICs.

Because of the efficiency of the MP7770, heat

sinks can be smaller than those required for

linear amplifiers.

The TSSOP28-EPR is not intended for use

without a heatsink. For cases without a heatsink,

please use the TSSOP28-EP with the exposed

pad on the bottom.