Output Power vs Supply Voltage

Chs 1&3 in Bridge Mode (Note15),

f = 1kHz, R

Ω, 80kHz BW

Output Power vs Supply Voltage

Chs 1&3 in Parallel Mode (Note16),

f = 1kHz, R

Ω, 80kHz BW

20079413

20079415

Output Power vs Supply Voltage

All Chs in Parallel Mode (Note16),

f = 1kHz, R

Ω, 80kHz BW

20079414

Note 15: Bridge mode graphs were taken using the demo board and inverting the signal to the channel B input.

Note 16: Parallel mode graphs were taken using the demo board connecting each output through a 0.1

Ω/3W resistor to the load.

Application Information

MUTE MODE

The muting function allows the user to mute the amplifier.

This can be accomplished as shown in the Typical Applica-

tion Circuit. The resistor R

negative supply voltage and is used in conjunction with a

switch. The switch, when opened or switched to GND, cuts

off the current flow from the MUTE pins to −V

the LM4733 into mute mode. Refer to the Mute Attenuation

vs Mute Current curves in the Typical Performance Char-

acteristics section for values of attenuation per current out

of each MUTE pin. The resistance R

following equation:

R

M

≤ (|−V

Where I

MUTE

≥ 0.5mA for each MUTE pin.

The MUTE pins can be tied together so that only one resistor

is required for the mute function. The mute resistor value

must be chosen so that a minimum of 1.5mA is pulled

through the resistor R

fully operational. Taking into account supply line fluctuations,

it is a good idea to pull out 1mA per MUTE pin or 3mA total

if all pins are tied together.

A turn-on MUTE or soft start circuit may also be used during

power up. A simple circuit like the one shown below may be

used.

200794B7

The RC combination of C

at point A to change more slowly than the -V

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