MAX9752 datasheet(20/29 Pages) MAXIM

20 / 29 page

Beep Input (MAX9752)

The MAX9752 features an audible alert beep input

(BEEP). BEEP serves as the alert signal detector and the

alert input to the amplifiers. AC-couple the alert output of

a µC to BEEP. The MAX9752 monitors the signal at

BEEP. When a signal exceeding 400mVP-P with a fre-

quency greater than 300Hz is detected at BEEP, the

MAX9752 connects the signal to the amplifiers after eight

periods of the input signal. In speaker mode, the alert

signal appears at both speaker outputs, mixed with any

audio that may be present. In headphone mode, the alert

signal appears at the headphone outputs, mixed with

any audio that may be present. A signal with less than

eight input periods is ignored. Multiple BEEP signals can

be summed as shown in Figure 11. Adding external

resistors in series with BEEP increase the minimum volt-

age amplitude sensitivity.

Input Mux (MAX9753)

The MAX9753 features a 2:1 input multiplexer on each

amplifier, allowing input selection between two stereo

sources. The logic input IN1/2 controls both multiplexers.

A logic-high selects input IN_1 and a logic-low selects

input IN_2. The unselected inputs are high impedance.

Shutdown

The MAX9752/MAX9753/MAX9754 feature an 8µA, low-

power shutdown mode reducing quiescent current con-

sumption and extending battery life. Driving SHDN low

disables the drive amplifiers, bias circuitry, charge

pump, and sets the headphone amplifier output imped-

ance to 1k

Ω, and drives BIAS to GND. Connect SHDN to

VDD for normal operation.

2.2W, Low-EMI, Stereo, Class D Power Amplifiers

with DirectDrive Headphone Amplifiers

______________________________________________________________________________________

MAX9752

VREF

DAC

HPVDD

VOL

Figure 9. MAX9752 Volume-Control Circuit

-80

-60

-70

-40

-50

-20

-30

-10

1.0

1.5

0.5

2.0

2.5

3.0

3.5

4.0

MAX9752B

VOLUME-CONTROL TRANSFER FUNCTION

VVOL (V)

AUDIO

TAPER POT

GAIN1 = GAIN2 = 0

SPEAKER MODE

HEADPHONE MODE

Figure 10b. MAX9752B Volume-Control Transfer Functions

-80

-60

-70

-40

-50

-20

-30

-10

1.0

1.5

0.5

2.0

2.5

3.0

3.5

4.0

MAX9752A

VOLUME-CONTROL TRANSFER FUNCTION

VVOL (V)

AUDIO

TAPER POT

GAIN1 = GAIN2 = 0

SPEAKER MODE

HEADPHONE MODE

Figure 10a. MAX9752A Volume-Control Transfer Functions

-80

-60

-70

-40

-50

-20

-30

-10

1.0

1.5

0.5

2.0

2.5

3.0

3.5

4.0

MAX9752C

VOLUME-CONTROL TRANSFER FUNCTION

VVOL (V)

AUDIO

TAPER POT

GAIN1 = GAIN2 = 0

SPEAKER MODE

HEADPHONE MODE

Figure 10c. MAX9752C Volume-Control Transfer Functions

MAX9752 Datasheet(PDF) 20 Page - Maxim Integrated Products

MAX9752 Datasheet(HTML) 20 Page - Maxim Integrated Products

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

Datasheet Download

Link URL