MAX4230 Ver la hoja de datos (PDF) - Maxim Integrated

Número de pieza

componentes Descripción

Fabricante

MAX4230

High-Output-Drive, 10MHz, 10V/µs, Rail-to-Rail I/O Op Amps with Shutdown in SC70

Maxim Integrated 

High-Output-Drive, 10MHz, 10V/µs,

Rail-to-Rail I/O Op Amps with Shutdown in SC70

3.6V

R

C

VIN = 2VP-P

R

MAX4230

MAX4231

32Ω

Figure 1. MAX4230/MAX4231 Used in Single-Supply Operation

Circuit Example

CIN

RIN

LEFT

AUDIO INPUT

VBIAS

RF

COUT

MAX4230

HEADPHONE JACK

TO 32Ω STEREO

HEADSET

CIN

RIN

RIGHT

AUDIO INPUT

COUT

RF

Figure 2. Circuit Example: Adding a Coupling Capacitor

Greatly Reduces Power Dissipation of its Package

For example, the circuit in Figure 1 has a package

power dissipation of 196mW:

( ) RMS ≅ VDD − VDC + VPEAK

2

= 3.6V − 1.8V + 1.0V = 2.507VRMS

2

IRMS ≅ IDC + IPEAK

2

= 1.8V + 1.0V / 32Ω

32Ω

2

= 78.4mARMS

where:

VDC = the DC component of the output voltage.

IDC = the DC component of the output current.

VPEAK = the highest positive excursion of the AC com-

ponent of the output voltage.

IPEAK = the highest positive excursion of the AC com-

ponent of the output current.

Therefore:

PIC(DISS) = VRMS IRMS COS θ

= 196mW

Adding a coupling capacitor improves the package

power dissipation because there is no DC current to the

load, as shown in Figure 2:

VRMS ≅ VPEAK

2

= 1.0V = 0.707VRMS

2

IRMS ≅ IDC + IPEAK = 0A + 1.0V / 32Ω

2

2

= 22.1mARMS

Therefore:

PIC(DISS) = VRMS IRMS COS θ

= 15.6mW

If the configuration in Figure 1 were used with all four of

the MAX4234 amplifiers, the absolute maximum power-

dissipation rating of this package would be exceeded

(see the Absolute Maximum Ratings section).

60mW Single-Supply Stereo

Headphone Driver

Two MAX4230/MAX4231s can be used as a single-sup-

ply, stereo headphone driver. The circuit shown in

Figure 2 can deliver 60mW per channel with 1% distor-

tion from a single 5V supply.

The input capacitor (CIN), in conjunction with RIN, forms

a highpass filter that removes the DC bias from the

incoming signal. The -3dB point of the highpass filter is

given by:

f

−3dB

=

1

2πRINCIN

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