High-Output-Drive, Precision, Low-Power, Single-

Supply, Rail-to-Rail I/O Op Amps with Shutdown

_______________________________________________________________________________________

9

Applications Information

Package Power Dissipation

Warning: Due to the high output current drive, this op

amp can exceed the absolute maximum power-dissi-

pation rating. As a general rule, as long as the peak cur-

rent is less than or equal to 80mA, the maximum package

power dissipation will not be exceeded for any of the

package types offered. There are some exceptions to this

rule, however. The absolute maximum power-dissipation

rating of each package should always be verified using

the following equations. The following equation gives an

approximation of the package power dissipation:

when sourcing current

when sinking current

the op amp and the load

θ = the phase difference between the

voltage and the current. For resistive

loads, COS

θ = 1.

For example, the circuit in Figure 1 has a package

power dissipation of 157mW.

θ

= 157mW

Adding a coupling capacitor improves the package

power dissipation because there is no DC current to

the load, as shown in Figure 2.

θ

= 38.6mW

The absolute maximum power-dissipation rating of this

package would be exceeded if the configuration in

Figure 1 were used with all four of the MAX4169ESD’s

amplifiers at a high ambient temperature of +75°C

(157mW x 4 amplifiers = 628mW + a derating of

8.33mW/°C x 5°C = 669mW). Note that 669mW just

exceeds the absolute maximum power dissipation of

667mW for the 14-pin SO package (see the

Absolute

Maximum Ratings section).

V

V

V

I

+

I

2

RMS

CC

DC

RMS

PEAK

≅

−

(

=

−

−

=

≅

=

+

=

.

.

.

.

.

/

.

V

V

V

V

V

I

A

V

mA

PEAK

RMS

DC

RMS

2

6 5

3 25

1 5

2

2 189

0

1 5

60

2

17 67

Ω

V

V

V

I

+

I

2

RMS

CC

DC

RMS

PEAK

≅

−

(

=

−

−

=

≅

=

+

=

.

.

.

.

.

.

/

.

V

V

V

V

V

I

V

V

mA

PEAK

RMS

DC

RMS

2

6 5

3 25

1 5

2

2 189

3 25

60

1 5

60

2

71 84

Ω

Ω

P

V

I

COS

IC DISS

RMS RMS

(

θ

6.5V

R

C

60

Ω

R

MAX4165

MAX4166

Figure 1. A Circuit Example where the MAX4165/MAX4166 is

Being Used in Single-Supply Operation

6.5V

R

60

Ω

R

C

1

2

MAX4165

MAX4166

Figure 2. A Circuit Example where Adding a Coupling

Capacitor Greatly Reduces the Power Dissipation of Its

Package