LT1494 datasheet(16/22 Pages) LINER

16 / 22 page

LT6016/LT6017

60167fa

Distortion

There are two main contributors of distortion in op amps:

output crossover distortion as the output transitions

from sourcing to sinking current and distortion caused

by nonlinear common mode rejection. If the op amp is

operating in an inverting configuration there is no com-

mon mode induced distortion. If the op amp is operating

in the noninverting configuration within the normal input

common mode range (V– to V+ –1.5V) the CMRR is very

good, typically over 120dB. When the LT6016 transitions

input stages going from the normal input stage to the

Over-The-Top input stage or vice-versa, there will be a

significant degradation in linearity due to the change in

input circuitry.

Lower load resistance increases distortion due to a net

decrease in loop gain, and greater voltage swings internal

to the amp necessary to drive the load, but has no effect

on the input stage transition distortion. The lowest distor-

tion can be achieved with the LT6016/LT6017 sourcing in

class-A operation in an inverting configuration, with the

input common mode biased mid-way between the supplies.

Power Dissipation Considerations

Because of the ability of the LT6016/LT6017 to operate on

power supplies up to ±25V and to drive heavy loads, there

is a need to ensure the die junction temperature does not

exceed 150°C. The LT6016 is housed in an 8-lead MSOP

package (θJA = 273°C/W). The LT6017 is housed in a 22

pin leadless DFN package (DJC22, θJA = 31.8°C/W).

In general, the die junction temperature (TJ) can be esti-

mated from the ambient temperature TA, and the device

power dissipation PD:

TJ = TA + PD • θJA

The power dissipation in the IC is a function of supply

voltage and load resistance. For a given supply voltage,

the worst-case power dissipation PD(MAX) occurs at the

maximum supply current with the output voltage at half

of either supply voltage (or the maximum swing is less

than one-half the supply voltage). PD(MAX) is given by:

PD(MAX) = (VS • IS(MAX)) + (VS/2)2/RLOAD

Example: An LT6016 in a MSOP package mounted on a PC

board has a thermal resistance of 273°C/W. Operating on

±25V supplies with both amplifiers simultaneously driving

2.5kΩ loads, the worst-case IC power dissipation for the

given load occurs when driving 12.5VPEAK and is given by:

PD(MAX) = 2 • 50 • 0.6mA + 2 • (12.5)2/2500 = 0.185W

With a thermal resistance of 273°C/W, the die temperature

will experience approximately a 50°C rise above ambient.

This implies the maximum ambient temperate the LT6016

should ever operate under the assumed conditions:

TA = 150°C – 50°C = 100°C

To operate to higher ambient temperatures, use two chan-

nels of the LT6017 quad which has lower thermal resistance

θJA=31.8°C/W,andanexposedpadwhichmaybesoldered

down to a copper plane (connected to V–) to further lower

the thermal resistance below θJA = 31.8°C/W.

APPLICATIONS INFORMATION

LT1494 Datasheet(PDF) 16 Page - Linear Technology

LT1494 Datasheet(HTML) 16 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Datasheet Descarga

Enlace URL