IL34119

3

line powered speakerphone, for example, will require

more filtering than a circuit powered by a well

requlated power supply. The amount of rejection is a

function of the capacitors, and the equivalent

impedance looking into FC1 and FC2 (listed in the

In addition to providing filtering, C1 and C2 also

affect the turn-on time of the circuit at power-up,

since the two capacitors must change up through the

internal 50 K

Ω and 125 KΩ resistors.

CHIP DISABLE

The Chip Disable (Pin 1) can be used to power

down the IC to conserve power, or for muting, or

both. When at a Logic “0” (0 to 0.8 Volts), the

IL34119 is enabled for normal operation. When Pin 1

disabled. If Pin 1 is open, that is equivalent to a Logic

“0”, although good design practice dictates that an

input should never be left open. Input impedance at

Pin 1 is a nominal 90 K

Ω. The power supply current

(when disabled) is shown in Figure 1.

Muting, defined as the change in differential gain

from normal operation to muted operation, is in

excess of 70 dB. The turn-off time of the audio

output, from the application of the CD signal, is

<2.0

µs, and turn on-time is 12-15 ms. Both times are

When the IL34119 is disabled, the voltages at

FC1 and FC2 do not change as they are powered

high impedance condition, removing the signal from

the speaker. If signals from other sources are to be

applied to the outputs (while disabled), they must be

POWER DISSIPATION

Figures 2-4 indicate the device dissipation (within

and load power.The maximum power which can

safely be dissipated within the IL34119 is found from

the following equation:

and

θ

for the standard DIP package, and 180

°C/W for the

surface mount package).

The power dissipated within the IL34119, in a

given application, is found from the following

eguation:

Figures 2-4, along with Figures 5-7 (distortion

curves), and a peak working load current of

±200 mA, define the operating range for the

IL34119. The operating range is further defined in

terms of allowable load power in Figure 8 for load of

8.0

Ω, 16 Ω, and 32 Ω. The left (ascending) portion

of each of the three curves is defined by the power

level at which 10% distortion occurs. The center flat

portion of each curve is defined by the maximum

output current capability of the IL34119. The right

(descending) portion of each curve is defined by the

maximum internal power dissipation of the IC at

25

°C. At higher operating be reduced according to

the above equations. Operating the device beyond the

current and junction temperature limits will degrade

long term reliability.

LAYOUT CONSIDERATIONS

Normally a snubber is not needed at the output of

the IL34119, unlike many other audio amplifiers.

However, the PC board layout, stray capacitances,

and the manner in which the speaker wires are

configured, may dictate otherwise. Generally the

speaker wires should be twisted tightly, and be not

more than a few inches in length.

MAXIMUM RATINGS

*

Symbol

Parameter

Value

Unit

Supply Voltage

1.0 to +18

V

Maximum Output Current at VO1, VO2

±250

mA

V

Applied Output Voltage to VO1, VO2 when disabled

V

Tstg

Storage Temperature Range

-65 to +150

°C

Functional operation should be restricted to the Recommended Operating Conditions.