KK34119
A 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 Electrical
Characteristics as R
FC1
and R
FC2
).
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 KΩ and 125 KΩ resistors.
and load power.The maximum power which can safely
be dissipated within the
KK34119
is found from the
following equation:
P
D
= (140°C - T
A
)/θ
JA
where T
A
is the operating temperature;
and
θ
JA
is the package thermal resistance (100°C/W for
the standard DIP package, and 180°C/W for the surface
mount package).
The power dissipated within the
KK34119,
in a given
application, is found from the following eguation:
P
D
= (V
CC
x I
CC
) + (I
RMS
x V
CC
) - (R
L
x I
RMS2
).
where I
CC
is obtained from Figure 1;
and I
RMS
is the RMS current at the load;
and R
L
is the load resistance.
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
KK34119.
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
KK34119.
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.
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
KK34119
is enabled
for normal operation. When Pin 1 is at a Logic “1” (2.0
to V
CC
Volts), the IC is 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 KΩ. 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 independent of C1, C2, and
V
CC
.
When the
KK34119
is disabled, the voltages at FC1
and FC2 do not change as they are powered from V
CC
.
The outputs, VO1 and VO2, change to a 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 within the range
of V
CC
and Ground.
LAYOUT CONSIDERATIONS
Normally a snubber is not needed at the output of the
KK34119,
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.
POWER DISSIPATION
Figures 2-4 indicate the device dissipation (within
the IC) for various combinations of V
CC
, R
L
,
MAXIMUM RATINGS
*
Symbol
V
CC
I
OUT
V
IN
V
VO
Tstg
*
Parameter
Supply Voltage
Maximum Output Current at VO1, VO2
MaximumInput Voltage(FC1, FC2, CD, V
IN
)
Applied Output Voltage to VO1, VO2 when disabled
Storage Temperature Range
Value
1.0 to +18
±250
-1.0 toV
CC
+1.0
-1.0 toV
CC
+1.0
-65 to +150
Unit
V
mA
V
V
°C
Maximum Ratings are those values beyond which damage to the device may occur.
Functional operation should be restricted to the Recommended Operating Conditions.
3
KODENSHI [ KODENSHI KOREA CORP. ]
