MC34119DR2 Freescale Semiconductor, MC34119DR2 Datasheet - Page 4

• Manufacturer Part Number: MC34119DR2
• Description: IC AMP AUDIO LOW PWR 8-SOIC
• Manufacturer: Freescale Semiconductor
• Type: Class ABr

Specifications of MC34119DR2

• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 400mW x 1 @ 100 Ohm
• Voltage - Supply: 2 V ~ 16 V, ±1 V ~ 8 V
• Features: Shutdown
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: MC34119DTR

General
low voltage operation (V CC = 2.0 V minimum) such as that
encountered in line–powered speakerphones. The circuit
provides a differential output (V O1 –V O2 ) to the speaker to
maximize the available voltage swing at low voltages. The
differential gain is set by two external resistors. Pins FC1 and
FC2 allow controlling the amount of power supply and noise
rejection, as well as providing alternate inputs to the
amplifiers. The CD pin permits powering down the IC for
muting purposes and to conserve power.
Amplifiers
consists of two identical operational amplifiers. Amplifier #1
has an open loop gain of 80 dB (at f
closed loop gain is set by external resistor R f and R i . The
amplifier is unity gain stable, and has a unity gain frequency
of approximately 1.5 MHz. In order to adequately cover the
telephone voice band (300 Hz to 3400 Hz), a maximum
closed loop gain of 46 is recommended. Amplifier #2 is
internally set to a gain of – 1.0 (0 dB).
sinking a peak current of 200 mA. The outputs can typically
swing to within 0.4 V above ground, and to within 1.3 V
below V CC , at the maximum current. See Figures 18 and 19
for V OH and V OL curves.
function of the feedback resistor (R f ), and secondarily due to
the amplifiers’ input offset voltages. The input offset voltage
of the two amplifiers will generally be similar for a particular
IC, and therefore nearly cancel each other at the outputs.
Amplifier #1’s bias current, however, flows out of V in (Pin 4)
and through R f , forcing V O1 to shift negative by an amount
equal to [R f
The output offset voltage, specified in the Electrical
Characteristics, is measured with the feedback resistor
shown in the Typical Application Circuit, and therefore takes
into account the bias current as well as internal offset
voltages of the amplifiers. The bias current is constant with
respect to V CC .
FC1 and FC2
and C2 in the Typical Application Circuit) at FC1 and FC2. C2
is somewhat dominant at low frequencies, while C1 is
dominant at high frequencies, as shown in the graphs of
Figures 4 to 7. The required values of C1 and C2 depend on
the conditions of each application. A line powered
speakerphone, for example, will require more filtering than a
circuit powered by a well regulated 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 ).
turn–on time of the circuit at power–up, since the two
capacitors must charge up through the internal 50 k and
125 k
turn–on time upon application of V CC of +6.0 V. The turn–on
time is 60% longer for V CC = 3.0 V, and 20% less for
V CC = 9.0 V. Turn–off time is <10 s upon removal of V CC .
4
The MC34119 is a low power audio amplifier capable of
Referring to the block diagram, the internal configuration
The outputs of both amplifiers are capable of sourcing and
The output dc offset voltage (V O1 –V O2 ) is primarily a
Power supply rejection is provided by the capacitors (C1
In addition to providing filtering, C1 and C2 also affect the
resistors. The graph of Figure 1 indicates the
I IB ]. V O2 is shifted positive an equal amount.
100 Hz), and the
DESIGN GUIDELINES
MC34119
Chip Disable
IC to conserve power, or for muting, or both. When at a Logic
“0” (0 V to 0.8 V), the MC34119 is enabled for normal
operation. When Pin 1 is at a Logic “1” (2.0 V to V CC V), 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 k . The power supply current (when disabled) is
shown in Figure 15.
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 s, and turn on–time is 12 ms–15 ms.
Both times are independent of C1, C2, and V CC .
FC2 do not change as they are powered from V CC . The
outputs, V O1 and V O2 , 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.
Power Dissipation
IC) for various combinations of V CC , R L , and load power. The
maximum power which can safely be dissipated within the
MC34119 is found from the following equation:
where T A is the ambient temperature; and JA is the package
thermal resistance (100 C/W for the standard DIP package,
and 180 C/W for the surface mount package.)
application, is found from the following equation:
where I CC is obtained from Figure 15; and I RMS is the RMS
current at the load; and R L is the load resistance.
curves), and a peak working load current of 200 mA, define
the operating range for the MC34119. The operating range is
further defined in terms of allowable load power in Figure 14
for loads of 8.0 , 16
The Chip Disable (Pin 1) can be used to power down the
Muting, defined as the change in differential gain from
When the MC34119 is disabled, the voltages at FC1 and
Figures 8 to 10 indicate the device dissipation (within the
The power dissipated within the MC34119, in a given
Figures 8 to 10, along with Figures 11 to 13 (distortion
Figure 1. Turn–On Time versus C1, C2 at Power–On
360
300
240
180
120
60
P D = (V CC x I CC ) + (I RMS x V CC ) – (R L x I RMS 2 )
0
0
C1 = 5.0 F
2.0
MOTOROLA ANALOG IC DEVICE DATA
P D = (140 C – T A )/ JA
C1 = 1.0 F
C2, CAPACITANCE ( F)
and 32 . The left (ascending) portion
4.0
6.0
V CC switching from
0 V to 6.0 V
8.0
10