MC33215B Freescale Semiconductor, MC33215B Datasheet - Page 8

• Manufacturer Part Number: MC33215B
• Manufacturer: Freescale Semiconductor

Specifications of MC33215B

• Max Transmitter Gain: 58dB
• Receiver Gain (max): 27dB
• Operating Temp Range: -20C to 70C
• Package Type: SDIP
• Pin Count: 42
• Operating Current: 15mA
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Lead Free Status / Rohs Status: Not Compliant

Figure 18, the MC33215 will be described in three parts: line
driver and supplies, handset operation, and handsfree
operation. The data used refer to typical data of the
characteristics.
LINE DRIVER AND SUPPLIES
telephone line termination and provides the necessary
supply points.
AC Set Impedance
line driver and its external components can be approximated
with the equivalent circuit shown in Figure 2.
inductor calculates as 1.6 H. Therefore, in the audio range of
300 Hz to 3400 Hz, the set impedance is mainly determined
by Z
Balance Return Loss BRL is shown in Figure 3.
components is seen for the lower frequencies (Inductor) and
the higher frequencies (C
DC Set Impedance
is partly consumed by the circuitry connected to V
the rest flows into Pin VLN. At Pin VLN, the current is split up
8
Based on the typical application circuit as given in
The line driver and supply part performs the ac and dc
The ac set impedance of the telephone as created by the
With the component values of the typical application, the
The influence of the frequency dependent parasitic
The line current flowing towards the MC33215 application
5.0
40
35
30
25
20
15
10
C
10 n
VDD
0
100
VLN
Figure 2. Equivalent of the AC impedance
. As a demonstration, the impedance matching or
Inductor
Z
620
C
100
VDD
Slope
VDD
Figure 3. Balance Return Loss
+
+
R
Z
R
R
2.2 k
bal
SLP
11
SLB
f, FREQUENCY (Hz)
REG1
VLN
) by a decreasing BRL value.
x
1000
x C
1
R
360 k
C
220 n
Freescale Semiconductor, Inc.
)
REG
REG1
REG
For More Information On This Product,
R
R
REG1
REG2
x
R
R
REG
SLP
11
DESCRIPTION OF THE CIRCUIT
Go to: www.freescale.com
Slope
DD
Inductor
10000
while
MC33215
into a small part for biasing the internal line drive transistor
and into a large part for supplying the speakerphone. The
ratio between these two currents is fixed to 1:10. The dc set
impedance or dc setting of the telephone as created by the
line driver and its external components can be approximated
with the equivalent of a zener voltage plus a series resistor
according to:
If R
becomes equal to 1.
the assumption that I
be simplified to:
at 20 mA of line current with a slope of 20 . Adding a 1.5 V
voltage drop for the diode bridge and the interruptor, the dc
voltage at tip–ring will equal 5.7 V.
requirement, this can be done by adjusting the resistors
R
slope are varied. It is not advised to change the resistor R
since this changes many parameters. The influence of R
and R
10 mA, the given dc mask relations are no longer valid. This
is the result of an automatic decrease of the current drawn
With:
REG1
V zener
ILN
R
With the values shown in the typical application and under
In the typical application this leads to a line voltage of 4.2 V
If the dc mask is to be adapted to a country specific
As can be seen in Figure 4, for low line currents below
slope
REG2
8.0
6.0
4.0
2.0
12
10
0
REG2
+
0
and R
VLN
I
line
+
+
is not mounted, the term between the brackets
is shown in Figure 4.
Figure 4. Influence of R
R
0.2 x
+
REG2
– I
SLP
11
VLN
20
3.8 V
MOTOROLA ANALOG IC DEVICE DATA
VDD
^
R
R
, as a result, the zener voltage and the
REG1
REG2
x
+
1
R
R
VDD
3.8 V
REG1
REG2
)
)
V zener
1
= 365 k
= 220 k
on the DC Mask
R
R
= 1.0 mA, the above formulas can
)
= 470 k
= Infinite
40
REG1
REG2
I
)
R
R
line
I
line
REG1
REG2
)
I
(mA)
line
– 1.0 mA x 20
)
ILN x R
.
REG1
x 20
60
10 A x R
R
R
REG1
REG2
and R
R
R
slope
REG1
REG2
= 470 k
= 220 k
80
REG2
= 365 k
= Infinite
REG1
REG1
SLP
100