MC33215B Freescale Semiconductor, MC33215B Datasheet - Page 13

• 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

output includes, besides the loudspeaker amplifier gain, also
the attenuation of the sidetone network and the internal gain
from RXI to RLS. When in receive mode, see under duplex
controller, the gain from RXI to RLS is maximum and equals
24 dB at maximum volume setting. The attenuation of the
sidetone network in the typical application equals 24.6 dB
which makes an overall gain from line to loudspeaker of
25.4 dB. Due to the influence of the line length AGC on the R
amplifier, the gain will be reduced for higher line currents.
bootstrap stage which ensures maximum output swing under
all supply conditions. The major advantage of this type of
output stage over a standard rail–to–rail output is the higher
stability. The principle of the bootstrap output stage is
explained with the aid of Figure 9.
filtering of the loudspeaker with the big capacitor C
requires that LSB is biased at VLS. In fact, because of the
filtering, LSB is kept at VLS/2 above the LSO output even if
LSO contains an ac signal. This allows the output transistor
MOTOROLA ANALOG IC DEVICE DATA
The total gain from the telephone line to the loudspeaker
The output stage of the MC33215 is a modified all NPN
The output LSO is biased at half the supply VLS while the
140
120
100
40
80
60
20
0
2.0
3.0
–0.5 VLS
0.5 VLS
A. Peak–to–Peak Limiter Active
0
4.0
0.5 VLS
VLS (V)
VLS
Figure 10. Loudspeaker Amplifier Output Power with External Supply
5.0
0
Freescale Semiconductor, Inc.
For More Information On This Product,
6.0
R
Figure 9. Loudspeaker Output Stage
LSP
R
LSP
Go to: www.freescale.com
= 25
Loudspeaker
7.0
= 50
C
LSO
MC33215
LSO
8.0
x
VLS
T2 to be supplied for output signals with positive excursions
up to VLS without distorting the output signal. The resulting
ac signal over the loudspeaker will equal the signal at LSO.
As an indication of the high performance of this type of
amplifier, in Figure 10, the output power of the loudspeaker
amplifier as a function of supply voltage is depicted for 25
and 50
disabled. As can be seen, in case the peak–to–peak limiter is
disabled, the output power is roughly increased with 6.0 dB,
this at the cost of increased distortion levels up to 30%.
amplifier output power is limited not only by the supply
voltage but also by the telephone line current. This means
that in telephones the use of 25
preferred over the use of the cheaper 8.0
gives the output power into the loudspeaker for a line
powered application and two different dc settings with the
peak–to–peak limiter active. In case the peak–to–peak limiter
is disabled the output power will be increased for the higher
line currents up to 6.0 dB.
LSO
PGD
In a telephone line powered application, the loudspeaker
LSB
300
250
200
150
100
50
0
2.0
loads with both the peak–to–peak limiter active and
T2
T1
1.5 VLS
0.5 VLS
VLS
3.0
VLS
B. Peak–to–Peak Limiter Disabled
4.0
VLS (V)
5.0
or 50
6.0
types. Figure 11
R
R
LSP
LSP
speakers is
7.0
= 25
= 50
13
8.0