Datasheet

Functional Description
MC13783 Technical Data, Rev. 3.5
34 Freescale Semiconductor
4.3.5.5 Loudspeaker Amplifier Alsp
The concept of the Alsp amplifier is especially developed to be able to drive one loudspeaker during
handset, speakerphone and alert modes. It adopts a fully differential topology in order to be able to reach
high PSRR performance while Alsp is powered directly by the telephone battery. The feedback network
of the Alsp amplifier is fully integrated.
Under worst case conditions the dissipation of Alsp is considerable. To protect the amplifier against
overheating, a thermal protection is included which shuts down the amplifier when the maximum
allowable junction temperature within Alsp is reached.
4.3.5.6 Headset Amplifiers Ahsr/Ahsl
The Ahsr and Ahsl amplifiers are dedicated for amplification to a stereo headset, the Ahsr for the right
channel and Ahsl for the left channel. The feedback networks are fully integrated.
The return path of the headset is provided by the phantom ground which is at the same DC voltage as the
bias of the headset amplifiers. This avoids the use of large sized capacitors in series with the headset
speakers. All outputs withstand shorting to ground or to phantom ground.
Table 19. Amplifier Alsp Performance Specifications
Parameter Condition Min Typ Max Units
Differential Output Swing BP = 3.05 V — 5.0 — — V
PP
BP = 3.4 V in 8Ω —5.6——V
PP
Supply Voltage — — 3.05 — 4.65 V
Gain 1.0 kHz Vin = 100 mVpp 5.8 6 6.2 dB
THD (2
nd
and 3
rd
) 1.0 kHz, BP = 3.4 V V
OUT
= 5 Vpp — 3 5 %
1.0 kHz, BP = 4 V V
OUT
= 5 Vpp — 1 3 %
1.0 kHz V
OUT
= 1 Vpp — — 0.1 %
1.0 kHz Vout = 10 mVrms — — 0.1 %
PSRR with respect to BP
20 Hz – 20 kHz
inputs AC grounded
A Weighted
—90——dB
Input Noise A weighted — — — 20 μV
RMS
Load Impedance Resistance — 6.4 8 38 Ω
Table 20. Amplifiers Ahsr and Ahsl Performance Specifications
Parameter Condition Min Typ Max Units
Singled-Ended Output Swing 32 Ohm load
16 Ohm load
2
1.6
2.2
1.8
—V
PP
Gain 1.0 kHz Vin = 100 mVpp -0.2 0 0.2 dB