Nokia 616 Service Manual page 188

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Figure 9: VAudio HW-Realization
To enable this a LDO regulator is used to provide optimized headroom to Vcar. Because
the Audio-Amplifier is sensitive regarding power supply-noise, this regulator has to fulfill
this demand to enable noise free audio output on HF path. The output voltage is deter-
mined by the Resistor net R122 and R126 at 10V 5% accuracy.
VEBpwr
This is used to supply the EB (via the VIDU-switch), the display unit and the input device
with power. VEBpwr power supply is able to provide 3A maximum current at 4.2V 5%.
The maximum allowed ripple is 50mV because of the Bluetooth ripple-demand. When
this demand is not fulfilled the Bit-error rate of the Bluetooth module will increase. This
voltage regulator shall not provide exceptional heat dissipation, this is guaranteed by
using a switch-mode regulator that is used with internal Switch.
Figure 10: VEBpwr regulator HW realization
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