LG -T510 Service Manual page 57

3. TECHNICAL BRIEF
Microphone Supply
X-GOLD™215 has a single ended power-supply concept for electret microphones:
For both modes a minimal load capacitance of t.b.d. nF is necessary to guarantee stable operation of the
buffer.
The maximal load capacitance must not exceed t.b.d. nF.
2 microphone supplies VMIC and VUMIC are available. The supply VUMIC has a ultra-low-power mode, where
the current consumption is minimum, whilst at the same time the noise performance is reduced.
For this purpose the VUMIC is directly supplied out of the VMIC regulator, the Mic-Buffer can be switched off
and only the quiescent current of the VMIC regulator is present.
This mode can be used to supply a headset and allow accessory detection with highly reduced current
consumption For normal operation the supply can be switched to normal operation mode with improved
noise performance. In case of an digital microphone VMIC can be used for supplying this microphone.
Figure 3.12.5 Typical Microphone Supply Generation (alternative)
LGE Internal Use Only - 57 - Copyright © 011 LG Electronics. Inc. All right reserved.
Only for training and service purposes