ETS2228 Maintenance Manual
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Page 8, Total 43
Signal
Modules
Function Description
VREG_PHONE
the secondary power conversion module
the output of the secondary
power:4.44V
V_BATT
Battery
－
>PM6610
the battery output voltage
CHG_EN
PM6610->TL494
PM6610:control the output
List 1 Battery Charging/Discharging Module Signals
Figure 3 Battery charging Circuit
Battery is connected to the output of the secondary power supply(4.4V) directly. When there is no
external power supply, battery powers the system supply through the signal VREG_PHONE, and there is
no special discharging control circuit.
Audio Interface Circuit
ETS2228 audio interface includes handle receiver (the microphone and earphone is included),
speaker interface and hands-free MIC interface. The power of speaker is quit bigger than the others,
which must be amplified through the audio amplifier, but for hands-free MIC interface and handle
receiver can be connected directly.
1
）
Handset MIC Interface
。
Bead and capacitor constitute the filter circuit.
