User Guide

After Sales
Technical Documentation
Compact Handsfree Unit PHF–2
Page 6 Original, 11/94
Technical Specifications
Modes of Operation
Power Off : The DH3–module does not receive a supply volt-
age at the DC–connector (X100), hence no
voltages are present on the module.
Standby : The module receives a supply voltage at the DC–
connector but the M2BUS–line (X400) is low (logic
”0” state) because the phone is off and the battery
is fully charged. The switching regulator is off and
there is no supply voltage for the audio.
Power On / Speaker Off : The M2BUS–line is high (logic ”1” state) so the
switching regulator supplies charging current to the
phone. The supply voltage for the audio is on but
the PHFS–line (X400) is low (”0” state) so the HF–
speaker is muted.
Power On / Speaker On : The switching regulator supplies a charging
current to the phone. The supply voltage for the
audio is on and the PHFS–line is high (logic ”1”
state) so the HF–speaker is on.
Table 2. List of Connectors
CONNECTOR NAME CODE NOTES POLES
DC–Supply Connector X100 Power Supply Input Vdc 2–pole
HF–Microphone Connector X200 Microphone Input HFMIC 2–pole
HF–Speaker Connector X300 Speaker Output HFSP 2–pole
System Connector X400 Phone Cable Connector HHP 8–pole