The HFU–2 is a handsfree unit for DCT3 compatible handportable
phones. It provides rapid charging for the phone, a possibility to use HF–
operation and connections to the data–card and handset unit. The HF
box can be connected directly to the Mobile holder MCC–1 via the external cable.
HFU–2
Technical Summary
The HFU–2 has connections to car battery, car ignition sense, car radio
muting, antenna motor control, data–card, handset HSU–1, external
speaker and microphone. The unit has a System–connector that provides an interface to the Mobile holder MCC–1 via the external cable.
The unit consists of a rapid charger, HF–microphone– and speaker amplifiers, interface to handset, – datacard and –phone, voltage regulators and
control circuit (microprocessor).
The HFU–2 is always connected to the car battery. To save the car battery, HFU–2 goes in to the sleep mode if the car is not running and/or the
phone is not connected.
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PAMS
HFU–2
Technical Documentation
List of Modules
Name of moduleType codeMaterial
code
HF unitHFU–20694049Advanced handsfree unit
HF moduleED20200948ED2 Advanced hadsfree module
Assembly partsMHFU–20261602Mechanical Parts
Notes
Operation
Phone not connected (sleep mode):
When the phone is not connected the current consumption of
the device has been minimized. The switching mode power
supply (SMPS) and audio circuits has been turned off. HFU–2
is only waiting a phone to be connected.
Phone connected (active mode):
When the phone is connected to the HFU–2 it goes into the active mode. In the active mode the device provides charging
current to the phone. It also can provide hands free call option
using the external speaker and the external microphone or
micspeaker unit. If more private call wants to be made, the
phone itself can be used as a handset without losing the external antenna connection or with handset (option).
The phone controls all functions of HFU–2. In the active mode
the HFU–2 sends all state transitions to phone via mbus.
HFU–2 also provides car radio mute function during call.
HFU–2 can control the mobile antenna motor if it is installed to