User's Manual

Confidential
USERS MANUAL
19(31)
Document number Revision
1/198 17-5/FCP 101 3317 Uen A
5 Electrical Interface
This section describes each signal line of the electrical interface between the EDGE
modem and the host equipment application. A summary of the function of each signal is
provided, together with any additional relevant information.
Signals are described from the perspective of the EDGE modem and Daughter Card
circuitry. Consequently signals described as input are inputs to the modem, driven by the
host [host
⇒modem]. Likewise, signals described as output are driven by the modem in to
the host [modem
⇒host]. Bi-directional signal flow (I/O) is indicated by a double-headed
arrow [modem
⇔host]. In some instances the [daughter card] will be identified if the
modem circuitry is not directly involved, or where additional interface circuitry resides
between the host and the modem.
Signals which are pulled internally are identified in parentheses beside the signal name as
either (PU)=Pulled Up or (PD)=Pulled Down. Signals with no designation are not pulled
either way.
5.1 Power Interfaces
This section describes the power, ground, and other signals that control or indicate power
states.
• VIN
• 3V3
• VREF
• GND
5.1.1 VIN
Function: Daughter card power supply
Description: Primary voltage supply to switching regulator (5.5 to 20.0V).
Pin Numbers: 14, 15, 16, 17, 18, 19
Signal Names: VIN [host
⇒daughter card]
If not used: Required
Details:
Power provided by the host will range from 5.5V minimum to a maximum 20.0V,
dependent upon the battery discharge state. The Daughter Card has on board regulation
which regulates the supply range to a steady 3.6V by means of a switching regulator rated
at 3A max.