PS-SAU-1900E
Mar. 8
th
,1999 (Rev. 0.0)
--- CONFIDENTIAL AND PROPRIETARY ---
11
2.2.1. Functional
Description.
The Main Board acts primarily as an interface between the CDMA Printed Circuit Assemblies (PCAs), the
Power Supply Module, and the external connectors. It contains these major hardware functions:
1. External
Interfaces.
2. Line Interface Module.
3. Battery Management Module.
4. Interface between the above functions and the CDMA Modules.
5. Power
distribution.
These functions will be discussed in detail in subsequent sections of this document.
2.2.2. I/O
Definitions.
The primary Main Board I/O points are listed below. Note that this list is not totally inclusive. It contains
only the I/O which is critical in defining the operation of the product.
Connector
Pin
Count
Function
RJ11-A
2 or 4 Analog telephone device interface. Two wires (TIP and RING).
RJ11-B
2 or 4 Analog telephone device interface. Two wires (TIP and RING).
Paralleled with RJ11-A.
DC Power Input
2
Rectified DC power input, from ac / dc converter transformer.
Service
3
Two wire serial I/O interface, with ground reference pin. Serial data
is output as a unipolar TTL level signal, referenced to the LAU’s
internal ground. Maximum data rates are 115.2 kbaud.
RF Antenna
1
RF I/O point. Mating point for external antenna.
Table 2.2.2.-1: Main Board I/O Primary Definitions.
2.2.3.
Critical Electrical Characteristics.
The Main Board provides the primary protection circuitry to meet the product’s RF Immunity and ESD
specifications. These requirements are defined earlier in this specification.
2.3.
Line Interface Unit (LIU).
The LIU provides the interface between the digital baseband module and the external analog telephone
unit(s). It’s primary functions and provisions are as follows:
•
Loop start interface compatibility.
•
AC loop impedance matching for all states (on hook, off hook, signaling, ringing, and talk)
•
DC loop voltage supervision to external analog telephone device for all states (on hook, off hook).
•
Caller ID compatible FSK signaling.
•
Loop interfaces to monitor loop status.
•
Analog band-limited talk/receive interface between LAU and analog telephone unit.
•
DTMF Detection and Decoder capability.
