PS-SAU-1900E
Mar. 8
th
,1999 (Rev. 0.0)
--- CONFIDENTIAL AND PROPRIETARY ---
17
The PSM must conform to the following electrical characteristics, under all operating conditions, unless
specifically indicated.
Characteristic
Performance Criteria
Conditions
5V Supply Output
Max Current:
1.45 A.
DC Output:
4.85 to 5.25V.
Max Ripple:
< 100 mV
rms
.
Efficiency: >
90%
All operating temperatures, transmitter
at full power, external loop active with
full range of loads.
-24V Supply
Output
Max Current:
50 mA.
DC Output:
-22.0 to -26.0
V.
Max Ripple:
< 500 mV
rms
,
Efficiency: >
90%
All operating temperatures, transmitter
at full load, external loop active with full
range of loads.
-65V Supply
Output
Max Current:
100 mA.
DC Output:
-61.0 to -69.0 V.
Max Ripple:
< 500 mV
rms
Efficiency: >
80%
All operating temperatures, transmitter
at full load, external loop active with full
range of loads.
Power efficiency
(ac operation)
Talk Mode:
> 80% at max output.
Standby Mode: > 80% at max output.
All operating conditions, transmitter at
full power operation.
Power efficiency
(battery operation)
Talk Mode:
> 80% at max output.
Standby Mode: > 80% at max output.
All operating conditions, transmitter at
full power operation.
Table 2.4.2.-1: Primary PSU Electrical Characteristics.
2.5.
Battery Management Module (BMM).
The Battery Management Module (BMM) manages the distribution and source for the LAUs primary
power sources, battery and ac power. As such, it provides the following basic functions:
•
Monitors the status of the input ac power signal, and controls the switch-over between ac power
and battery reserve power when ac power failure occurs.
•
Measures the charge level of the reserve battery, and controls the charging input to the battery
according to the discharge level, battery temperature, and ambient temperature conditions.
•
Generates necessary power-on reset signals to other modules within the LAU, assuring proper
initialization when power is applied.
•
Provides output indications of certain power-related fault conditions.
2.5.1. Functional
Characteristics.
These are the functional requirements for the Battery Management Module.
Characteristic
Performance Criteria
Battery / AC Power Source Selection
The BMM controls the source of electrical power for
the LAU by monitoring the ac power input and the dc
battery level. The following criteria determine which
source provides the operating power for the LAU
circuitry:
•
If AC power is present on the 19 VOLTS IN line,
then battery supply power is turned of.
•
If Battery power is present and AC power is not,
