Fig. 3.9 Data Flow In Esipro - Siemens BS-240 Technical Description

Technical Description (TED:BSS)
BS-240/241
Fig. 3.9 Data Flow in ESIPRO
36
EPSU (Power Supply Unit)
The EPSU is the DC/DC converter for the ECU for all applications. The EPSU generates
the voltages +26V/+28V, +12V, +5,3V and -5,3V for the analog circuitry and +3.3V for
the digital circuitry from a -48V primary input voltage. The only interface relevant change
was the change of the analog bias voltage for the EPWRSTD to +12V. The EPSU is
mechanically incorporated in the ECU.
The EPSU is a slightly modified version of the PSU of the GSM CU. In this document,
not all Interface names are changed to EPSU. Therefore, PSU can be seen as a
synchronym for EPSU in this document.
Main differences between ECU and CU
The following major changes to the CU HW were made to support the EDGE function-
ality:
1. New Power Amplifier with better linearity and approximately 3 dB higher peak power
capability
2. New power levelling concept including a digital power control loop
3. New TX-VGA and PWRDET due to new power control
4. Adaptive predistortion to linearize the transmitter
5. New module Predistortion receiver (PDRX)
6. New IQDEM (IF-sampling ADC) with higher dynamic
7. RXA adaption to new IQDEM
8. New Power Supply Unit (EPSU) with higher power capability
Information
Base Station System
A30808-X3247-L14-2-7618