Huawei Airbridge BTS3612A-1900 Technical Manual page 47

Technical Manual
Airbridge BTS3612A CDMA Base Station
Figure 3-9 Position of BBFM in BHPA module
The structure of the BBFM is shown in Figure 3-10.
BHPA
External
temperature
collection
Figure 3-10 Structure of BBFM module
MCU module
The MCU module implements the following functions:
- Collect and analyze the temperature information to generate PWM signals for
controlling the fan speed.
- Receive alarm signals generated by the BHPA module and fan alarm signals and
report to the BTRM module.
- Generate panel indicator signal.
- Communicate with the BTRM module.
BHPA interface module
BHPA
BBFM
BBFM
HPAU
Interface
circuit
Temperature
collection
Watchdog
Chapter 3 Radio Frequency Subsystem
MCU
3-19
System Principle
Panel indicator
driving alarm
signal isolation
circuit
Fan cover
PWM
Modulation
circuit
Serial port
Communication
BTRM
interface