GE LOGIQ P5 Service Manual page 153

GE H
EALTHCARE
D 5394141, R
IRECTION EVISION
5-4-2-3 Preamp in CL1TRX/BL1TRX
The Pre-Amplifier receives and amplifies each 64 echo signals. Then, all 64 echo signals (from 0 to
63ch) are outputted to the Analog to Digital converter to delay and sum. Following 32 echo signals (from
32 to 63ch) are simultaneously outputted to the ACWD ASSY via the ASIG ASSY.
The preamp module have main three blocks: Pre-amp and Gain Control and Mode control block.
The preamp module amplifies the echo signals. The mode control block selects a maximum gain code
via dedicated control signals from SYSCONPM(SYSCONCM). The analog signal provided by Gain
Control block gives total amplified gain. The block diagram above of the preamp module for a received
signal is given. Actually, there are 64 channels equivalent to figure above for a preamp module.
The Pre-amp block consists of Low Noise Amplifier (LNA) and Variable Gain Amplifier (VGA). A
received signal is amplified by LNA (fixed gain), then amplified by VGA (variable gain).
5
c h 0 c h 0
L N A L N A
c h 1 c h 1
L N A L N A
c h 2 c h 2
L N A L N A
c h 3 c h 3
L N A L N A
c h 6 3 c h 6 3
L N A L N A
Figure 5-12 Pre Amp Block Diagram For a Channel
Section 5-4 - Main Board Detail
A D C 1 0 b its A D C 1 0 b its
V C A V C A
A D C 1 0 b its A D C 1 0 b its
V C A V C A
A D C 1 0 b its A D C 1 0 b its
V C A V C A
A D C 1 0 b its A D C 1 0 b its
V C A V C A
A D C 1 0 b its A D C 1 0 b its
V C A V C A
LOGIQ™ P5 S M
EVICE ANUAL
5-13