User Guide

Technical Documentation
NHD–4
System Module
P.A.M.S
Page 4–29
Original 11/97
Either of these two signals can be viewed with an oscilloscope. With an
RF input of 881.62 MHz CW into a CDMA receiver tuned to channel 384,
either of these signals will appear as sine waves of approximately 190
mVpp magnitude, 100 kHz in frequency.
BFILCT (N2)
The BFILCT IC, N2 serves to filter the demodulated baseband I & Q
signals before delivering them to the CDRFI IC (N700) for A/D conversion.
This IC also amplifies the I & Q signals. The I & Q signals enter this IC at
pins 13 and 20 via C33 and C57 respectively. During normal operation
pin 3 of N2 will be pulsed about every 10 seconds by the RX_FIL_CAL
signal. The VBBFILM DC supply should be approximately 3.10 V at C36,
C55 or C56. About 3.00 V should exist at the pin 8, R791, R792 node.