5-20 Keysight N5227B Service Guide
Theory of Operation
Synthesized Source Group Operation
5-
A70 4-Port and A75 2-Port Low Frequency Extension (LFE) Board
Provides a 900 Hz to 100 MHz LFE signal for measurements. Refer to
www.keysight.com/find/pna
.
The Low Frequency Extension (LFE) option in the PNA consists of an LFE board
A70 4-port or A75 2-port) and a new 4-Port bias combiners (A70-A74). See
“A42–A45 60-dB Source Step Attenuators and A71–74 Bias Tee
Combiners (Optional)” on page 5-36
.
This board is designed to extend the frequency bandwidth at the low end,
down to 900 Hz. And, the high end of the LFE board is 100 MHz. Between
10 MHz and 100 MHz either LFE or non-LFE mode can be used.
The inputs and outputs connectors of the LFE board:
PNA 2 ports:
Inputs:
5
ACOM
System ground
6
GndSense
Ground sense for Analog In and Analog Out
Connected with 51.1 ohms to ACOM
7
AnalogIn1
Analog input:
±10 V @ 1.22 mV typical resolution
Rin > 1 M-ohm
BW
≥
1 MHz
ADC conversion time < 1 us typical
8
AnalogIn2
Analog input:
±10 V @ 1.22 mV typical resolution
Rin > 1 M-ohm
BW
≥
1 MHz
ADC conversion time < 1 us typical
9
Power Button
Open collector input
Active low replicates power button key press.
Table 5-4
PWR I/O Connector Pin Assignments
DB-9 Female Connector
Pin
Name
Description
