NF WAVE FACTORY WF1967, Инструкция по эксплуатации

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1.2 Operating Principles
WF1967/WF1968
1-4
1.2 Operating Principles

WF1967 Block Diagram
2.5ppm VCTCXO
30MHz
SYSTEM
CONTROLLER
(CPU, ROM, RAM,
REMOTE I/F,
MISC LOGIC)
AC/DC
DC/DC
for LOGIC
（シャーシ電位）
FAN
POWER
PWR
CNTL
EN
DC/DC
for ANALOG
+12V
FCTN
OUT
SYNC/SUB
OUT
100
～
230V
MOD/ADD
IN
10MHz REF IN
REF OUT
TRIG IN
USB GPIB
～ LINE
アイソレーション
外部変調 /
外部加算
切換え
各種同期 /
スイープ
X
ドライブ /
副波形出力
切換え
PG AMP
COMPARATOR
840MS/s
16bit 2ch
D/A
×
2
オーバ
サンプリング
D/A
OFFSET
VCO,
PLL
400kHz BW
1Mw
SSRAM
波形メモリ
16Mbit
±
10V
100MHz BW
0/-10/-20/-30dB
LPF
±
1V
MAIN
ANALOG
DDS
FPGA
D/A
Vref
Ref
16
16
CONT
ANALOG CONT.
約
2.2MS/s
TTL/
±
3V
LPF
LPF
A/D
PWR AMP
ATT
FRONT
PANEL
UNIT
USB
MEMORY
LAN
(option)
MULTI I/O
Figure 1-1 WF1967 Block Diagram

Analog Section

DDS (Direct Digital Synthesizer) operates on a clock of 840MHz or 420MHz and generates
various types of oscillations and waveforms. The DDS also generates of modulation, sweeps
and bursts.

Digital waveform signals generated by DDS are controlled by the specified polarity (normal
or inversed) and amplitude range (-FS/0, ±FS, 0/+FS). After the amplitude is digitally
adjusted, the waveform is input to the D/A converter.

Also, the D/A converter, analog amplitude control is performed.
waveform is converted into analog signal is smoothed by the LPF (low pass filter).

The amplitude is controlled in 10dB steps by the PG AMP (variable gain amp).

An external addition signal and DC offset are added to the PG AMP output. If an output
voltage of ± 400mV/open or less, attenuator of 1/5x is applied. If an output voltage greater
than ±2V/open, 5x amplifier is applied.
Analog section
Waveform
memory
Isolation
Approx. 2.2 MS/s
×2 over
sampling
External
modulation/
External
addition
switching
Each type of
synchronization/
sweep X drive/
sub waveform
signal switching
(Chassis potential)