YOKOGAWA FG420, Руководство пользователя

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2 IM FG410-01EN
1.OVERVIEW
1.2 Operating Principles
FG410 block diagram
ANALOG
REF OUT
TRIG IN
10MHz REF IN
for ANALOG
+12V
100V...230V
～
LINE
MOD/ADD
IN
FCTN
OUT
SYNC/SUB
OUT
A/D LPF
LPF
D/A
DC OFFSET
120MHz
±10Vmax
PGA
0/-10/-20/-30dB
LPF
±1V
×2
TTL/±3V
×5
±2Vmax
EXTERNAL
MODULATION
EXTERNAL
ADDITION
ISOLATION
DDS
WAVE
MEMORY
16bit
512Kw
16bit-
2CH
D/A
CLOCK
GENERATOR
20MHz
SYSTEM
CONTROLLER
MULTI
I/O
GPIB USB
FRONT
PANEL
UNIT
AC/DC
POWER
SUPPLY
FAN
for SYSTEM
CONTROLLER
Analog block
• The DDS (digital direct synthesizer) uses a 120 MHz clock to generate various types of oscillation
and waveforms. Modulation, sweep, burst, and sequence are also processed within the DDS.
• The digital waveforms generated by the DDS are controlled to the specified polarity (normal,
inversed) in the amplitude range ( - FS/0, ±FS, 0/+FS), and following digital amplitude adjustment,
the signal is input into the digital to analog (D/A) converter.
• The waveform converted into an analog signal by the D/A is then smoothed by the lowpass filter
(LFP), and the amplitude is controlled in 10 dB steps by the programmable gain amplifier (PGA).
• The external addition signal and DC offset are added to the PGA output. When an output voltage
exceeding ±2V/open is required, output is done via the ×5 amplifier.
• The maximum output voltage of the product is either 20 Vp-p or 4 Vp-p depending on whether or
not the ×5 amplifier is used. Also depending on this, the external addition gain is either ×10 or ×2.
• After passing through the LPF, the external modulation signal undergoes A/D conversion and is
then input to the DDS.