1-2
SM 701730-01E
1.2
Function of Each Assembly
Analog Board Assembly
The analog board assembly has a coupling switch for AC/DC, 1 M
Ω
/50
Ω
, and GND/
Measure and a switch circuit for the attenuator (1:1, 10:1, 100:1, 200:1). Relays are
used to make the switch. In addition, a one-chip amplifier IC and an analog multiplexer
IC are onboard.
The one-chip amplifier IC has a gain switch circuit, a low-pass filter circuit (external
capacitor), a trigger coupling circuit (external capacitor), and a trigger bandwidth limiting
circuit (external capacitor). In addition, the input offset voltage and the trigger level are
varied using an external DC voltage input. The frequency bandwidth of the IC is
approximately 600 MHz.
As indicated in figure 1.1 or figure 1.3, the vertical sensitivity from 10 V/div to 2 mV/div is
achieved by switching the gain on the attenuator and the one-chip amplifier IC.
The analog multiplexer IC is used to achieve the interleave operation. During the
interleave operation, the input signal of CH1 (CH3) is supplied to the A/D converter of
CH2 (CH4). The frequency bandwidth of the IC is approximately 2 GHz.
The above-mentioned control signal, offset, and DC voltage for the trigger level are
supplied by the analog front-end controller (AFC) IC on the AD4 board (or the AD2 board
for the DL1720E) assembly.
Table 1.1 Setting Range and Amplifying Level
Setting Range
Attenuator Division Ratio
Amplifying Rate
2 mV/div
1/1
×
25
5 mV/div
1/1
×
10
10 mV/div
1/1
×
5
20 mV/div
1/1
×
2.5
50 mV/div
1/1
×
1
100 mV/div
1/10
×
5
200 mV/div
1/10
×
2.5
500 mV/div
1/10
×
1
1 V/div
1/100
×
5
2 V/div
1/100
×
2.5
5 V/div
1/100
×
1
10 V/div
1/200
×
1
The setting range here is for the 1:1 probe setting.
