Replacement Parts; Theory Of Operation; Figure 21: Diagram Of The Ada400A Differential Preamplifier - Tektronix ADA400A Instruction Manual

Maintenance

Replacement Parts

Theory of Operation

AC-GND-DC
Input Coupling/
+
Input Protection
1 M / 1 Ω
Select
High-Z
Input
Attenuator
(1/1, 1/100)
Input Coupling/
- -
Input Protection
AC-GND-DC

Figure 21: Diagram of the ADA400A Differential Preamplifier

56
Refer to the Replaceable Parts section beginning on page 59 for a list of
customer replacement parts.
Figure 21 illustrates the functional blocks of circuitry from left to right in the
order of input to output. The darker boxes in the illustration designate front panel
controls and lines with arrows indicate the functional blocks that the controls
affect.
ADA400A Differential Preamplifier
DC
Offset Coarse, Fine
High-Impedance
Amplifier
+
+
- -
Gain = X10
Gain .1, 1, 10, 100
On/Off,
Low-Z
Low-Pass
Attenuator
Filter
(1/1, 1/10)
Upper Bandwidth Select
100 Hz, 3 kHz, 100 kHz 1 MHz
Scale Factor
Coding
TEKPROBE
Interface
Overrange
Detect
Output
Amplifier
50 Ω
Gain = X10
Output
Cable
ADA400A Differential Preamplifier
Oscilloscope
Signal Out
+15V
- - 15V
+5V
Data
Ground