4. Current feedback channels(channel 1 & 4)
Command
20k
10k
ref
current feedback amp
power amp
7.5k
7.5k
X2
FAN8024CD
actuator
Sensing resistor
Rext Cext
• The reference voltage(ref) is given externally through pin 27.
• The input OP-amp output signal is amplified by (20K/10K) times and then fed to the current feedback amplifier.
• The current feedback amplifier compares the output current sensed input and command input then makes the controlled
output to eliminate delay effect of the load. Please refer to the application note for more information about current feedback
theory(http://www.fairchildsemi.com/an/AN/AN-4109.pdf).
• The DC gain of current feedback amplifier and power amplifier is unity, that is 1 [A/V]. Users can change the gain by
adding external resistor at the command input.
5. Channel 2 schematic
power amp
25k
10k
M
ref
• The reference voltage(ref) is given externally through pin 27.
• The input OP-amp can be used for several purposes, for example low pass filter, differential input coordinator, gain scaler
and so on.
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