Application note
TS507
3.2
In-the-loop-compensation technique
The second technique is called the in-the-loop-compensation technique, because the
additional components (a resistor and a capacitor) used to improve the stability are inserted
in the feedback loop (see Figure 30).
Figure 30. In-the-loop compensation schematics
This compensation method allows, by a good choice of compensation components, to
compensate the original pole (caused by the capacitive load), and thus to improve stability.
The main drawback of this circuit is the reduction of the output swing, because the isolation
resistor is in the signal path.
Table 6 helps you to choose the best compensation components for different ranges of load
capacitors (and with RL = 10 kΩ) in voltage follower configuration.
Table 6.
Best compensation components for different load capacitor ranges in
voltage follower configuration for TS507 (with RL = 10 kΩ)
Load capacitor
range
RIL (kΩ)
CIL (pF)
Minimum gain
margin (dB)(1)
Minimum phase
margin
(degree)(1)
10 pF to 100 pF
1
250
17
55
100 pF to 1 nF
1
250
16
42
1 nF to 10 nF
1
630
11
27
1. Parameter guaranteed by design at 25°C.
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