Datasheet

LM4140
www.ti.com SNVS053E –JUNE 2000–REVISED APRIL 2013
APPLICATION HINTS
INPUT CAPACITORS
Although not always required, an input capacitor is recommended. A supply bypass capacitor on the input
assures that the reference is working from a source with low impedance, which improves stability. A bypass
capacitor can also improve transient response by providing a reservoir of stored energy that the reference can
utilize in case where the load current demand suddenly increases. The value used for C
IN
may be used without
limit. Refer to the Typical Application section for examples of input capacitors.
OUTPUT CAPACITORS
The LM4140 requires a 1μF (nominally) output capacitor for loop stability (compensation) as well as transient
response. During the sudden changes in load current demand, the output capacitor must source or sink current
during the time it takes the control loop of the LM4140 to respond.
This capacitor must be selected to meet the requirements of minimum capacitance and equivalent series
resistance (ESR) range.
In general, the capacitor value must be at least 0.2μF (over the actual ambient operating temperature), and the
ESR must be within the range indicated in Figure 24, Figure 25 and Figure 26.
Figure 24. 0.22 μF ESR Range
Figure 25. 1 μF ESR Range
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