Datasheet

LMV721-N, LMV722-N
www.ti.com SNOS414I –AUGUST 1999–REVISED AUGUST 2013
Figure 31. Simple Low-Pass Active Filter
(5)
Figure 32. Frequency Response of Simple Low-pass Active Filter in Figure 31
Note that the single-op-amp active filters are used in to the applications that require low quality factor, Q(≤ 10),
low frequency (≤ 5KHz), and low gain (≤ 10), or a small value for the product of gain times Q(≤ 100). The op amp
should have an open loop voltage gain at the highest frequency of interest at least 50 times larger than the gain
of the filter at this frequency. In addition, the selected op amp should have a slew rate that meets the following
requirement:
Slew Rate ≥ 0.5 x (ω
H
V
OPP
) X 10
−6
V/µsec
where
• ω
H
is the highest frequency of interest
• V
OPP
is the output peak-to-peak voltage
Figure 33. A Battery Powered Microphone Preamplifier
Copyright © 1999–2013, Texas Instruments Incorporated Submit Documentation Feedback 13
Product Folder Links: LMV721-N LMV722-N