OPA2320-Q1_15 Datasheet, PDF (21/31 Pages) Texas Instruments – Precision, 20-MHz, 0.9-pA, Low-Noise, RRIO,CMOS Operational Amplifier

www.ti.com
OPA2320-Q1
SLOS884 – SEPTEMBER 2014
One point to observe when considering the MFB filter is that the output is inverted, relative to the input. If this
inversion is not required, or not desired, a noninverting output can be achieved through one of the following
options:
1. adding an inverting amplifier
2. adding an additional second-order MFB stage
3. using a noninverting filter topology, such as the Sallen-Key (see Figure 44).
MFB and Sallen-Key, low-pass and high-pass filter synthesis is quickly accomplished using TI’s FilterPro™
program. This software is available as a free download at www.ti.com.
R3
549 Ω
C2
150 pF
R1
549 Ω
R2
1.24 kΩ
V_(V+)
V_I
C1
1 nF
OPA320-Q1
V_O
V_(V–)
Figure 43. Second-Order Butterworth 500-kHz Low-Pass Filter
220 pF
1.8 kΩ
19.5 kΩ 150 kΩ
V_(V+)
V_I = 1 V_RMS
3.3 nF
47 pF ^OPA320-Q1
V_O
V_(V–)
Figure 44. OPA2320-Q1 Configured as a Three-Pole, 20-kHz, Sallen-Key Filter
Copyright © 2014, Texas Instruments Incorporated
Product Folder Links: OPA2320-Q1
Submit Documentation Feedback
21