LMV321M7SLASHNOPB datasheet(23/52 Pages) TI1

23 / 52 page

LMV321-N, LMV321-N-Q1, LMV358-N

LMV358-N-Q1, LMV324-N, LMV324-N-Q1

www.ti.com

SNOS012J – AUGUST 2000 – REVISED DECEMBER 2014

Typical Applications (continued)

9.2.3.3 Single-Supply Inverting Amplifier

There may be cases where the input signal going into the amplifier is negative. Because the amplifier is

operating in single supply voltage, a voltage divider using R3 and R4 is implemented to bias the amplifier so the

input signal is within the input common-mode voltage range of the amplifier. The capacitor C1 is placed between

the inverting input and resistor R1 to block the DC signal going into the AC signal source, VIN. The values of R1

and C1 affect the cutoff frequency, fc = 1/2πR1C1.

As a result, the output signal is centered around mid-supply (if the voltage divider provides V+/2 at the non-

inverting input). The output can swing to both rails, maximizing the signal-to-noise ratio in a low voltage system.

Figure 59. Single-Supply Inverting Amplifier

9.2.4 Sallen-Key 2nd-Order Active Low-Pass Filter

The Sallen-Key 2nd-order active low-pass filter is illustrated in Figure 60. The DC gain of the filter is expressed

(2)

Its transfer function is

(3)

Figure 60. Sallen-Key 2nd-Order Active Low-Pass Filter

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Product Folder Links: LMV321-N LMV321-N-Q1 LMV358-N LMV358-N-Q1 LMV324-N LMV324-N-Q1

LMV321M7/NOPB Datasheet(PDF) 23 Page - Texas Instruments