LTC1992 Family

29

1992fb

APPLICATIONS INFORMATION

Figure 4. Basic Fully Differential Amplifier Application Circuits (Note: Single-Ended to Differential Conversion is

Easily Accomplished by Connecting One of the Input Nodes, +VIN or –VIN, to a DC Reference Level (e.g., Ground))

–

–

+

+

RIN

RIN

RFB

RFB

Gain Block

–VIN

+VIN

VOCM

–VOUT

+VOUT

–

+

RIN

VIN

RFB

VOUT

RFB

RIN

GAIN =

LTC1992

–

–

+

+

RIN

RIN

RFB

RFB

AC Coupled Gain Block

–VIN

+VIN

VOCM

–VOUT

+VOUT

–

+

RIN

CIN

CIN

CIN

VIN

RFB

VOUT

LTC1992

–

–

+

+

RIN

RIN

RFB

RFB

Single Pole Lowpass Filter

–VIN

+VIN

RFB

RIN

P

S + P

; P =

VOCM

–VOUT

+VOUT

–

+

RIN

VIN

RFB

C

VOUT

H(S) = HO •

WHERE HO =

LTC1992

C

C

1

RFB • C

–

–

+

+

R1

R3

R3

R4

R4

R1

R2

R2

3-Pole Lowpass Filter

–VIN

+VIN

R2

R1

; P =; O =

VOCM

–VOUT

1992 F04

+VOUT

–

+

R1

R3

R4

R2

C1

C2

VOUT

WHERE HO =

LTC1992

C3

C1

C1

1

R4C3

1

R2R3C1C2

C2

2

C3

2

P

S + P

H(S) = HO

()

O

2

S2 + S

+

O

Q

O

2

()

VIN

RFB

RIN

; P =

HO =

1

RIN • CIN

S

S + P

H(S) = HO •

C2

C1

R1 • √R2R3

R1 R2 + R1 R2 + R2 R3

•

Q =