LTC1043

1

1043fa

■

Instrumentation Front End with 120dB CMRR

■

Precise, Charge-Balanced Switching

■

Operates from 3V to 18V

■

Internal or External Clock

■

Operates up to 5MHz Clock Rate

■

Low Power

■

Two Independent Sections with One Clock

The LTC

switched capacitor instrumentation building block. A pair

of switches alternately connects an external capacitor to

an input voltage and then connects the charged capacitor

across an output port. The internal switches have a

break-before-make action. An internal clock is provided

and its frequency can be adjusted with an external

capacitor. The LTC1043 can also be driven with an external

CMOS clock.

The LTC1043, when used with low clock frequencies,

provides ultra precision DC functions without requiring

precise external components. Such functions are

differential voltage to single-ended conversion, voltage

inversion, voltage multiplication and division by 2, 3, 4, 5,

etc. The LTC1043 can also be used for precise V–F and

F–V circuits without trimming, and it is also a building

block for switched capacitor filters, oscillators and

modulators.

The LTC1043 is manufactured using Linear Technology’s

enhanced LTCMOS

Dual Precision

Instrumentation Switched Capacitor

Building Block

, LTC and LT are registered trademarks of Linear Technology Corporation.

DESCRIPTIO

■

Precision Instrumentation Amplifiers

■

Ultra Precision Voltage Inverters, Multipliers

and Dividers

■

V–F and F–V Converters

■

Sample-and-Hold

■

Switched Capacitor Filters

Instrumentation Amplifier

CMRR vs Frequency

TYPICAL APPLICATIO

LTCMOS is a trademark of Linear Technology Corporation.

FREQUENCY OF COMMON MODE SIGNAL

100

20

100

120

140

1k

10k

100k

LTC1043 • TA02

80

60

40

LTC1043 • TA01

0.01

µF

–5V

–5V

5V

DIFFERENTIAL

INPUT

12

11

16

4

7

13

17

∆

∆

1

µF

1

µF

R2

R1

3

2

4

1

8

CMRR > 120dB AT DC

CMRR > 120dB AT 60Hz

DUAL SUPPLY OR SINGLE 5V

GAIN = 1 + R2/R1

≈ 2µV/°C

T

COMMON MODE INPUT VOLTAGE INCLUDES THE SUPPLIES

1/2 LTC1043

5V

1/2 LTC1013

1

µF

(EXTERNAL)

8

14

–

+

FEATURES

APPLICATIO S