LTC1043_15 Datasheet, PDF (1/16 Pages) Linear Technology – Dual Precision Instrumentation Switched Capacitor Building Block

LTC1043
Dual Precision
Instrumentation Switched Capacitor
Building Block
FEATURES
DESCRIPTIO
■ _{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}
U
APPLICATIO S
■ _{Precision Instrumentation Amplifiers}
■ _{Ultra Precision Voltage Inverters, Multipliers}
and Dividers
■ _{V–F and F–V Converters}
■ _{Sample-and-Hold}
■ _{Switched Capacitor Filters}
The LTC^®1043 is a monolithic, charge-balanced, dual
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^TM silicon gate process.
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTCMOS is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
Instrumentation Amplifier
5V
4
7
8
DIFFERENTIAL
INPUT
11
1µF
C_S
(EXTERNAL)
12
5V
3₊ ⁸
1µF
1/2 LTC1013 ¹
C_H
2_–
4
–5V
V_OUT
1µF
13
14
R1
R2
16
0.01µF
17
–5V
1/2 LTC1043
LTC1043 • TA01
CMRR > 120dB AT DC
CMRR > 120dB AT 60Hz
DUAL SUPPLY OR SINGLE 5V
GAIN = 1 + R2/R1
V_OS ≈ 150µV
∆ V_{OS ≈ 2µV/°C}
∆T
COMMON MODE INPUT VOLTAGE INCLUDES THE SUPPLIES
CMRR vs Frequency
140
C_S = C_H = 1µF
120
100
80
60
40
20
100
1k
10k
100k
FREQUENCY OF COMMON MODE SIGNAL
LTC1043 • TA02
1043fa
1