LTC1043
Dual Precision
Instrumentation Switched Capacitor
Building Block
DESCRIPTIO
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.
FEATURES
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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
APPLICATIO S
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Precision Instrumentation Amplifiers
Ultra Precision Voltage Inverters, Multipliers
and Dividers
V–F and F–V Converters
Sample-and-Hold
Switched Capacitor Filters
TYPICAL APPLICATIO
5V
4
7
8
Instrumentation Amplifier
140
5V
3
1µF
C
H
11
DIFFERENTIAL
INPUT
C
S
12
1µF
13
14
R1
16
0.01µF
17
LTC1043 • TA01
C
S
= C
H
= 1µF
+
–
8
1
V
OUT
CMRR (dB)
120
100
80
60
40
20
100
1/2 LTC1013
2
4
–5V
1µF
(EXTERNAL)
R2
1/2 LTC1043
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
1k
10k
100k
FREQUENCY OF COMMON MODE SIGNAL
LTC1043 • TA02
–5V
U
U
U
CMRR vs Frequency
1043fa
1
LINER [ LINEAR TECHNOLOGY ]
