Data Sheet

©2008, 2010-2011 CADEKA Microcircuits LLC

www.cadeka.com

12

Pressure Measurement Applications

The CLC1200 is especially suitable for higher resistance

pressure sensors powered at lower voltages where small

size and low power become more significant.

Figure 3 shows a 3kΩ pressure transducer bridge

powered from 5V. In such a circuit, the bridge consumes

only 1.7mA. Adding the CLC1200 and a buffered voltage

divider allows the signal to be conditioned for only 3.8mA

of total supply current.

Small size and low cost make the CLC1200 especially

attractive for voltage output pressure transducers.

Since it delivers low noise and drift, it will also serve

applications such as diagnostic noninvasive blood pressure

measurement.

Medical ECG

The CLC1200 is perfect for ECG monitors because of

its low current noise. A typical applicaiton is shown in

Figure 4. The CLC1200’s low power, low supply voltage

requirements, and space-saving 8-lead SOIC package

offerings make it an excellent choice for battery-powered

data recorders.

Furthermore, the low bias currents and low current noise,

coupled with the low voltage noise of the CLC1200,

improve the dynamic range for better performance.

The value of capacitor C1 is chosen to maintain stability

of the right leg drive loop. Proper safeguards, such as

isolation, must be added to this circuit to protect the

patient from possible harm.

CLC1200

+

_

Ref

499

G = 100

3k

5V

3k

3k

3k

1.7mA

IN

AGND

Digital

Data

Output

CLCxxx

+

_

1.3mA

5V

5V

20k

10k

20k

0.1mA

REF

5V

CLC1200

G = 7

+

_

8.25k

R1

10k

G = 143

0.03Hz

High-Pass

Filter

CLCxxx

+

_

3V

Output

1V/mV

R3

24.9k

R2

24.9k

C1

R4

1M

-3V

Patient

Figure 3: Pressure Monitoring Circuits Operating on a Single 5V Supply

Figure 4: Typical Circuit for ECG Monitor Applications