EL8170FSZ-T7A Ver la hoja de datos (PDF) - Intersil

Número de pieza

componentes Descripción

Fabricante

EL8170FSZ-T7A

Micropower, Single Supply, Rail-to-Rail Input-Output Instrumentation Amplifiers

Intersil 

EL8170, EL8173

.

VIN/2

VIN/2

VCM

VREF

RG

+2.4V TO +5.5V

71

3 IN+

V+

+

2 IN-

- EL8170,

6

8 FB+ EL8173

+

5 FB-

- V-

4

RF

VOUT

FIGURE 39. REFERENCE CONNECTION WITH AN AVAILABLE VREF

VOUT

=

⎛

⎜1

⎝

+

R-R----G-F--⎠⎟⎞

(

VIN

)

+

(

VREF

)

(EQ. 3)

External Resistor Mismatches

Because of the independent pair of feedback terminals provided

by the EL8170 and EL8173, the CMRR is not degraded by any

resistor mismatches. Hence, unlike a three op amp and

especially a two op amp in-amp, the EL8170 and EL8173 reduce

the cost of external components by allowing the use of 1% or

more tolerance resistors without sacrificing CMRR performance.

The EL8170 and EL8173 CMRR is maintained regardless of the

tolerance of the resistors used.

Gain Error and Accuracy

The EL8173 has a Gain Error, EG, of 0.2% typical. The EL8170 has

an EG of 0.3% typical. The gain error indicated in the “Electrical

Specifications” table on page 2 is the inherent gain error of the

EL8170 and EL8173 and does not include the gain error

contributed by the resistors. There is an additional gain error due

to the tolerance of the resistors used. The resulting non-ideal

transfer function effectively becomes Equation 4:

VOUT

=

⎛

⎜1

⎝

+

R-R----G-F--⎠⎟⎞

× [1 – (ERG + ERF + EG)] × VIN

(EQ. 4)

Where:

ERG = Tolerance of RG

ERF = Tolerance of RF

EG = Gain Error of the EL8170 or EL8173

The term [1 - (ERG + ERF + EG)] is the deviation from the

theoretical gain. Thus, (ERG + ERF + EG) is the total gain error. For

example, if 1% resistors are used for the EL8170, the total gain

error would be as shown in Equation 5:

= ±(ERG + ERF + EG(typical))

= ±(0.01 + 0.01 + 0.003)

= ±2.3%

(EQ. 5)

Power Dissipation

It is possible to exceed the +150°C maximum junction

temperatures under certain load and power-supply conditions. It

is therefore important to calculate the maximum junction

temperature (TJMAX) for all applications to determine if power

supply voltages, load conditions, or package type need to be

modified to remain in the safe operating area. These parameters

are related in Equation 6:

TJMAX = TMAX + (θJAxPDMAXTOTAL)

(EQ. 6)

where:

• PDMAXTOTAL is the sum of the maximum power dissipation of

each amplifier in the package (PDMAX)

• PDMAX for each amplifier can be calculated as shown in

Equation 7:

PDMAX

=

2*VS × ISMAX + (VS

-

VO

UT

MAX

)

×

V-----O----U----T----M-----A----X--

RL

(EQ. 7)

where:

• TMAX = Maximum ambient temperature

• θJA = Thermal resistance of the package

• PDMAX = Maximum power dissipation of 1 amplifier

• VS = Supply voltage (Magnitude of V+ and V-)

• IMAX = Maximum supply current of 1 amplifier

• VOUTMAX = Maximum output voltage swing of the application

• RL = Load resistance

For additional products, see www.intersil.com/en/products.html

Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted

in the quality certifications found at www.intersil.com/en/support/qualandreliability.html

Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time

without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be

accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third

parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.

For information regarding Intersil Corporation and its products, see www.intersil.com

12

FN7490.7

October 15, 2013

Share Link: