Set Next Test Temperature:

• Calibrate offset and FSO using the ODAC and

FSODAC, respectively.

• Store calibration data in the test computer or

MAX1455 EEPROM user memory.

• Calculate the correction coefficients.

• Download correction coefficients to EEPROM.

• Perform a final test.

Sensor Calibration and

Compensation Example

The MAX1455 temperature compensation design cor-

rects both sensor and IC temperature errors. This enables

the MAX1455 to provide temperature compensation

approaching the inherent repeatability of the sensor. An

example of the MAX1455’s capabilities is shown in Figure

8. Table 16 lists the effects of compensation.

A MAX1455 and a repeatable piezoresistive sensor with

an initial offset of 16.4mV and a span of 55.8mV were

converted into a compensated transducer with an offset of

Figure 7. Comparison of an Uncalibrated Sensor and a Calibrated Transducer

Table 16. Effects of Compensation

TYPICAL UNCOMPENSATED INPUT (SENSOR)

TYPICAL COMPENSATED TRANSDUCER OUTPUT

Offset.....................................................................±100% FSO

FSO ..............................................................1mV/V to 40mV/V

Offset TC ...................................................................20% FSO

Offset TC Nonlinearity .................................................4% FSO

FSOTC .....................................................................-20% FSO

FSOTC Nonlinearity ....................................................5% FSO

Temperature Range........................................-40°C to +125°C

Offset at +25°C.................................................0.500V ±200µV

FSO at +25°C...................................................4.000V ±200µV

Offset Accuracy over Temp. Range ........... ±4mV (±0.1% FSO)

FSO Accuracy over Temp. Range ............. ±4mV (±0.1% FSO)

MAX1455

MODULE 1

DATA

DATA

TEST OVEN

MAX1455

MODULE 2

DIGITAL

MULTIPLEXER

+5V

DIO[1:N]

DIO1

DIO2

DION

MAX1455

MODULE N

DVM

MAX1455

Low-Cost Precision Sensor Signal Conditioner

www.maximintegrated.com

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