NXP Semiconductors

MPL115A2S

Miniature I2C digital barometer, 50 kPa to 115 kPa

8.3 Evaluation sequence, arithmetic circuits

The following is an example of the calculation for Pcomp, the compensated pressure output. Input values are in

bold.

c12x2 =

c12 * Tadc

a1 =

b1 + c12x2

a1x1 = a1 *

Padc

y1 =

a0 + a1x1

a2x2 =

b2 * Tadc

Pcomp = y1 + a2x2

This can be calculated as a succession of Multiply Accumulates (MACs) operations of the form y = a + b * x:

aaa-044109

a

y

+

b

X

x

The polynomial can be evaluated (Equation 1) as a sequence of 3 MACs:

b1

c12

Tadc

a1

a0

Padc

y1

b2

PComp

Tadc

y

aaa-044110

Refer to NXP application note AN3785 for more detailed notes on implementation.

8.4 I2C device read/write operations

All device read/write operations are memory mapped. Device actions, for example, Start Conversions, are

controlled by writing to the appropriate memory address location.

• For I2C, the 7-bit device address (from Table 2) has a read/write toggle bit, where the least significant bit is ‘1’

for read operations or ‘0’ for write operations. The Device Address is C0h for a Write and the Device Address

is C1h for a Read.

MPL115A2S

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Product data sheet

Rev. 1.3 — 17 May 2024

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