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Freescale Semiconductor, Inc.

5

MPL115A2

Shutdown

For longer periods of inactivity the user may assert the SHDN input by driving this pin low to reduce system power consumption.

This removes power from all internal circuits, including any registers. In the shutdown state, the Pressure and Temperature

registers will be reset, losing any previous ADC output values.

Characteristics Table), after which another pressure reading can be taken by transitioning to the data Conversion step.

For values with less than 16 bits, the lower LSBs are zero. For example, c12 is 14 bits and is stored into 2 bytes as follows:

3.1

Pressure, Temperature and Coefficient Bit-Width Specifications

The table below specifies the initial coefficient bit-width specifications for the compensation algorithm and the specifications for

Pressure and Temperature ADC values.

Table 2. Device Memory Map

Address

Name

Description

Size (bits)

0x00

Padc_MSB

10-bit Pressure ADC output value MSB

8

0x01

Padc_LSB

10-bit Pressure ADC output value LSB

2

0x02

Tadc_MSB

10-bit Temperature ADC output value MSB

8

0x03

Tacd_LSB

10-bit Temperature ADC output value LSB

2

0x04

a0_MSB

a0 coefficient MSB

8

0x05

a0_LSB

a0 coefficient LSB

8

0x06

b1_MSB

b1 coefficient MSB

8

0x07

b1_LSB

b1 coefficient LSB

8

0x08

b2_MSB

b2 coefficient MSB

8

0x09

b2_LSB

b2 coefficient LSB

8

0x0A

c12_MSB

c12 coefficient MSB

8

0x0B

c12_LSB

c12 coefficient LSB

8

0x0C

Reserved*

—

—

0x0D

Reserved*

—

—

0x0E

Reserved*

—

—

0x0F

Reserved*

—

—

0x10

Reserved

—

—

0x11

Reserved

—

—

0x12

CONVERT

Start Pressure and Temperature Conversion

—

*These registers are set to 0x00. These are reserved, and were previously utilized as Coefficient values, c11 and

c22, which were always 0x00.

Pressure, Temperature and Compensation Coefficient Specifications

a0

b1

b2

c12

Padc

Tadc

Total Bits

16

16

16

14

10

10

Sign Bits

1

1

1

1

0

0

Integer Bits

12

2

1

0

10

10

Fractional Bits

3

13

14

13

0

0

dec pt zero pad

0

0

0

9

0

0