MLX90615

Infra Red Thermometer

3901090615

Page 10 of 32

Data Sheet

Rev 005

08 November 2013

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Config register bit meaning (0x02)

0

- Comminucation type is PWM

1

- Comminucation type is SMBus

0

- PWM frequency = 1KHz

1

- PWM frequency = 10KHz

0

- PWM output = To

1

- PWM output = Ta

- 0…63 - Internal RC oscillator trimnming

- MLXreserved - DO NOT alter

0

0

- GAIN = 1 - Amplifier bypassed

MLX reserved - DO NOT alter

0

1

- GAIN = 10

MLX reserved - DO NOT alter

1

0

- GAIN = 40

MLX reserved - DO NOT alter

1

1

- GAIN = 40

MLX reserved - DO NOT alter

0

- Internal shunt regulatior disabled

1

- Internal shunt regulatior enabled

0

0

0

- FORBIDDEN COMBINATION

0

0

1

- IIR (2) a1=1, b1=0

0

1

0

- IIR (3) a1=0.5, b1=0.5

0

1

1

- IIR (4) a1=0.333(3), b1=0.666(6)

1

0

0

- IIR (5) a1=0.25, b1=0.75

1

0

1

- IIR (6) a1=0.2, b1=0.8

1

1

0

- IIR (7) a1=0.166(6), b1=0.833(3)

1

1

1

- IIR (8) a1=0.14286, b1=0.87514

0

MLX reserved - DO NOT alter

Table 7 Config register meaning of the MLX90615 (continued)

*Note: IIR setting 000b must be avoided

Emissivity

: Contains the value for object emissivity correction. The MLX90615 will compensate for the

emissivity of the object measured with respect to that value. The equation for that register is

(

)

(

)

ε

×

=

16384

2

round

hex

dec

Emissivity

Where

( )

(

)

x

round

hex

dec2

represents decimal to hexadecimal conversion with round-off to nearest

factor in IR measurements refer to the FAQ section of the current document.

Factory default is 0x4000, which sets the thermometer to an emissivity of 1.0 (emissivity correction is off).

8.3.4 RAM

RAM can be read through SMBus interface. Limited numbers of RAM registers, summarized below

are of interest to the customer.

RAM (16x16)

Name

Address

Read access

Melexis reserved

0x00

Yes

…

…

…

Melexis reserved

0x04

Yes

Raw IR data

0x05

Yes

0x06

Yes

0x07

Yes

Melexis reserved

0x08

Yes

…

…

…

Melexis reserved

0x0F

Yes

Table 8 RAM address list of the MLX90615

scale is 0.02°K/LSB. To convert a read object temperature into degrees Celsius the equation is:

[ ]

(

)

15

.

273

02

.

0

07

0

−

×

=

°

x

RAM

C

T

O

Raw IR data is in sign (1 bit, the MSB) and magnitude (15 bits) format.