MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
The address PWMCTRL consists of control bits for configuring the PWM/SDA pin:
Bit 0
Bit 1
Bit 2
Select the type of 1 - Single PWM, factory default for
0 – Extended PWM, factory default
for MLX90614xBx
0 - Disable PWM (Enable SMBus),
Factory default
PWM mode:
Enable/disable
the PWM:
MLX90614xAx
1 - Enable PWM, disable SMBus
Configuration of
the pin PWM:
Mode selection
Extemded PWM
definition
1 - Push-Pull,
0 – OpenDrain NMOS, factory default
Bit 3
Bits[8:4]
1 - ThermoRelay,
0 - PWM, Factory default
Number of repetitions divided by 2 of sensor 1 and 2 in Extended PWM
mode. The number of repetitions can vary from 0 to 64 times.
2MHz divided by the number written in this place. (128 in case the number is
0.) A single PWM period consists of 2048 clocks and extended PWM of 4096
clocks for each period (2T in figure 6). The 2 MHz clock is valid for the
nominal HFO frequency.
Bits[15:9] PWM clock
configuration
The address ConfigRegister1 consists of control bits for configuring the analog and digital parts:
Bits[2:0]
– Configure coefficients of IIR
digital filter:
Bit 2
Bit 1
Bit 0
a1
b1
0
1
1
1
1
x
1
1
0
0
x
1
0
1
0
0.5
0.5
0.571428571
0.666(6)
0.428571428
0.333(3)
0.8
1
0.2
0 (IIR bypassed)
Bit 3
– Configure the type of
1 - PTC,
0 – PTAT.
ambient temperature sensor:
– Configure the type of data
transmitted through PWM:
Bits[5:4]
Bit 5
Bit 4
Data 1
Ta
Ta
IR 1
IR 2
Data 2
IR 1
IR 2
IR 2
Undefined*
0
0
1
1
0
1
1
0
Bit 6
– Define the number of IR
sensors:
1 – 2 sensors,
0 -1 sensor.
Bit 7
– Define the sign Ks
(Ks=dAlpha/dTobj) :
– Configure coefficient N of
FIR digital filter:
Factory calibration, do not alter
Bits[10:8]
Bit 10 Bit 9
Bit 8
N
8**
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
16**
32**
64**
128
256
512
1024
Bits[13:11] – Configure the gain of
amplifier:
Bit 13 Bit 12 Bit 11
Gain
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1 (preamplifier bypassed)
3
6
12.5
25
50
100
100
Bit 14
Bit 15
Unused
– Define the sign of thermo-
shock compensation:
1 - negative,
0 – positive.
Note: The following bits/registers should not be altered (except with special tools – contact Melexis for such
tools availability) in order to keep the factory calibration relevant:
Ke [15..0] ; Config Register1 [13..11;7;3] ; addresses 00Fh and 019h.
* not recommended for extended PWM mode
** note recommended values
3901090614
Rev 003
Page 12 of 40
Data Sheet
03/Oct/2007
MELEXIS [ Melexis Microelectronic Systems ]
