MLX90614_15 Datasheet, PDF (41/51 Pages) Melexis Microelectronic Systems – Single and Dual Zone Infra Red Thermometer in TO-39

MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
The MLX90614 can be configured in EEPROM to operate as a thermal relay. A non contact freezing or
boiling prevention with 1 mA quiescent current can be built with two components only – the MLX90614 and a
capacitor. The PWM / SDA pin can be programmed as a push-pull or open drain NMOS, which can trigger an
external device, such as a relay (refer to electrical specifications for load capability), buzzer, RF transmitter or a
LED. This feature allows very simple thermostats to be built without the need of any MCU and zero design
overhead required for firmware development. In conjunction with a MCU, this function can operate as a system
alert that wakes up the MCU. Both object temperature and sensor die temperature can also be read in this
configuration.
11.5 High voltage source operation
As a standard, the module MLX90614Axx works with a supply voltage of 5Volt. In addition, thanks to
the integrated internal reference regulator available at pin SCL / Vz, this module can easily be powered from
higher voltage source (like VDD=8…16V). Only a few external components as depicted in the diagram below
are required to achieve this.
J1
V+
PWM
GND
CON1
R1
Q1
C*
1 MLX90614
SCL
U1
Vz
PWM
2 ^SDA
Vss ⁴
Vdd
3
C1
2.2uF
+12V
Q1
+5V
R1
U1
5.7V
Equivalent schematics
Figure 40: 12V regulator implementation
With the second (synthesized Zener diode) function of the SCL / Vz pin used, the 2-wire interface
function is available only if the voltage regulator is overdriven (5V regulated power is forced to Vdd pin).
3901090614
Rev 009
Page 41 of 52
Data Sheet
June 29, 2015