Part: MLX90614 — Melexis

Type: Infra Red Thermometer

Description: Non-contact Infra Red thermometer with integrated thermopile detector and signal conditioning, factory calibrated for sensor temperatures from -40°C to +125°C and object temperatures from -70°C to +380°C, offering 0.5°C accuracy and 0.02°C measurement resolution.

Operating Conditions:

• Supply voltage: 3V or 5V nominal
• Sensor operating temperature: -40 to +85 °C (suffix-dependent — see Ordering Information for grade-specific ranges)
• Object temperature range: -70 to +380 °C

Key Specs:

• Standard accuracy: ±0.5 °C (0°C to +50°C for Ta and To)
• Medical accuracy: ±0.2 °C (in a limited range around human body temperature)
• Measurement resolution: 0.02 °C
• SMBus output resolution: 0.02 °C
• PWM output resolution: 0.14 °C (for -20°C to 120°C range)
• Calibrated emissivity: 1 (customizable 0.1 to 1.0)
• Optical filter pass band: 5.5–14 μm

Features:

• Small size, low cost, easy to integrate
• Factory calibrated in wide temperature range
• Single and dual zone versions
• SMBus compatible digital interface
• Customizable PWM output for continuous reading or thermal relay
• Sleep mode for reduced power consumption
• Automotive grade

Applications:

• High precision non-contact temperature measurements
• Thermal Comfort sensor for Mobile Air Conditioning control system
• Temperature sensing element for residential, commercial and industrial building air conditioning
• Windshield defogging
• Automotive blind angle detection
• Industrial temperature control of moving parts
• Home appliances with temperature control
• Healthcare
• Body temperature measurement

Package:

• TO-39

• Small size, low cost
• Easy to integrate
• Factory calibrated in wide temperature range:
• -40°C…+125˚C for sensor temperature and -70°C…+380˚C for object temperature.
• High accuracy of 0.5°C in a wide temperature range (0°C…+50°C for both Ta and To)
• High (medical) accuracy calibration
• Measurement resolution of 0.02°C
• Single and dual zone versions
• SMBus compatible digital interface
• Customizable PWM output for continuous reading
• Available in 3V and 5V versions
• Simple adaptation for 8V…16V applications
• Sleep mode for reduced power consumption
• Different package options for applications and measurements versatility
• Automotive grade

MLX90614ESF-BAA-000-TU Pinout

Package: TO-39 (4-pin)

Notes

• MLX90614ESF-BAA-000-TU is a 5V single-zone IR thermometer (ESF = TO-39 package, A = 5V supply, A = single zone, 000 = standard part, TU = tape/reel packing).
• Pin 1 (SCL/Vz): In SMBus mode, acts as serial clock input. The integrated 5.7V zener can be used to supply the device from external 8…16V sources via external transistor circuit.
• Pin 2 (SDA/PWM): Dual-function pin. Factory default is SMBus mode (open-drain NMOS); can be configured for PWM thermal relay output.
• Metal can is electrically connected to VSS (Pin 4); no separate electrical connection to the can is recommended for EMC and isothermal reasons.
• Schmidt trigger input is automatically enabled on SCL and SDA pins when operated in 2-wire interface mode.

Table 1: Absolute maximum ratings for MLX90614

Exceeding the absolute maximum ratings may cause permanent damage.

Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

The MLX90614 can be configured as a thermo relay with programmable threshold and hysteresis on the PWM/SDA pin. The input for the comparator unit of the relay is the object temperature from sensor 1

The output of the MLX90614 is NOT a relay driver but a logical output which should be connected to a relay driver if necessary.

The output driver is one and the same for PWM and Thermal relay. In order to configure the MLX90614 to work as thermal relay two conditions must be met:

• o Set bit TRPWMB high at address 0x02 in EEPROM
• o Enable PWM output i.e. EN_PWM is set high

The PWM / SDA pin can be programmed as a push-pull or open drain NMOS (via bit PPODB in EEPROM PWMCTRL), which can trigger an external device. The temperature threshold data is determined by EEPROM at address 0x21 (Tomin) and the hysteresis at address 0x020 (Tomax).

The logical state of the PWM/SDA pin is as follows:

PWM / SDA pin is high if hysteresis threshold TO + ≥ 1

PWM / SDA pin is low if hysteresis threshold TO -≤ 1

Figure 21: Thermal relay: 'PWM' pin versus Tobj

Single and Dual Zone Infra Red Thermometer in TO-39

The MLX90614 preserves its normal operation when configured as a thermal relay (PWM configuration and specification applies as a general rule also for the thermal relay) and therefore it can be read using the SMBus (entering the SMBus mode from both PWM and thermal relay configuration is the same).

For example, the MLX90614 can generate a wake-up alert for a system upon reaching a certain temperature and then be read as a thermometer. Reset conditions (enter and exit Sleep, for example) will be needed in order to return to the thermal relay configuration.