EVB90614 Melexis Inc, EVB90614 Datasheet - Page 25

• Manufacturer Part Number: EVB90614
• Description: BOARD EVAL FOR MLX90614
• Manufacturer: Melexis Inc

Specifications of EVB90614

• Sensor Type: Temperature
• Sensing Range: -40°C ~ 125°C
• Interface: SMBus (2-Wire/I²C)
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: MLX90614
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Sensitivity: -

8.6 Switching Between PWM and SMBus communication
8.6.1 PWM is enabled
The diagram below illustrates the way of switching to SMBus if PWM is enabled (factory programmed POR
default for MLX90614 is SMBus, PWM disabled). Note that the SCL pin needs to be kept high in order to use
PWM.
8.6.2 Request condition
If PWM is enabled, the MLX90614’s SMBus Request condition is needed to disable PWM and reconfigure
PWM/SDA pin before starting SMBus communication. Once PWM is disabled, it can be only enabled by
switching the supply OFF – ON or exit from Sleep Mode. The MLX90614’s SMBus request condition requires
forcing LOW the SCL pin for period longer than the request time (t
ignored in this case.
8.6.3 PWM is disabled
If PWM is disabled by means of EEPROM the PWM/SDA pin is directly used for the SMBus purposes after
POR. Request condition should not be sent in this case.
3901090614
Rev 006
SCL
PWM/SDA
PWM mode
t
REQ
>1.44ms
Figure 17: Switching from PWM mode to SMBus
Figure 18: Request (switch to SMBus) condition
SCL
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SMBus Request
t
REQ
Infra Red Thermometer in TO-39
>1,44ms
SMBus mode
REQ
) >1,44ms. The SDA line value is
Single and Dual Zone
September 30, 2010
Data Sheet
Stop