mlx90614 Melexis Company, mlx90614 Datasheet - Page 30

• Manufacturer Part Number: mlx90614
• Description: Single And Dual Zone Infra Red Thermometer In To-39
• Manufacturer: Melexis Company

11 Applications Information
11.1 Use of the MLX90614 thermometer in SMBus configuration
Connection of the MLX90614 to SMBus with 3.3V power supply. The MLX90614 has diode clamps SDA/SCL
to Vdd so it is necessary to provide MLX90614 with power in order not to load the SMBus lines.
11.2 Use of multiple MLX90614s in SMBus configuration
The MLX90614 supports a 7-bit slave address in EEPROM, thus allowing up to 127 devices to be read via
two common wires. With the MLX90614BBx this results in 254 object temperatures measured remotely and
an additional 127 ambient temperatures which are also available. Current source pull-ups may be preferred
with higher capacitive loading on the bus (C3 and C4 represent the lines’ parasitics), while simple resistive
pull-ups provide the obvious low cost advantage.
3901090614
Rev 003
C1
0.1uF
C2
0.1uF
3
3
U1
U1
Vdd
Vdd
Figure 23: Use of multiple MLX90614 devices in SMBus network
PW M
SDA
PW M
SDA
2
2
Vss
Vss
4
4
SCL
Vz
SCL
Vz
MLX90614Bxx
MLX90614Bxx
C1
0.1uF
1
1
3
U2
Figure 22: MLX90614 SMBus connection
Vdd
P W M
SDA
2
Vss
4
I1
Ipu1
Current source or resistor
pull-ups of the bus
SCL
Vz
MLX90614Bxx
1
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R1
I2
Ipu2
R2
SMBus
+3.3V
Infra Red Thermometer in TO-39
SDA
Vdd
SDA
SCL
GND
R1
MLX90614 family
U1
SCL
R2
Cbus2
Cbus1
SMBus
C4
C3
+3.3V
MCU
Single and Dual Zone
Vdd
SDA
SCL
GND
U1
MCU
Data Sheet
03/Oct/2007