FM75_06 FAIRCHILD [Fairchild Semiconductor], FM75_06 Datasheet
FM75_06
Related parts for FM75_06
FM75_06 Summary of contents
Page 1
FM75 Low-Voltage Two-Wire Digital Temperature Sensor with Thermal Alarm Features ■ User Configurable 12-bit Resolution ■ Precision Calibrated to ±1°C, 0°C to 100°C Typical ■ Temperature Range: -40°C to 125°C ■ Low Operating Current (less ...
Page 2
Pin Assignments Pin Descriptions Pin # Name 1 SDA 2 SCL GND A0, A1 © 2006 Fairchild Semiconductor Corporation FM75 Rev. 1.0.8 SDA 1 8 SCL 2 7 FM75 OS ...
Page 3
Absolute Maximum Ratings The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not ...
Page 4
Logic Electrical Characteristics Symbol Parameter V Minimum Input Voltage IH Logic HIGH V Maximum Input Voltage IL Logic LOW V Maximum Output Voltage OL Logic LOW I Quiescent Supply Current DD I Shutdown Current DD-SD I Input Leakage Current IN ...
Page 5
Serial Port Timing Symbol Parameter t SCL Clock Period SCL SCL Clock Transition Time T:LH T:HL t SCL Clock LOW Period LOW t SCL Clock HIGH Period HIGH t Bus free time between a Stop and BUF ...
Page 6
Basic Operation The FM75 temperature sensing circuitry continuously produces analog voltage proportional to the device tem- perature. At regular intervals, the FM75 converts the analog voltage to a two’s complement digital value, which is placed into the temperature register. The ...
Page 7
Comparator Mode In comparator mode, each time a temperature-to-digital (T-to-D) temperature conversion occurs, the new digital temperature is compared to the value stored in the T and T registers fault tolerance number of con- HYST secutive temperature measurements ...
Page 8
Registers The FM75 contains the following five registers: ■ Command Register ■ Temperature Register ■ Configuration Register ■ Over-Limit-Signal Temperature Register (T ■ Hysteresis Temperature Register ( Serial Interface Command Register 1-byte Write Only Command Register The command ...
Page 9
Temperature Register The temperature register is a two-byte (16-bit) read-only register. Digital temperatures from the T-to-D converter are stored in the temperature register in two’s comple- ment format and the contents of this register are updated at regular intervals, each ...
Page 10
Over-Limit Signal Temperature Register (T The T register is a two-byte (16-bit) read/write register OS that stores the user-programmable upper trip-point tem- perature for the thermal alarm in two’s-complement for- mat. At power-up, this register defaults to 80°C (i.e. 0101 ...
Page 11
Serial Data Bus Operation General Operation Writing to and reading from the FM75 registers is accom- plished via the SMBus-compatible two-wire serial inter- face. SMBus protocol requires that one device on the bus initiates and controls all read and write ...
Page 12
Reading If the pointer is already pointing to the desired register, the master can read from that register by setting the read/write bit (following the slave address one. After sending an ACK, the FM75 begins transmitting data dur- ...
Page 13
Timing Diagrams SCL SDA Address Byte . . . SCL SDA . . . Repeat Start Address Byte from Master Figure 11. Pointer Set Followed by Immediate ...
Page 14
Timing Diagrams (Continued) SCL SDA Address Byte . . . . . . . . A Figure 14. Pointer Set Followed by Immediate Write to A 2-byte Register (T SCL ...
Page 15
Mechanical Dimensions Dimensions are in inches (millimeters) unless otherwise noted. Figure 17. Molded Package, Small Outline, 0.15 Wide, 8-Lead (M8) © 2006 Fairchild Semiconductor Corporation FM75 Rev. 1.0.8 15 www.fairchildsemi.com ...
Page 16
Fairchild Semiconductor Corporation FM75 Rev. 1.0.8 16 www.fairchildsemi.com ...