MAX30205
15Pages

Human Body Temperature Sensor General Description The MAX30205 temperature sensor accurately measures temperature and provide an overtemperature alarm/ interrupt/shutdown output. This device converts the temperature measurements to digital form using a highresolution, sigma-delta, analog-to-digital converter (ADC). Accuracy meets clinical thermometry specification of the ASTM E1112 when soldered on the final PCB. Communication is through an I2C-compatible, 2-wire serial interface. The I2C serial interface accepts standard write byte, read byte, send byte, and receive byte commands to read the temperature data and configure the behavior of the opendrain overtemperature shutdown output. The MAX30205 features three address select lines with a total of 32 available addresses. The sensor has a 2.7V to 3.3V supply voltage range, low 600µA supply current, and a lockup-protected I2C-compatible interface that make it ideal for wearable fitness and medical applications. ●● High Accuracy and Low-Voltage Operation Aids Designers in Meeting Error and Power Budgets • 0.1°C Accuracy (37°C to 39°C) • 16-Bit (0.00390625°C) Temperature Resolution • 2.7V to 3.3V Supply Voltage Range ●● One-Shot and Shutdown Modes Help Reduce Power Usage ●● 600μA (typ) Operating Supply Current ●● Digital Functions Make Integration Easier into Any System • Selectable Timeout Prevents Bus Lockup • Separate Open-Drain OS Output Operates as Interrupt or Comparator/Thermostat Output This device is available in an 8-pin TDFN package and operates over the 0NC to +50NC temperature range. Applications ●● Fitness ●● Medical Ordering Information appears at end of data sheet. Typical Application Circuit +2.7V TO +3.3V

Human Body Temperature Sensor Absolute Maximum Ratings Note 1: Human Body Model, 100pF discharged through a 1.5kI resistor. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Recommended Operating Conditions (TA = 0°C to +50°C, unless otherwise noted.)...

Human Body Temperature Sensor Electrical Characteristics (continued) (VDD = 2.7V to 3.3V, TA = 0°C to +50°C, unless otherwise noted. Typical values are VDD = 3.0V, TA = +25NC.) (Note 3) PARAMETER Quiescent Supply Current Shutdown mode, inactive, TA = 0°C to +50°C Depends on fault queue setting Factory default setting THYST Default Temperature Factory default setting Input-High Leakage Current Input-Low Leakage Current Input Capacitance Output-High Leakage Current OS Output Saturation Voltage I2C AC Electrical Characteristics (VDD = 2.7V to 3.3V, TA = 0°C to +50°C, unless otherwise noted....

Human Body Temperature Sensor I2C AC ELECTRICAL CHARACTERISTICS (continued) (VDD = 2.7V to 3.3V, TA = 0°C to +50°C, unless otherwise noted. Typical values are VDD = 3.0V, TA = +25°C.) (Notes 3, 6) (Figure 1) PARAMETER Pulse Width of Suppressed Spike Transmit SDA Fall Time SDA Time Low for Reset of Serial Interface Note 3: Limits are 100% production tested at TA = +25NC. Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed. Note 4: All voltages are referenced to ground. Currents entering...

Human Body Temperature Sensor Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) STATIC QUIESCENT SUPPLY CURRENT vs. TEMPERATURE (SHUTDOWN MODE) STATIC QUIESCENT SUPPLY CURRENT vs. TEMPERATURE toc01 MEAN ERROR MEAN ERROR MEAN ERROR Maxim Integra

Human Body Temperature Sensor Serial-Data Input/Output Line. Open-drain. Connect SDA to a pullup resistor. High impedance for supply voltages from 0 to 3.3V. Serial-Data Clock Input. Open-drain. Connect SCL to a pullup resistor. High impedance for supply voltages from 0 to 3.3V. Overtemperature Shutdown Output. Open-drain. Connect OS to a pullup resistor. I2C Slave Address Input. Connect A2 to GND or VDD to set the desired I2C bus address. Do not leave unconnected (Table 1). I2C Slave Address Input. Connect A1 to GND, VDD, SDA, or SCL to set the desired I2C bus address. Do not leave...

Human Body Temperature Sensor Block Diagram DIGITAL LOGIC BLOCK TOS REGISTER TEMP REGISTER DIGITAL COMPARATOR THYST REGISTER THERMOSTAT LOGIC I2C BLOCK DATA POINTER FAULT QUEUE BITS DATA REGISTER BLOCK D1 D0 0 LSB FAULT FAULT ONE DATA OS COMPARATOR/ 1 CONFIG TIMEOUT SHUTDOWN QUEUE QUEUE SHOT FORMAT [1] [2] POLARITY INTERRUPT MS BYTE TEMPERATURE CORE BLOCK DIGITAL CONTROL VOLTAGE REFERENCE TEMPERATURE SENSOR

Human Body Temperature Sensor Detailed Description The MAX30205 temperature sensor measures temperature and converts the data into digital form. An I2C-compatible two-wire serial interface allows access to conversion results. The device accepts standard I2C commands to read the data, set the overtemperature alarm (OS) trip thresholds, and configure other characteristics. While reading the temperature register, any changes in temperature are ignored until the read is completed. The temperature register is updated for the new temperature measurement upon completion of the read operation. OS...

Human Body Temperature Sensor Table 1. MAX30205 Slave Address Selection SLAVE A2 A1 A0 ADDRESS CONNECTION CONNECTION CONNECTION BYTE (hex) GND In interrupt mode, exceeding TOS also asserts OS. OS remains asserted until a read operation is performed on any of the registers. Once OS has asserted due to crossing above TOS and is then reset, it is asserted again only when the temperature drops below THYST. The output then remains asserted until it is reset by a read. It is then asserted again if the temperature rises above TOS, and so on. Putting the MAX30205 into shutdown mode also resets OS....