MLX90601C Datasheet SPI IR thermometer module Features • • • • • • Remote temperature measurement Fully linearised signals 125kb/s SPI Factory calibrated EEprom ECC Open drain relay driver output Applications • • • • Automotive climate control Toasters, microwave ovens and other appliances that require temperature control Residential, commercial climate control and occupancy detection Industrial temperature transducer and monitoring applications Ordering Information M L X 9 0 6 0 1 E Z A Temperature Suffix Product Code C Type X X Version Package Suffix Supply, i/o-Configuration and temperature ranges Part No MLX90601 MLX90601 Suffix Package ZA ZA Temperature E E Type C C Version AA BA B Analog voltage output C SPI serial interface D PWM output Description digital SPI –20/120°C 5V supply digital SPI 5/60°C 5V supply Description Functional Diagram IR+ IRRsens VSS VDD 5V IRINP C2 C3 IRINN TEMPOUT TEMPOUT TINP R1 IROUT IROUT TINN MLX90247 C4 R2 MLX90313 CS SCLK SDI SDO REL1 CREF VSS VREFP C5 CS SCLK DIN DOUT REL VREF VSS/GND R3 390109060103 Rev. 004 The MLX90601C is a versatile IR thermometer module, which performs signal conditioning, linearisation and ambient temperature compensation. The module is built around the MLX90313 IR amplifier-interface, which uses high performance, chopper stabilized amplifiers, providing excellent noise performance. The sensing element is the MLX90247 discrete IR thermopile. The module is delivered factory calibrated. The SPI offers both the sensor ambient temperature and the object temperature in 12 bit digital form. Additionally the module offers several analog pins for access to the programmable comparator circuitry and the reference voltage. Page 1 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module ELECTRICAL CHARACTERISTICS Parameter Symbol Regulator and consumption Supply voltage range Vin Supply current Idd POR threshold voltage Vpor IR-chain amplifier and output driver Power supply rejection PSSR ratio Input referred white noise Vnir Chopper frequency fc Output voltage range Output source current Iod Output sink current Ios DC Output impedance, rod drive DC Output impedance, ros sink Amplifier bandwidth BW Temp-chain amplifier and output driver Power supply rejection PSSR ratio Input referred white noise Vntemp Chopper frequency fc Output voltage range ORtemp Output source current Iod Output sink current Ios AC Output impedance ro Amplifier bandwidth BW Rel1 open drain relay driver High voltage protections output impedance Ro ADC Monotonicity Differential non-linearity DNL Integral non-linearity INL Gain error Total input-referred noise DAC Resolution Monotonicity Differential non-linearity DNL Integral non-linearity INL PWM PWM Clock period Tclk PWM Total period T Leading buffer time t1 Trailing buffer time t5 Duty cycle high t2 Duty cycle low t3 Error signal t4 Rise time* 390109060103 Rev. 004 Test Condition Min Typ Max Unit VDD @ Ta=25°C 4.5 5 5 1.3 6 5.6 1.5 V mA V 1.1 f ≤ 100kHz 75 dB rms-value 25 10 nV/√Hz kHz V mA uA Ω 100 Ω 8 IROUT IROUT IROUT IROUT 0 1 20 Vdd-0.2 IROUT 500 f ≤ 100kHz Hz 75 dB rms-value 400 500 nV/√Hz kHz V mA uA Ω Hz 10 V Ω 15 TEMPOUT TEMPOUT TEMPOUT TEMPOUT 0 1 20 Vdd-0.2 100 32 guaranteed by design 0.4 LSB ½ LSB 1 LSB 0.2 LSB full scale Vref=3V 8 bit guaranteed by design ½ LSB ½ LSB 45 92.16 % of T % of T % of T % of T % of T 10% to 90% of Vh Page 2 of 12 50 102.4 12.5 12.5 0 0 55 112.64 50 50 25 13.3 100 µs ms % % % % % µs Dec/01 MLX90601C Datasheet SPI IR thermometer module Parameter Fall time* Output voltage high Output voltage low *Without external loading Symbol Vh Vl Test Condition General Description Typ 13.3 4 Max Unit 100 µs V V 1 Absolute Maximum Ratings MLX90601 is a versatile IR thermometer built around the MLX90247 Discrete IR thermopile sensor with on-chip PTC and the MLX90313 Programmable IR sensor interface. MLX90313 amplifies the signals coming from MLX90247 and converts them to digital by means of two high performance, low noise, chopper stabilized amplifiers and the 12-bit analog to digital converter. The digital unit on the interface then performs the ambient compensation of the IR signal. This results in two temperature signals, one representing the temperature of the object the IR sensor is pointed at (Tobject) and one representing the temperature of the sensor (Tambient). Both signals are then linearised and stored in dedicated registers, which are accessible through SPI (Tobject at register address 09h, Tambient at register address 0Ah). The REL1 output is directly connected to the open drain relay driver output of the comparator circuitry inside MLX90313. The TEMPOUT pin is connected to a pseudo push-pull output stage of the second comparator. Both comparators can act on the linearised object or ambient temperature and have programmable hysteresis values and polarity settings. Supply Voltage, VDD (overvoltage) 80V Supply Voltage, VDD (operating) 4.5V - 6V Reverse Voltage Protection -5V Supply Current, IDD @25°C 6 mA Output Current, IOUT mA Operating Temperature Range, TA -40°C - 125°C Storage Temperature Range, TS -55°C - 150°C ESD Susceptibility 4kV Pinout Unique Features MLX90601 is an automotive grade IR thermometer that can be fitted to any contactless temperature measurement application by means of the programmable Interfaces. The module is designed to cope with all standard qualification tests oriented towards the harsh automotive environment. If so desired, all temperature ranges and comparator settings can be adapted to the application. MLX90601 is delivered calibrated, relieving the customer of IR calibration. 390109060103 Rev. 004 Min 90% to 10% of Vh Ihigh=2mA Ilow=2mA Pin 1 Symbol REL1 2 3 4 5 6 7 8 9 10 VSS VDD SDIN SDOUT CSB SCLK IROUT VREF TEMPOUT Description Open drain, relay driver comparator output Ground Supply pin SPI data input SPI data output SPI chip select input SPI clock input Object temperature output Reference voltage Ambient temperature output Detailed Description Analog Features Supply The module should be supplied directly with a nominal 5V regulated supply on pin VDD. (4.5V – 6V) The power-on reset circuitry is completely internal to MLX90313. The module is fully operational 16 ms from the time the supply Page 3 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module crosses 1.3V. The POR circuit will issue another reset if the supply voltage goes below 1.3V. In the second step the value of the ambient temperature is combined with the measured signal coming from the IR thermopile sensor inside MLX90247 to obtain a calculated value for the object temperature, based on the calibration data. The value is stored in a dedicated register and also available for the output electronics and SPI. A/D The MLX90313 on the module contains a 12-bit internal analog to digital converter. Real 12-bit conversion is achieved by a fully differential analog part of the converter. Automatic calibration is implemented in the background, which allows precise conversion in a very wide temperature range. Sensor Characteristics For detailed specification we refer to the datasheet on MLX90247, available from the Melexis website. In a calibrated module the linearisation unit of MLX90313 takes all characteristics of the sensor into account, including all process variations they are subject to. Comparators Two comparator circuits are available. Comparator 1 drives the Rel1 open drain output and is triggered by the linearised object temperature signal. The threshold level is programmed in the eeprom. Comparator 2 drives the TEMPOUT pin and is triggered by the linearised object temperature signal. The threshold level is programmed in EEPROM and can be changed through the SPI. Configuration and settings for the comparators are accessible through the SPI. For details please refer to the application note on the SPI. The TO-39 sensor housing of the thermopile has a 2.5mm diameter aperture, resulting in a 70° full angle field of view. The silicon filter used as IR-window is treated with an antireflective coating that will pass minimum 75% of IR radiation in the wave length band from 7.5µm to 13.5µm. Below 5µm, 99.5% of incoming radiation is reflected by the filter Linearisation Unit Serial Peripheral Interface (SPI) The linearisation unit of MLX90313 realizes 3 functions: 1. Offset measurement and calibration (offset drift compensation) 2. Measurement and offset cancellation 3. Linearisation. Linearisation proceeds in two steps. In the first step the ambient temperature is calculated from the measured signal coming from the on-chip PTC temperature sensor of MLX90247. The value is stored in a dedicated register than is available for the output electronics. Protocol The digital interface implemented in MLX90313C is SPI compatible. It can be used to access the on-chip EEPROM and all internal registers. The chip will always work as a slave device. The format of any command is always 32 bits: 8 bits for the operation code, 8 bits for the address and 16 bits of data. The communication protocol is presented below. CS SCLK SDI C7 C6 C5 C4 C3 C2 C1 C0 X SDO A7 A6 A5 A4 A3 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X C7 C6 C5 C4 C3 C2 C1 C0 A7 A6 A5 A4 A3 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8 X D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X write command CS SCLK SDI C7 SDO C6 C5 C4 C3 C2 C1 X C0 A7 A6 A5 A4 A3 A2 A1 A0 X C7 C6 C5 C4 C3 C2 C1 C0 D15 D14 D13 read command 390109060103 Rev. 004 Page 4 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module Every write command starts with a high to low transition of CS and ends by a low to high transition of CS after 32 periods of the serial data clock (SCLK). MLX90313C reads the data present on SDI on the rising edge of the clock. With a delay of 8 periods of the serial clock, the SPI will repeat the opcode, address and the first 8 bits of data on pin SDO. This allows the external master to check command and address and terminate the operation in case of an error by forcing CS high before the end of the complete command cycle, i.e. before the end of the 32 clock periods. The read command is build up similarly, except that no data has to be passed of course. On SDO the opcode will be followed directly by the tcls requested data, the address is not returned in this case. The data on SDO is valid on the rising edge of the clock. In case of a read command, the SPI th will output the data on SDO starting on the 25 rising edge of the clock (after CS low) as indicated in the figure above. Timing/speed The baud-rate depends on the serial data clock (SCLK) supplied by the master controller and is limited to 125kb/s. The timing requirements are given in the figure and table below tsclk tsch CS SCLK tsu thd SDI tdv SDO Symbol tsclk tcls tsch tsu thd tdv SPI timing requirements Parameter Value Sclk period min 8 CS low to SCLK high min 50 SCLK low to CS high min 50 data in setup time min 200 data in hold time min 200 data out valid min 1 Unit µs ns ns ns ns µs operation codes The operation code is the first series of 8bits in a command, C[7:0] in the figure on the protocol above. 390109060103 Rev. 004 Below table summarizes the operations available in MLX90313C. mnem. WR RD WEPR ER REPR BLWR BLER Operation Codes Command X101X0XX Write internal register X10010XX Read internal register 0001XXXX Write EEprom 001XXXXX Erase EEprom X0001XXX Read EEprom 1001XXXX Block Write EEprom 101XXXXX Block erase EEprom C[7:0] Additional information on the SPI and use can be found in the application note on SPI. Page 5 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module CSB: Pin Descriptions Active low, chip select pin for the SPI. Communication is started on the falling edge of CS and ended on the rising edge of CS. REL1 Open drain relay driver output. The typical onresistance of this driver is <10Ω with a supply voltage of VDD=5V. The default configuration of comparator 1 is shown in the figure below. REL1 Tobject SCLK: Serial data clock from the external master to be supplied to this pin. Maximum frequency is 125kHz. COMP Threshold in EEPROM IROUT VSS Hysteresis in EEPROM The comparator is a digital comparator, with a resolution of 12 bits. By default the input polarity is inverting. By default the trigger temperature is the object temperature but also the ambient (sensor) temperature can be used. Threshold and hysteresis values are version dependent, as indicated below. default REL1 settings Version Threshold Hysteresis 5/60°C version 45°C ±2°C -20/120°C version 95°C ±5°C In the default setting of the module, this pin is IR PWM coded temperature output. The driver can source or sink at least 2mA to/from an external load. It is possible to change the function of this pin by means of the SPI. By setting the appropriate values in the EEPROM configuration registers the pin can be used as analog output. For details on how to do this, please refer to the application note on the SPI. The details on the functionality of the IROUT pin in analog and PWM mode are covered in the datasheets on MLX90601B and MLX90601D respectively. VREF VDD: Supply pin Voltage reference I/O pin. This level is by default dependent on the on-chip band-gap reference and can be programmed in the range 2-4.5V in EEprom configuration registers. The default setting is 4.5V. This voltage is used as reference for ADC, DAC (analog outputs). The 90313 can be configured to use an external reference (2-5V) instead of the on-chip bandgap, if required. SDIN: TEMPOUT Serial data input pin for the SPI. Data is accepted on the rising edge of the serial data clock (SCLK) In the default setting of the module, this pin is used as output for comparator2. The driver can source or sink at least 2mA to/from an external load. The default configuration of comparator 2 is shown in the figure below. It is possible to change the configuration and settings of the comparator through the SPI. VSS: Supply pin DOUT: Serial data output pin for the SPI. Data is valid on the rising edge of the serial data clock (SCLK) 390109060103 Rev. 004 Page 6 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module analog options Tambient or Tobject Tempout COMP Threshold in EEPROM Hysteresis in EEPROM The comparator is a digital comparator, with a resolution of 12 bits. By default the input polarity is inverting. The default threshold and hysteresis values are version dependent, as indicated below. 390109060103 Rev. 004 default Comparator 2 settings Version Threshold Hysteresis 5/60°C version 45°C ±2°C -20/120°C version 95°C ±5°C It is possible to change the configuration and settings of the comparator through the SPI. It is possible to change the function of the TEMPOUT pin by means of the SPI. By setting the appropriate values in the EEPROM configuration registers the pin can be used as analog output or PWM output for the ambient temperature. For details on how to do this, please refer to the application note on the SPI. The details on the functionality of the TEMPOUT pin in analog and PWM mode is covered in the datasheets on MLX90601B and MLX90601D respectively. Page 7 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module Applications Information Connection of the MLX90601 module into an application is straightforward. The 5V regulated supply should be connected between pin 3 (VDD) and pin 5 (VSS). There are numerous possibilities for the I/O of which one typical example is shown below. Here the default configuration is used. In the example a relay is switched with the REL1 output. The threshold for this comparator is programmed in the eeprom. This means the micro controller can change the threshold, and the MLX90601 can control the alarm standalone. The second comparator drives the TEMPOUT pin. The SPI connection to the host microcontroller can be a permanent connection in the application or just a means for in-circuit programming of the device. Through this connection full access to the internal registers and configuration settings is achieved. The SPI connection can also be used to directly read output data from the module in digital form and process this directly in the application. An interesting feature is in-circuit programming of the calibration constants. It is possible to change the range or emissivity, or whatever setting needs to be user selectable. IR sensor IR+ MLX90313 IRINP REL1 To Thermisto r IR- IRINN Rsens TINP VSS TINN OPA 1 SW1 A/D D/A COMP Digital OPA SW2 A/D D/A To MLX90247 12 COMP VCM25V CREF TEMPOUT 10 VREFP 9 VDD 3 Vref 5V 2 Control and Support Blocks VSS alarm VSS SPI MLX90601C SPI 4 5 6 7 Micro-controller I/O-port 390109060103 Rev. 004 Page 8 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module ESD Precautions Electronic semiconductor products are sensitive to Electro Static Discharge (ESD). Always observe Electro Static Discharge control procedures whenever handling semiconductor products. FAQ Q: What is the accuracy? A: For an object temperature range between 5°C and 60°C the accuracy of measurement is ±1°C. For the wider object temperature range version (-20°C/120°C) the accuracy of measurement is ±2°C. Q: What is FOV? A: The FOV or Field Of View is a definition of the area the sensor is ‘seeing’. The sensor will detect radiation coming in at an angle, relative to the sensor’s central axis, from 0° to 35°C. The full viewing angle is thus 70°. Q: What is the useful temperature range? A: There are two temperature ranges of interest; the temperature of the object (or target), which you are trying to measure and the temperature of the sensor. The sensor temperature, called Tambient, should be between 0°C and 50°C. Outside this range the ambient temperature compensation will no longer work and calculation of the object’s temperature will no longer be correct. The TEMPOUT output will saturate under this condition. The object temperature, called Tobject, should be between 5°C and 60°C. Outside this range the IROUT output will saturate. Q: Can the temperature ranges be changed? A: Yes, MLX90313 is a programmable device. Melexis selected a limited set of standard ranges that will fit the majority of applications in order to limit delivery times. However, if necessary, the ranges can be adapted for any particular application. Glossary of Terms ADC: Analog to Digital Converter Ambient Compensation: The IR signal captured by a thermopile sensor is not only dependent 390109060103 Rev. 004 on the temperature of the object (Tobject) but also on the temperature of the sensor itself. Therefore the IR signal is compensated for this effect by means of the measured sensor temperature (Tambient). This rather complex calculation is performed in the linearisation unit of MLX90313. Chopper Amplifier: Special amplifier configuration aimed at ultra low offset. DAC: Digital to Analog Converter. EEprom: Non-volatile memory that can be electrically erased and rewritten. This type of memory is used to store configuration and calibration data for the module. ECC: Error Checking and Correction. The EEprom on board of MLX90313 is equipped with a checking and correction feature based on the Hamming Code method. IR: Infrared. Every object emits infrared radiation in relation to its temperature. This effect can be used to measure this temperature without the need for physical contact. Linearisation: The signal from a thermopile is not linear with the object temperature. MLX90313 is therefore equipped with a digital calculation unit that produces an output that is linear with the object temperature. POR: Power-on reset: Reset circuit that starts the digital system in a known state whenever the supply voltage is cycled PSSR: Power Supply Rejection Ratio: Measure for an amplifier’s immunity to disturbances on the supply connection. PTC: See Thermistor PWM: Pulse Width Modulation: Binary periodical signal which uses variation of the duty cycle to code information. SPI: Serial Peripheral Interface. Commonly used, 4 wire, serial link to connect different circuits over a short distance Ta, Tambient: The temperature of the IR sensor. Target: or Object: The object the IR module is aimed at. Thermistor: Temperature dependant resistor. Basically there are 2 types. The types that increase their resistance with rising temperature are PTC (positive thermal coefficient) type. The ones that decrease their resistance with rising temperature we call NTC (negative thermal coefficient) type. The MLX90313 can work with both types. The MLX90601 modules are equipped with sensors that use PTCs. To, Tobject: The temperature of the object one wished to measure with the module Page 9 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module Disclaimer Melexis reserves the right to periodically make modifications to product specifications. The information included herein is believed to be 390109060103 Rev. 004 accurate and reliable. However, Melexis assumes no responsibility for its use; nor for any infringements of patents or other rights of third parties, which may result from its use. Melexis Page 10 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module Physical Characteristics 390109060103 Rev. 004 Page 11 of 12 Dec/01 MLX90601C Datasheet SPI IR thermometer module Future mechanical design on flex board The mechanical outline of the MLX90601 module will change due to a transition from a rigid FR-4 substrate to a polyimide flexible film. Below drawing shows the future outline and pinning of the module For the latest version of this document, go to our website at: www.melexis.com Or for additional information contact Melexis Direct: Europe and Japan: Phone: +32 13 61 16 31 E-mail: [email protected] 390109060103 Rev. 004 All other locations: Phone: +1 603 223 2362 E-mail: [email protected] Page 12 of 12 Dec/01