aSM121 SIMISTOR™ TEMPERATURE SENSOR ULTRA-LOW-POWER SILICON THERMISTOR PRODUCT SPECIFICATION New Release Specification General Description Pin Configuration The aSM121 is a high-precision, 3-lead CMOS silicon thermistor in an ultra-small leadless package that provides a cost-effective solution for applications requiring highaccuracy low-power temperature monitoring. The aSM121 functions in a way that is similar to a PTC thermistor. However, it is linear-calibrated, enabling application developers to directly interpret output voltage as temperature without complex compensation for nonlinearity. QFN-3 1 VDD 3 GND aSM121 The aSM121 output voltage ramp has a positive slope of 10mV/°C that is independent of supply voltage. The aSM121 has a guaranteed room temperature (25°C) accuracy of ±1°C. The aSM121 does not require external calibration - each device is calibrated at the factory. 2 VOUT Top view, contacts underneath, actual part marking below Features • • • Precision Calibrated to ±1°C at 25°C Temperature Range: -30°C to 125°C Extremely Linear Output Ramp: 10mV/°C • • 0°C Output: 0.50V Output Ramp is Calibrated to Degrees Celsius • • Low Operating Current: 14μA Operating Voltage Range: +2.7 V to +3.6V • • Non-linearity: ≤ 0.8°C 1.2mm x 1.5mm QFN Package Accuracy vs Temperature 4 • Mobile Phones • Mobile Communications Terminals • Computers • Battery Management • FAX Machines/Printers/Copiers • Portable Medical Instruments • HVAC, Power Supply Modules • Disk Drives • Automotive Control Circuits Accuracy (°C) 3 Applications 2 1 upper spec limits 0 lower spec limits --1 --2 --3 -4 -40 -20 0 25 20 125 40 60 80 100 120 Temperature (°C) Ordering Information Part Number Package Temperature Range Part Marking How Supplied aSM121Q3 3-Lead QFN -30˚C to +125˚C Jm 3000 units on T&R m – month / year code © Andigilog, Inc. 2004 www.andigilog.com July 2005 - 70A04006 aSM121 Absolute Maximum Ratings1 Parameter Rating Supply Voltage +7V Output Voltage VDD + 0.5V Continuous Current, any terminal 10mA Storage Temperature Range -60°C to +150°C ESD2 Human Body Model 4000V Machine Model 400V QFN-3 TBD Thermal Resistance - ΘJA Lead Temp Notes: 1. Absolute maximum ratings are limits beyond which operation may cause permanent damage to the device. These are stress ratings only; functional operations at or above these limits is not implied. 2. Human Body Model: 100pF capacitor discharged through a 1.5kΩ resistor into each pin. Machine Model: 200pF capacitor discharged directly into each pin. 3. These specifications are guaranteed only for the test conditions listed. 260°C Recommended Operating Ratings Symbol Parameter Min Max Units VDD Supply Voltage +2.7 +3.6 V VOUT Output Voltage 0 1.8 V TA Operating Temperature Range -30 +125 °C Electrical Characteristics3 Limits apply for -40°C ≤ T A ≤ +125°C and V D D = + 3 .0V unless otherwise noted. Parameter Symbol 4 Accuracy Conditions Min Typ Max Units TA=+25°C TA=-30°C (TMIN) TA=+125°C (TMAX) -1 ±0.5 +1 °C -4 ±1 +4 °C -3 ±1 +3 °C 5 Non-linearity ±0.8 Supply Current - Output floating 6 Output Sink Capability 6 Output Source Capability Average Output Slope (Sensor Gain) IDD TA=+25°C -30°C ≤ T A ≤ +125°C IOL +2.7V < VDD < +3.6V IOH +2.7V < VDD < +3.6V AOUT °C 14 15 — μA 25 μA 200 μA 10 mV/°C Zero-Degree Output Voltage VOUT0 TA=+0°C 500 mV Room Temp Output Voltage VOUT25 TA=+25°C 750 mV QFN-3 0.025 °C 7 Self Heating Notes: 4. Accuracy (expressed in °C) = Difference between calculated output voltage and measured output voltage. Calculated output voltage = 10mV/°C multiplied by device’s case temperature at specified conditions of temperature, voltage and power supply with an offset of 500mV (see Fig. 1). 5. Non-linearity is defined as the deviation of the output-voltage-versus-temperature curve from the best-fit straight line, over the device’s rated temperature range. 6. Lowest output current should be targeted; higher currents result in more self-heating of the device. 7. Max Self Heating = ΘJA x (VDD x IDD). Assumes a capacitive load. © Andigilog, Inc. 2004 -2www.andigilog.com July 2005 - 70A04006 aSM121 VOUT (mV) 1750 1500 1350 900 750 500 300 200 -30 0 25 50 75 100 125 Temperature (ºC) Temp (ºC) = (VOUT – 500mV) / 10mV/ºC) Figure 1. aSM121 Output Voltage vs. Temperature Mounting The aSM121 package provides good thermal conductivity to the surface to which it is soldered. It’s low mass allows it to respond quickly to changes in board temperature. In this case, its temperature will be within about 0.02°C of the temperature of the surface it is attached to if the ambient air temperature is almost the same as the surface temperature. If the air temperature is much higher or lower than the surface temperature, the actual temperature of the aSM121 die will be at an intermediate temperature between the surface temperature and the air temperature. To ensure good thermal conductivity, the backside of the aSM121 die is directly attached to the GND pin. The lands and traces to the aSM121 will, of course, be part of the printed circuit board, which is the object © Andigilog, Inc. 2004 whose temperature is being measured. These printed circuit board lands and traces will not cause the aSM121’s temperature to deviate from the desired temperature. Alternatively, the aSM121 can be mounted inside a sealed-end metal tube, and can then be dipped into a bath or screwed into a threaded hole in a tank. As with any IC, the aSM121 and accompanying wiring and circuits must be kept insulated and dry to avoid leakage and corrosion. This is especially true if the circuit may operate at cold temperatures where condensation can occur. Printed-circuit coatings and varnishes such as Humiseal and epoxy paint or dips can be used to ensure that moisture cannot corrode the aSM121 or its connections. -3www.andigilog.com July 2005 - 70A04006 aSM121 Typical Performance Characteristics 16 15 14 13 IDD (µA) 12 11 10 9 8 V DD =+3V 7 -50 -25 0 25 5 50 0 75 100 125 Temperature (°C) Figure 2. aSM121 Current vs Temperature Typical Applications 3.3V 3.9K aSM121 VTemp IN Serial REF Analog-to-Digital Converter 1.75V U1 FB 10K U3 + 100K SERIAL DATA OUT Adjustable Shunt Voltage Reference CLOCK U2 ENABLE Figure 3. Serial Output Temperature to Digital Converter (Full Scale = +125˚C) © Andigilog, Inc. 2004 -4www.andigilog.com July 2005 - 70A04006 aSM121 Typical Applications (cont.) 3.3V 15K 8 IN aSM121 U1 Parallel Output Analog-to-Digital Converter _ U2 5K PARALLEL DATA OUTPUT 1.75V + VREF INTR U3 CS 15K RD WR Figure 4. Parallel Output Temperature to Digital Converter (Full Scale = +125˚C) 3.3 R3 R4 R1 2.5V Shunt Voltage Reference U3 VT + U1 0.1μF VOUT – R2 3.3 aSM121 VTemp U2 Figure 5. Thermostat / Fan Controller © Andigilog, Inc. 2004 -5www.andigilog.com July 2005 - 70A04006 aSM121 QFN-3 Package Dimensions and PC Layout Pattern 0.2 mm + 0.10 -0.0 Ref. Package Outline 0.2 mm + 0.10 -0.0 0.350 ± 0.050 0.350 ± 0.050 Pin 1 Dot Marking 0.203 ± 0.025 0.500 ± 0.050 2-PL 1.000 ± 0.050 Exposed Pad 0.5 mm + 0.10 -0.0 0.5 mm + 0.10 -0.0 1 QFN 3L 0.6 mm + 0.10 -0.0 1.1 mm + 0.10 -0.0 PC Layout Pattern (1.2mm x 1.5mm) 1.000 ± 0.050 1.500 ± 0.050 3 2 0.200 ± 0.050 0.2 mm + 0.10 -0.0 1.200 ± 0.050 1.050 ± 0.050 Top View 0.200 ± 0.050 0.250 ± 0.050 0.000 ± 0.050 0.750 ± 0.025 Bottom View Side View Note: Solder mask is recommended to be 0.07mm larger than PC lands. Figure 6. Package Outline Tape and Reel Data 2.00 ± 0.05 4.00 ± 0.10 Æ 1.50 + 0.10 4.00 ± 0.10 1.75 ± 0.10 8.00 + 0.30 - 0.10 3.50 ± 0.05 SEC - AA SEC - BB Æ 1.00 + 0.25 0.254 ± 0.013 SEC - AA SEC - BB 10 MAX 1.35 ± 0.10 1.02 ± 0.10 10 MAX 1.75 ± 0.10 Part Orientation Figure 7. Tape Dimensions and Part Orientation © Andigilog, Inc. 2004 -6www.andigilog.com July 2005 - 70A04006 aSM121 Data Sheet Classifications Preliminary Specification This classification is shown on the heading of each page of a specification for products that are either under development(design and qualification), or in the formative planning stages. Andigilog reserves the right to change or discontinue these products without notice. New Release Specification This classification is shown on the heading of the first page only of a specification for products that are either under the later stages of development(characterization and qualification), or in the early weeks of release to production. Andigilog reserves the right to change the specification and information for these products without notice. Fully Released Specification Fully released datasheets do not contain any classification in the first page header. These documents contain specification on products that are in full production. Andigilog will not change any guaranteed limits without written notice to the customers. Obsolete datasheets that were written prior to January 1, 2001 without any header classification information should be considered as obsolete and non-active specifications, or in the best case as Preliminary Specifications. Andigilog, Inc. 8380 S. Kyrene Rd., Suite 101 Tempe, Arizona 85284-2120 Tel: (480) 940-6200 Fax: (480) 940-4255 © Andigilog, Inc. 2004 -7www.andigilog.com July 2005 - 70A04006 aSM121 Notes: Andigilog, Inc. 8380 S. Kyrene Rd., Suite 101 Tempe, Arizona 85284-2120 Tel: (480) 940-6200 Fax: (480) 940-4255 © Andigilog, Inc. 2004 -8www.andigilog.com July 2005 - 70A04006