19-1840; Rev 0; 10/00 Low-Power Analog Temperature Sensor in SC70 Package Features ♦ Low Current Consumption (10µA max) ♦ Small SC70 Package ♦ Accurate (±1°C max at TA = +25°C) ♦ Optimized to Drive Large Capacitive Loads Ordering Information PART MAX6605MXK-T TEMP. RANGE PIN-PACKAGE -55°C to +125°C 5 SC70-5 ________________________Applications Pin Configuration Cellular Phones Battery Packs TOP VIEW GPS Equipment Digital Cameras VCC 1 A 2 5 GND 4 B MAX6605 OUT 3 SC70 Typical Application Circuit VCC VCC VDD B MAX6605 CS = 0.1µF A VCC SHDN MAX1106 OUT GND CPU CONVST I/O REFOUT SCLK I/O REFIN DOUT I/O IN+ 1nF IN– GND GND GND ________________________________________________________________ Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX6605 General Description The MAX6605 precision, low-power, analog output temperature sensor is available in a 5-pin SC70 package. The device has a +2.7V to +5.5V supply voltage range and 10µA supply current over the -55°C to +125°C temperature range. For the -40°C to +105°C temperature range, the supply voltage can go as low as +2.4V. Accuracy is ±1°C at TA = +25°C and ±3°C from 0°C to +70°C. The MAX6605 output voltage is dependent on its die temperature and has a slope of 11.9mV/°C and an offset of 744mV at 0°C. The output typically shows only +0.4°C of nonlinearity over the -20°C to +85°C temperature range. MAX6605 Low-Power Analog Temperature Sensor in SC70 Package ABSOLUTE MAXIMUM RATINGS VCC to GND ..............................................................-0.3V to +6V OUT, A, B to GND ......................................-0.3V to (VCC + 0.3V) ESD Protection (Human Body Model) .............................>2000V Current into Any Pin ............................................................10mA Output Short-Circuit Duration.....................................Continuous Continuous Power Dissipation (TA = +70°C) 5-Pin SC70 (derate 3.1mW/°C above +70°C) ..............245mW Operating Temperature Range .........................-55°C to +125°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C 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. ELECTRICAL CHARACTERISTICS (VCC = +2.7V to +5.5V, CL = 1nF, TA = -55°C to +125°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL Temperature Error VOUT = 0.744 + (0.0119 × T°C) + (1.604 × 10-6 × T2)V (Note 2) Supply Voltage CONDITIONS VCC = +3.3V VCC MIN TYP -1.0 +1.0 TA = -0°C to +70°C -3.0 +3.0 TA = -20°C to +85°C -3.8 +3.8 TA = -40°C to +100°C -5.0 +5.0 TA = -55°C to +125°C -5.8 +5.8 TA = -55°C to +125°C 2.7 5.5 TA = -40°C to +105°C 2.4 5.5 Supply Current IQ No load 4.5 Output Voltage VOUT TA = 0°C 744 Nonlinearity TA = -20°C to +85°C Sensor Gain (Average Slope) TA = -40°C to +100°C 11.1 Required for stability 1 Capacitive Load Load Regulation MAX TA = +25°C 10 µA mV/°C nF TA = -20°C to +125°C, IOUT = -20µA to +20µA 20 TA = -55°C, IOUT = -10µA to +10µA 20 _______________________________________________________________________________________ V °C 12.7 Note 1: All parameters are measured at TA = +25°C. Specifications over temperature range are guaranteed by design. Note 2: Error (expressed in °C) is defined as the difference between the calculated and measured values of output voltage. Guaranteed by design to 5 sigma. 2 °C mV 0.4 11.9 UNITS m°C/µA Low-Power Analog Temperature Sensor in SC70 Package TEMPERATURE ERROR vs. TEMPERATURE 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 -55 -35 -15 5 25 45 65 MAX6605 toc03 2 0 5 25 45 65 0 85 105 125 1 2 3 4 5 SUPPLY VOLTAGE (V) SUPPLY CURRENT vs. TEMPERATURE OUTPUT VOLTAGE vs. SUPPLY VOLTAGE STEP-RESPONSE FROM +25°C TO +100°C (FLUORINERT BATH) 5 VCC = +3.3V 4 VCC = +2.4V 2 1.055 MAX6605 toc06 MAX6605 toc04 1.060 OUTPUT VOLTAGE (V) SUPPLY CURRENT (µA) 3 TEMPERATURE (°C) VCC = +5V 3 TA = +25°C 4 TEMPERATURE (°C) 7 6 5 1 -55 -35 -15 85 105 125 6 MAX6605 toc05 OUTPUT VOLTAGE (V) 1.8 1.7 1.5 1.3 1.1 0.9 0.7 0.5 0.3 0.1 -0.1 -0.3 -0.5 -0.7 -0.9 -1.1 -1.3 SUPPLY CURRENT (µA) 2.0 SUPPLY CURRENT vs. SUPPLY VOLTAGE MAX6605 toc02 2.2 TEMPERATURE ERROR (°C) MAX6605 toc01 OUTPUT VOLTAGE vs. TEMPERATURE 1.050 1.045 OUT 500mV/div 1.040 TA = +25°C 1.035 1.030 1 1.025 0 1.020 -55 -35 -15 5 25 45 65 TEMPERATURE (°C) 85 105 125 0 0 1 2 3 4 5 6 1s/div SUPPLY VOLTAGE (V) _______________________________________________________________________________________ 3 MAX6605 Typical Operating Characteristics (VCC = +3.3V, CS = 0.1µF, CL = 1nF, unless otherwise noted.) Low-Power Analog Temperature Sensor in SC70 Package MAX6605 Pin Description PIN NAME FUNCTION 1 VCC Supply Input. Decouple with a 0.1µF capacitor to GND. 2 A Must be connected to GND. 3 OUT Temperature Sensor Output, CL ≥ 1nF 4 B Must be connected to VCC. 5 GND Ground Detailed Description The MAX6605 analog output temperature sensor’s output voltage is a linear function of its die temperature. The slope of the output voltage is 11.9mV/°C, and there is a 744mV offset at 0°C to allow measurement of negative temperatures. The MAX6605 has three terminals: VCC, GND, and OUT. The maximum supply current is 10µA, and the supply voltage range is from +2.4V to +5.5V for the -40°C to +105°C temperature range and +2.7V to +5.5V for the -55°C to +125°C temperature range. The temperature error is <1°C at TA = +25°C, <3.8°C from TA = -20°C to +85°C, and <5.8°C from TA = -55°C to +125°C. Nonlinearity The benefit of silicon analog temperature sensors over thermistors is linearity over extended temperatures. The nonlinearity of the MAX6605 is typically 0.4°C over the -20°C to +85°C temperature range. Transfer Function The temperature-to-voltage transfer function has an approximately linear positive slope and can be described by the equation: Applications Information Sensing Circuit Board and Ambient Temperatures Temperature sensor ICs like the MAX6605 that sense their own die temperatures must be mounted on, or close to, the object whose temperature they are intended to measure. Because there is a good thermal path between the SC70 package’s metal leads and the IC die, the MAX6605 can accurately measure the temperature of the circuit board to which it is soldered. If the sensor is intended to measure the temperature of a heatgenerating component on the circuit board, it should be mounted as close as possible to that component and should share supply and ground traces (if they are not noisy) with that component where possible. This will maximize the heat transfer from the component to the sensor. The thermal path between the plastic package and the die is not as good as the path through the leads, so the MAX6605, like all temperature sensors in plastic packages, is less sensitive to the temperature of the surrounding air than it is to the temperature of its leads. It can be successfully used to sense ambient temperature if the circuit board is designed to track the ambient temperature. As with any IC, the wiring and circuits must be kept insulated and dry to avoid leakage and corrosion, especially if the part will be operated at cold temperatures where condensation can occur. The thermal resistance junction to ambient (θJA) is the parameter used to calculate the rise of a device junction temperature (TJ) due to its power dissipation. For the MAX6605, use the following equation to calculate the rise in die temperature: TJ = TA + θJA ((VCC × IQ) + (VCC - VOUT) IOUT) T (°C) = (VOUT - 744mV) / 11.9mV/°C The MAX6605 is a very-low-power temperature sensor and is intended to drive very light loads. As a result, the temperature rise due to power dissipation on the die is insignificant under normal conditions. For example, assume that the MAX6605 is operating from a +3V supply at +21.6°C (VOUT = 1V) and is driving a 100kΩ load (IOUT = 10µA). In the 5-pin SC70 package, the die temperature will increase above the ambient by: To account for the small amount of curvature in the transfer function, use the equation below to obtain a more accurate temperature reading: TJ - TA = θJA ((VCC × IQ) + (VCC - VOUT) IOUT) = 324°C/W × ((3V × 10µA) + (3V - 1V) × 10µA) = 0.0162°C VOUT = 0.744V + 0.0119V/°C ✕ T(°C) + Therefore, the error caused by power dissipation will be negligible. VOUT = 744mV + (T ✕ 11.9mV/°C) where T is the MAX6605’s die temperature in °C. Therefore: 1.604 ✕ 10-6 mV/°C2 ✕ (T(°C))2 4 _______________________________________________________________________________________ Low-Power Analog Temperature Sensor in SC70 Package TRANSISTOR COUNT: 573 SC70, 5L.EPS Package Information Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600_____________________ 5 © 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX6605 Chip Information Capacitive Loads The MAX6605 can drive unlimited load capacitance. For stable operation load capacitance should be >1nF.