Rev.. LOW-VOLTAGE C-MOS HIGH-PRECISION TEMPERATURE SENSOR IC The is a high-precision temperature sensor IC that outputs voltage with a temperature coefficient of -8.5mV/ C and a temperature accuracy of ±.5 C. A temperature sensor, a constant current circuit and an operational amplifier are integrated on a single chip to be able to operate at.4v. The operating temperature ranges from -40 C to +00 C. The is superior in linearity over conventional temperature sensors like thermistors. It can be applied to an ever expanding wide range of applications that call for high-precision thermal control. Features Block Diagram Temperature accuracy : ±.5 C ( -0 C to +00 C) Linear : -8.5mV/ C Ta = - 0 C :.8 V typ. Ta = +0 C :.6 V typ. Ta = + 00 C : 0.78 V typ. Nonlinearity : ± 0.5 % typ. ( -0 C to +80 C ) Vss standard output Low voltage operation : Vdd min. =.4 V Low current consumption : Idd typ. = 4.5µA ( +5 C) Small plastic package ( SOT- ) + V dd V out Temperature sensor V ss Pin Assignment SOT -. Vss. Vout. Vdd ( Top view ) Seiko Instruments Inc.
LOW-VOLTAGE C-MOS HIGH-PRECISION TEMPERATURE SENSOR IC Absolute Maximum Ratings Item Symbol Ratings Unit Power supply voltage Vdd 6.5 V (Vss=0.0V) voltage Vout Vss to Vdd V Operating temperature Topr -40 to +00 C Storage temperature Tstg -55 to +5 C Electrical characteristics ( - 40 C Ta +00 C, Vdd=5V) Item Symbol Condition Min. Typ. Max. Unit Power supply voltage Vdd.4 6.0 V (Vss=0.0V) Ta = - 0 C.80.8.844 V voltage Vout Ta = + 0 C.05.6.47 V Ta = + 00 C 0.697 0.78 0.79 V Temperature sensitivity Vse - 0 Ta + 00 C - 8.78-8.50-8. mv/ C Nonlinearity NL - 0 Ta + 80 C ± 0.5 % Operating temperature Topr - 40 + 00 V Current consumption Idd Ta = + 5 C 4.5 0.0 µa Seiko Instruments Inc.
LOW-VOLTAGE C-MOS HIGH-PRECISION TEMPERATURE SENSOR Definition of terms. voltage ( Vout ) voltage Vout is defined as the voltage between measured pin- and Vss. Vout is linearly proportional to ambient temperature. is tested for Vout at -0 C,+0 C and +00 C. voltage Vout min. max.. Temperature sensitivity ( Vse ) Temperature sensitivity Vse is defined as the average slope of the Vout versus Ta curve using the following formula. Vse = {Vout(+00) - Vout(-0)} 0 Vout(+00) : voltage at Ta=+00 C Vout( - 0) : voltage at Ta= - 0 C -0 C 0 C +0 C +00 C Ambient temperature Ta voltage Vout Vout(-0) slope : Temperature sensitivity Vout(+00) -0 C 0 C +0 C +00 C Ambient temperature Ta. Nonlinearity NL Nonlinearity NL is defined as the deviation of the Vout versus Ta curve from the best-fit straight line over the device s rated temperature range. NL = a b 00 a : The maximum deviation of the Vout vs. Ta curve from the best-fit straight line between - 0 C and +80 C. b : The difference of the output voltage between - 0 C and +80 C. b a 0 C voltage Vout Vout(-0) a Vout(+80) Vout vs. Ta curve 0 C +80 C Ambient temperature Ta a Best-fit straight line Seiko Instruments Inc.
LOW-VOLTAGE C-MOS HIGH-PRECISION TEMPERATURE SENSOR Load conditions Load capacitance : CL 00p F Load resistance : RL 500k Ω (Note : Do NOT connect a pull-up resistor to Vout pin.) pin- C L 00 p F R L 500 k Ω V out C L R L Seiko Instruments Inc. 4
LOW-VOLTAGE C-MOS HIGH-PRECISION TEMPERATURE SENSOR Typical performance characteristics 000 800 600 400 00 000 800 Ambient temperature (Ta) - voltage (Vout) TYP MIN MAX 600-40 -0 0 0 40 60 80 00 Temperature Ta [ C] Ambient Temperature Ta - Ta [ C] 6 5 4 Accuracy - Temperature 0 - - - -4-5 -6-40 -0 0 0 40 60 80 00 Ambient temperature Ta [ C] TYP MAX MIN Current consumption Idd[µA] 0 9 8 7 6 5 4 Ambient Temperature (Ta) - Current consumption (Idd typ.) 0-40 -0 0 0 40 60 80 00 Ambient temperature Ta [ C] 400 00 00 00 000 900 800 700 600 Typical heat response from 5 C air into 00 C air 0 0 60 90 0 50 80 Time [sec] 95 Power supply voltage (Vdd) - voltage (Vout typ.) Ta=-40 C 4 Power supply voltage (Vdd) - voltage (Vout typ.) Ta=+0 C 94 4 9 9 40 9 9 8 90 74 7 7 7 70 79 4 5 6 Power supply voltage Vdd [V] Power supply voltage (Vdd) - voltage (Vout typ.) Ta=+00 C 4 5 6 Power supply voltage Vdd [V] 7 0 9 8 7 6 5 4 0 4 5 6 Power supply voltage Vdd [V] [ u] Power supply voltage (Vdd) - Current consumption (Idd typ.) Ta=+0 C 4 5 6 Power supply voltage Vdd [V] Seiko Instruments Inc. 5
LOW-VOLTAGE C-MOS HIGH-PRECISION TEMPERATURE SENSOR Start up response Ta=5 C, CL=00pF, RL=0MΩ V dd ( = 6V ) V/div GND V out V/div GND 50 µ sec/div Ta=5 C, CL=00pF, RL=0MΩ V dd ( =.4V ) V/div GND V out V/div GND 50 µ sec/div Seiko Instruments Inc. 6
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