NST235-DSTR

NST235  1.5 °C High Precision Ultra-low Current Analog Temperature Sensor Datasheet (EN) 1.2 Product Overview Applications The NST235 is a high precision CMOS analog output temperature sensor. The device offers a maximum accuracy of ±0.5°C at 25°C and a maximum of ±2.5°C over the full temperature range. The device is specified at the full temperature range of -40°C to 150°C and the power supply operating range is 2.3V to 5.5V.  Smartphones The NST235 device provides a positive slope output of  Thermal Protection 10.0mV/°C over -40°C to 100°C. it is highly linear and does not require complex calculations or lookup tables to derive temperature.  Environmental Monitoring and HVAC The NST235 is a low power device, and the typical operating current is 20μA. Therefore, self-heating is negligible. The NST235 is available in SC70(5) and SOT23(3) package, making it suitable for on-board and offline applications in the industrial, and consumer markets applications in the IoT. Device Information  Portable Medical Instruments  Notebook Computers  Industrial Internet of Things (IoT)  Power Supply Modules  Power-system Monitors  Disk Drives Part Number NST235 Package SC70(5) Body Size 2.00mm × 1.25mm SOT-23(3) 2.92mm × 1.30mm Functional Block Diagrams Key Features  High Accuracy Over –40 °C to 150 °C Temperature Range - 0 °C ~ 70°C:  0.5 °C (Typical) - 0 °C ~ 70°C:  1.5 °C (Maximum) - -40 °C ~ 150°C:  2.5 °C (Maximum) VDD VOUT  Operating Voltage Range: 2.3V to 5.5V  Average Sensor Gain o: 10mV/°C  Output Impedance: 1Ω (Typical)  Operating Current: 20μA (Typical)  Push-Pull Output Current Drain: 500µA (Maximum)  Predictable Curvature Error  Output Short Protection GND Figure 1 NST235 Functional Block Diagram  Suitable for Remote Applications  Package: SOT-23(3) and SC70(5) Copyright © 2019, NOVOSENSE Page 1 NST235 Datasheet (EN) 1.2 Index 1 PIN CONFIGURATION AND FUNCTIONS .................................................................................................................................... 3 2 SPECIFICATIONS ......................................................................................................................................................................... 3 2.1 ABSOLUTE MAXIMUM RATINGS ............................................................................................................................................. 3 2.2 ELECTRICAL CHARACTERISTICS ............................................................................................................................................ 4 2.3 TYPICAL CHARACTERISTICS .................................................................................................................................................. 5 3 FUNCTION DESCRIPTION ........................................................................................................................................................... 5 3.1 OVERVIEW .............................................................................................................................................................................. 5 3.2 FUNCTIONAL BLOCK DIAGRAM ............................................................................................................................................. 5 3.3 FEATURE DESCRIPTION ......................................................................................................................................................... 6 3.3.1 NST235 TRANSFER FUNCTION ....................................................................................................................................... 6 3.3.2 APPLICATION CURVE ...................................................................................................................................................... 8 4 APPLICATION INFORMATION ..................................................................................................................................................... 8 4.1 CAPACITIVE LOADS ................................................................................................................................................................ 8 4.2 TYPICAL APPLICATION........................................................................................................................................................... 9 4.3 SYSTEM EXAMPLES ................................................................................................................................................................ 9 4.3.1 CONSERVING POWER DISSIPATION WITH SHUTDOWN ................................................................................................. 9 4.3.2 ANALOG-TO-DIGITAL CONVERTER INPUT STAGE ......................................................................................................... 10 5 PACKAGE INFORMATION .......................................................................................................................................................... 11 5.1 SOT-23(3) PACKAGE ............................................................................................................................................................ 11 5.2 SC70(5) PACKAGE ................................................................................................................................................................ 13 6 ORDER INFORMATION .............................................................................................................................................................. 15 7 REVISION HISTORY ................................................................................................................................................................... 16 Copyright © 2019, NOVOSENSE Page 2 NST235 Datasheet (EN) 1.2 1 Pin Configuration and Functions (Top View) (Top View) Package:5-Pin SC70 Package:3-Pin SOT-23 NC 1 GND 2 VOUT 3 NC 5 VDD 1 3 VDD 4 VOUT GND 2 Figure 1.1 NST235 Pin Configuration Table 1.1 NST235 Pin Function Description Pinout Name Type Description SOT-23 SC70 NC - 1 - GND 3 2 GND VOUT 2 3 Analog output Analog voltage output VDD 1 4 Power Power supply input pin NC - 5 - No Connection Ground pin, connect to power supply negative terminal. This pin must be grounded for optimum thermal conductivity. No Connection, must be floating or connect to grounded 2 Specifications 2.1 Absolute Maximum Ratings Parameters Symbol Min Supply Voltage Pin (VDD) VDD Output Volatge Vout Storage Temperature Operation Temperature TBoperation Max Unit -0.3 6.5 V -0.3 VDD+0.3 V -60 155 °C -40 150 °C 155 °C Maximum Junction Temperature ESD susceptibility Copyright © 2019, NOVOSENSE Typ HBM ±4.5 KV CDM ±500 V Comments Page 3 NST235 Datasheet (EN) 1.2 2.2 Electrical Characteristics at TA = +25°C and VDD = +2.3V to +5.5 V, unless otherwise noted Parameters Symbol Min VDD 2.3 Typ Max Unit 5.5 V Comments Supply Supply Voltage Range Supply Sensitivity 0.1 °C /V Operation Current Iconv 20 μA Shutdown Current ISD 0.1 μA VDD≤0.6V Temperature Range Temperature Range Accuracy (Using equation 3-2) -40 150 °C ±0.5 ±1.5 °C from 0°C to 70°C ±0.5 ±2.5 °C from -40°C to 150°C Output Voltage at 0°C 0.5 V Vout Drive Capability 500 μA Sensor Gain 10 mV/°C Output Impedance 1 Ω Load Regulation 0.5 mV Temperature Coefficient of Quiescent Current -44 nA/°C 0.418 s ±0.2 °C Source ≤50uA Thermal response Stirred Oil Thermal Response Time to 63% of Final Value (Package Only) Drift Drift1 Notes: 1. Drift data is based on a 1000-hour stress test at +130°C with VDD = 5.5V. Copyright © 2019, NOVOSENSE Page 4 NST235 Datasheet (EN) 1.2 2.3 Typical Characteristics at VDD = 3.3 V, unless otherwise noted. Temperature Error(℃) 3.0 2.0 1.0 0.0 -1.0 -2.0 -3.0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Temperature (℃) Figure 2.1 Temperature Error vs Temperature 3 Function Description 3.1 Overview The NST235 is a high precision CMOS analog output temperature sensor. The device offers a maximum accuracy of ± 0.5°C at 25°C and a maximum of ±2.5°C over the full temperature range. The device is specified at the full temperature range of 40°C to 150°C and the power supply operating range is 2.3V to 5.5V. The NST235 device provides a positive slope output of 10.0mV/°C over -40°C to 100°C. it is highly linear and does not require complex calculations or lookup tables to derive temperature. The NST235 is a low power device, and the typical operating current is 20μA. Therefore, self-heating is negligible. The NST235 is available in SC70(5) and SOT-23(3) package, making it suitable for on-board and off-line applications in the industrial, and consumer markets applications in the IoT. 3.2 Functional Block Diagram VDD VOUT GND Figure 3.1 NST235 Functional Block Diagram Copyright © 2019, NOVOSENSE Page 5 NST235 Datasheet (EN) 1.2 3.3 Feature Description 3.3.1 NST235 Transfer Function The NST235 device is linear. However, the output voltage will shift a little when the temperature is greater than 100°C. In order to achieve the highest accuracy performence of the device, we use piecewise linear function to describe the conversion relationship between temperature and output voltage. In the whole working temperature range, the conversion relationship of NST235 is shown in Table 3.2. The parameters of the piecewise linear function used in the three temperature ranges are shown in Table 3.1, and the output voltage is calculated by Equation 3-1: (3-1) VO = TC × (TA − TI ) + VOF Where, VO is the output voltage at a given temperature. TA is the ambient temperature in °C. TI is the temperature inflection point for a piecewise segment in °C. TC is the temperature coefficient or gain of NST235. VOF is the voltage offset of NST235. Therefore, in a certain output voltage range (VR), given the output voltage value, the corresponding TA can be calculated using Equation 3-2. For accuracy insensitive applications, the parameters in the first row of Table 3.1 can be used directly. TA = (VO − VOF ) + TI TC (3-2) Table 3.1 NST235 Piecewise Linear Function Summary TA (°C) VR (mV) TI (°C) TC (mV/°C) VOF (mV) –40 to 100 < 1500 0 10 500 100 to 125 1500 to 1752.5 100 10.1 1500 125 to 150 > 1752.5 125 10.6 1752.5 Table 3.2 NST235 Transfer Table TEMPERATURE (°C) VOUT (mV) IDEAL LINEAR VALUES VOUT (mV) PIECEWISE LINEAR VALUES –40 100 100 –35 150 150 –30 200 200 –25 250 250 –20 300 300 –15 350 350 –10 400 400 –5 450 450 0 500 500 5 550 550 10 600 600 15 650 650 20 700 700 Copyright © 2019, NOVOSENSE Page 6 NST235 Datasheet (EN) 1.2 Table 3.2 NST235 Transfer Table(Continued) TEMPERATURE (°C) VOUT (mV) IDEAL LINEAR VALUES VOUT (mV) PIECEWISE LINEAR VALUES 25 750 750 30 800 800 35 850 850 40 900 900 45 950 950 50 1000 1000 55 1050 1050 60 1100 1100 65 1150 1150 70 1200 1200 75 1250 1250 80 1300 1300 85 1350 1350 90 1400 1400 95 1450 1450 100 1500 1500 105 1550 1550.5 110 1600 1601 115 1650 1651.5 120 1700 1702 125 1750 1752.5 130 1800 1805.5 135 1850 1858.5 140 1900 1911.5 145 1950 1964.5 150 2000 2017.5 Copyright © 2019, NOVOSENSE Page 7 NST235 Datasheet (EN) 1.2 3.3.2 Application Curve 2500 Output Voltage(mV) 2000 1500 1000 500 0 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Temperature(℃) Figure 3.2 Output Voltage vs Temperature 4 Application Information 4.1 Capacitive Loads As shown in the structure diagram, the output stage of NST235 is an amplifier. Generally, the output of the amplifier directly connected to the capacitive load is unstable. However, NST235 uses a special design, which makes it have 1000pF capacitive load capacity as shown in the Figure 4.1. If a larger capacitor is connected to filter the noise, an isolation resistance should be added between the output of NST235 and the capacitor as shown in the Table 4.1. When the equipment is in an extremely noisy environment, it may be necessary to add an RC low-pass filter network to the output of NST235, such as a 1µF capacitor and a 800Ω series resistor. This low-pass filter will improve the thermal response time of NST235 and has the function of filtering high-frequency noise as shown in the Figure 4.2. VDD NST235 Vo C GND Figure 4.1 NST235 No Decoupling Required for Capacitive Loads Less Than 1000pF Copyright © 2019, NOVOSENSE Page 8 NST235 Datasheet (EN) 1.2 Table 4.1 Capacitive Loading Isolation C (μF) Minimum R(Ω) 1 800 0.1 to 0.999 1500 0.01 to 0.099 3000 VDD Vo NST235 R C GND Figure 4.2 NST235 with RC Filter 4.2 Typical Application As shown in Figure 4.3, the NST235 has an extremely low supply current and a wide supply range, therefore, it can be easily driven by a battery. In order to reduce the noise in the output voltage, it is recommended to add a 0.1µF capacitor between the power and the ground. V+(+2.3V to +5.5V) VDD VO NST235 GND NC Figure 4.3 Typical Connections of the NST235 4.3 System Examples 4.3.1 Conserving Power Dissipation with Shutdown Although NST235 has extremely low power consumption, for power-sensitive applications it can simply be shutdown by driving its supply pin with the output of a logic gate as shown in Figure 4.4. VDD Shutdown NST235 Vo Any logic device output GND Figure 4.4 Conserving Power Dissipation with Shutdown Copyright © 2019, NOVOSENSE Page 9 NST235 Datasheet (EN) 1.2 4.3.2 Analog-to-Digital Converter Input Stage The input structure of most CMOS ADCs is sample and hold structure. When ADC charges the sampling capacitor, it needs to draw instantaneous current from the signal source (such as NST235 temperature sensor and many operational amplifiers). By adding RC filter to the output stage of NST235, this requirement can be met. At this time, the instantaneous current is provided by the output capacitor. This ADC is shown as an example only, in Figure 4.5. VDD VDD R 0.1μF Bypass Optional Vin NST235 ADC C GND GND Figure 4.5 Suggested Connection to a Sampling Analog to Digital Converter Input Stage Copyright © 2019, NOVOSENSE Page 10 NST235 Datasheet (EN) 1.2 5 PACKAGE INFORMATION 5.1 SOT-23(3) Package Copyright © 2019, NOVOSENSE Page 11 NST235 Datasheet (EN) 1.2 The Small Circle Corresponds to Pin 1 of the Chip Tape and Reel Information of SOT-23(3) Copyright © 2019, NOVOSENSE Page 12 NST235 Datasheet (EN) 1.2 5.2 SC70(5) Package Copyright © 2019, NOVOSENSE Page 13 NST235 Datasheet (EN) 1.2 The Small Circle Corresponds to Pin 1 of the Chip Tape and Reel Information of SC70(5) Copyright © 2019, NOVOSENSE Page 14 NST235 Datasheet (EN) 1.2 6 Order Information NST235 Type -DSCR Unit MSL Marking Description NST235-DSTR 3000ea/Reel 1 235XXX SOT-23(3) package, Reel NST235-DSCR 3000ea/Reel 1 23XX SC70(5) package, Reel NOTE: All packages are RoHS-compliant with peak reflow temperatures of 260 °C according to the JEDEC industry standard classifications and peak solder temperatures (Reflow profile: J-STD-020E). Copyright © 2019, NOVOSENSE Page 15 NST235 Datasheet (EN) 1.2 7 Revision History Revision 1.0 1.1 1.2 Description Initial Version Revise information. Optimize text presentation Update Functional Description. Update Pin Configuration Diagram. Update Load Regulation of Electrical Characteristics.Revise Application Information. Optimize Text Presentation.Tape and reel show 1 pin. Copyright © 2019, NOVOSENSE Date 2020/11/28 2022/03/30 2022/08/04 Page 16 NST235 Datasheet (EN) 1.2 IMPORTANT NOTICE The information given in this document shall in no event be regarded as any warranty or authorization of, express or implied, including but not limited to accuracy, completeness, merchantability, fitness for a particular purpose or infringement of any third party’s intellectual property rights. You are solely responsible for your use of Novosense’ products and applications, and for the safety thereof. 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