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Linear公司的LTC2997是高精度模擬輸出溫度傳感器,遙控溫度的精度為±1℃,內部溫度測量的精度為±1.5℃,內置了串聯(lián)電阻消除,工作電壓2.5V-5.5V,輸出增益4mV/°C,靜態(tài)電流170uA,1.8V基準電壓輸出,主要用在溫度測量,遙控溫度測量,環(huán)境監視,系統熱量控制,筆記本和臺式電腦以及網(wǎng)絡(luò )服務(wù)器.本文介紹了LTC2997主要特性, 方框圖,以及遙控和遙測多種應用電路. LTC2997 Features Description Remote/Internal Temperature Sensor The LTC2997 is a high-accuracy analog output temperature sensor. It converts the temperature of an external sensor or its own temperature to an analog voltage output. A built-in algorithm eliminates errors due to series resistance between the LTC2997 and the sensor diode. The LTC2997 gives accurate results with low-cost diodeconnected NPN or PNP transistors or with integrated temperature transistors on microprocessors or FPGAs.Tying pin D+ to VCC configures the LTC2997 as an internal temperature sensor.The LTC2997 provides an additional 1.8V reference voltage output which can be used as an ADC reference input or for generating temperature threshold voltages to compare against the VPTAT output. The LTC2997 provides a precise and versatile micropower solution for accurate temperature sensing. LTC2997主要特性: Converts Remote Sensor or Internal Diode Temperature to Analog Voltage ±1℃ Remote Temperature Accuracy ±1.5℃ Internal Temperature Accuracy Built-In Series Resistance Cancellation 2.5V to 5.5V Supply Voltage 1.8V Reference Voltage Output 3.5ms VPTAT Update Time 4mV/℃ Output Gain 170μA Quiescent Current Available in 6-Pin 2mm × 3mm DFN Package LTC2997應用: Temperature Measurement Remote Temperature Measurement Environmental Monitoring System Thermal Control Desktop and Notebook Computers Network Servers 
圖1. LTC2997方框圖
圖2. LTC2997單個(gè)遙控溫度傳感器應用框圖
圖3. LTC2997內部溫度傳感器應用框圖
圖4. LTC2997遙控CPU溫度傳感器應用框圖
圖5. LTC2997單線(xiàn)遙控溫度傳感器應用框圖
圖6. LTC2997輸出噪音濾波器電路圖
圖7. LTC2997長(cháng)距離遙控溫度傳感器應用框圖
圖8. LTC2997模擬PWM加熱器控制框圖
圖9. LTC2997 75°C模擬加熱器控制框圖
圖10. LTC2997溫度到位數的轉換圖
圖11. LTC2997正比溫度的PWM風(fēng)扇速度控制器 詳情請見(jiàn): http://cds.linear.com/docs/Datasheet/2997f.pdf |
