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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(nèi)部溫度測(cè)量的精度為±1.5℃,內(nèi)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(zhǔn)電壓輸出,主要用在溫度測(cè)量,遙控溫度測(cè)量,環(huán)境監(jiān)視,系統(tǒng)熱量控制,筆記本和臺(tái)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(cè)多種應(yīng)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(yīng)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(yīng)用框圖
圖3. LTC2997內(nèi)部溫度傳感器應(yīng)用框圖
圖4. LTC2997遙控CPU溫度傳感器應(yīng)用框圖
圖5. LTC2997單線遙控溫度傳感器應(yīng)用框圖
圖6. LTC2997輸出噪音濾波器電路圖
圖7. LTC2997長(zhǎng)距離遙控溫度傳感器應(yīng)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(shù)的轉(zhuǎn)換圖
圖11. LTC2997正比溫度的PWM風(fēng)扇速度控制器 詳情請(qǐng)見(jiàn): http://cds.linear.com/docs/Datasheet/2997f.pdf |
