ZHCSCH2E January 2014 – October 2017 LMT87
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 5 Device Comparison Tables
- 6 Pin Configuration and Functions
- 7 Specifications
- 8 Detailed Description
- 9 Application and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12器件和文檔支持
- 13機械、封裝和可訂購信息
封裝選項
機械數據 (封裝 | 引腳)
散熱焊盤機械數據 (封裝 | 引腳)
訂購信息
9 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
9.1 Application Information
The LMT87 features make it suitable for many general temperature-sensing applications. It can operate down to 2.7-V supply with 5.4-µA power consumption. Package options like the through-hole TO-92 package also allow the LMT87 to be mounted onboard, off-board, to a heat sink, or on multiple unique locations in the same application.
9.2 Typical Applications
9.2.1 Connection to ADC
Figure 13. Suggested Connection to a Sampling Analog-to-Digital Converter Input Stage
9.2.1.1 Design Requirements
Most CMOS ADCs found in microcontrollers and ASICs have a sampled data comparator input structure. When the ADC charges the sampling cap, it requires instantaneous charge from the output of the analog source such as the LMT87 temperature sensor and many op amps. This requirement is easily accommodated by the addition of a capacitor (CFILTER).
9.2.1.2 Detailed Design Procedure
The size of CFILTER depends on the size of the sampling capacitor and the sampling frequency. Because not all ADCs have identical input stages, the charge requirements will vary. This general ADC application is shown as an example only.
9.2.1.3 Application Curve
Figure 14. Analog Output Transfer Function
9.2.2 Conserving Power Dissipation With Shutdown
Figure 15. Simple Shutdown Connection of the LMT87
9.2.2.1 Design Requirements
Because the power consumption of the LMT87 is less than 9 µA, it can simply be powered directly from any logic gate output and therefore not require a specific shutdown pin. The device can even be powered directly from a microcontroller GPIO. In this way, it can easily be turned off for cases such as battery-powered systems where power savings are critical.
9.2.2.2 Detailed Design Procedure
Simply connect the VDD pin of the LMT87 directly to the logic shutdown signal from a microcontroller.
9.2.2.3 Application Curves
INDENT:
Time: 500 μs/div; Top trace: VDD 1 V/div;Bottom trace: OUT 1 V/div
INDENT:
Time: 500 μs/div; Top trace: VDD 2 V/div;Bottom trace: OUT 1 V/div
INDENT:
Time: 500 μs/div; Top trace: VDD 1 V/div;Bottom trace: OUT 1 V/div
INDENT:
Time: 500 μs/div; Top trace: VDD 2 V/div;Bottom trace: OUT 1 V/div