TI Sensing Solution Theory and
Key Applications
Kevin Zhang
2014-6-19
1
议程
• LDC1000电感到数字传感器
– 简介
– 原理分析
– 典型应用
– 设计指导
• HDC1000/1050温湿度传感器
• TDC1000超声模拟前端
• LMP93601热电堆传感器模拟前端
2
LDC1000简介
3
LDC Enables Inductive Sensing
LDC测量金属目标距离
LDC测量弹簧压缩
电感传感的优势:
不需要磁性器件
非接触式感应,可靠性高
抗环境干扰性能高
微米级精度
合理设计的线圈可使系统性能不会受温度变化影响
传感器成本低
电子器件可远离传感器
LDC1000
5.0V LDC, High-Res, 1-Channel
Features
Benefits
• Magnet-free operation
• Lower system costs
• Remote sensor location
• Higher reliability
• Greater system design flexibility
• Sub-micron resolution
• Contactless sensing
•
• Limitless design possibilities
Immunity to non-conductive interferences
• Supply Voltage (Analog) = 4.75-5.25V
• Supply Voltage (IO) = 1.8-5.25V
• Supply Current (Active) = 1.7mA
• Supply Current (Low-Power) = 250uA
• Channels = 1
• Oscillation Frequency = 5kHz-5MHz
• Oscillation Amplitude = 1 ~ 4 Vpp
• Rp Range = 1.25kΩ ~ 5MΩ
• Resolution = 16-bit (Rp) / 24-bit (L)
• Output = 4-Wire SPI, 4MHz Speed
• Temperature Range = -40C/+125C
• Package = SON16
Applications
• Position Sensing
• Angle/Rotation Sensing
• Gear/Event Counting & Motor Control
• Spring Compression/Twist Sensing
• Presence Detection
• Buttons & Switches
• Knobs & Slides
• Metal Composition Detection
4-WireSerialInterfaceINAINBSCLKSDISDOCSINTBVDDCFACFBPowerGNDVIODGNDCLDORsLCFrequency CounterTBCLK/XINXOUTThresholdDetectorTB RegisterRp RegisterLDCLDC1000SENSOR
基本应用
导体
线圈
距离测量
距离
导体
线圈
位移
导体
线圈
位移测量
角度测量
旋转角度
6
LDC1000原理分析
7
LDC1000工作原理
• 利用并联谐振原理
• 图中L为线圈,R为线圈的等效电阻,C为与线圈并联的电容
• LDC1000本质是电感和阻抗转换器
– 测量LC谐振腔的电感值
– 测量LC谐振腔的阻抗值
理想
情况
L
C
非理想
情况
R
L
C
8
IULICILCf210CRLIII.....IUZUIRLICILCRLCf20121RCLZ0...cLIII