2019-11-10 21:23:00 来源: 永州信息港
TI LMP91000低功耗化学传感器模拟前端解决方案 - 模拟电子技术 - 电子工程
TI公司的LMP91000是可编程低功耗化学传感器模拟前端(AFE),提供传感器和MCU间完整的信号通路解决方案.气体灵敏度从0.5 nA/ppm到9500 nA/ppm,很容易转换成电流从5μA 到750μA.工作电压2.7V-5.25V工作电流小于10 μA,电池调理电流高达10mA,可编程电池偏压电压, 偏压电压漂移低.主要用在化学样品识别,电流计和电化学血糖仪.本文介绍了LMP91000主要特性,方框图,多种应用框图以及化学和气体传感器解决方案框图和蔼主要特性.
LMP91000 Sensor AFE System: Configurable AFE Potentiostat for Low-Power Chemical Sensing Applications
The LMP91000 is a programmable Analog Front End (AFE) for use in micro-power electrochemical sensing applications.
It provides a complete signal path solution between a sensor and a microcontroller that generates an output voltage proportional to the cell current. The LMP91000’s programmability enables it to support multiple electrochemical sensors such as 3-lead toxic gas sensors and 2-lead galvanic cell sensors with a single design as opposed to the multiple discrete solutions.
The LMP91000 supports gas sensitivities over a range of 0.5 nA/ppm to 9500 nA/ppm. It also allows for an easy conversion of current ranges from 5μA to 750μA full scale.
The LMP91000’s adjustable cell bias and transimpedance amplifier (TIA) gain are programmable through the the I2C interface.
The I2C interface can also be used for sensor diagnostics.
An integrated temperature sensor can be read by the user through the VOUT pin and used to provide additional signal correction in the μC or monitored to verify temperature conditions at the sensor.
The LMP91000 is optimized for micro-power applications and operates over a voltage range of 2.7V to 5.25V. The total current consumption can be less than 10μA. Further power savings are possible by switching off the TIA amplifier and shorting the reference electrode to the working electrode with an internal switch.
Typical Values, TA = 25℃
■ Supply voltage 2.7 V to 5.25 V
■ Supply current (average over time) 10 μA
■ Cell conditioning current up to 10 mA
■ Reference electrode bias current (85℃) 900pA (max)
■ Output drive current 750μA
■ Complete potentiostat circuit to interface to most chemical cells
■ Programmable cell bias voltage
■ Low bias voltage drift
■ Programmable TIA gain 2.75kΩ to 350kΩ
■ Sink and source capability
■ I2C compatible digital interface
■ Ambient operating temperature -40℃ to 85℃
■ Package 14 pin LLP
■ Supported by Webench Sensor AFE Designer
■ Chemical species identification
■ Amperometric application
■ Electrochemical blood glucose meter民生评论