Sensor Input

Example of gas detection circuit for measuring degree of air pollution

Circuit Description

空気汚染度測定用のガス検知回路例

For IoT sensor devices, the sensed data must be sent to the cloud with digital data of the sensing signal whether wired or wireless. Analog Digital Converter (ADC) is generally used to digital data conversion from the analog signal of the sensor output. One of the important indicators of ADC applications for accurate digital conversion is the input of an appropriate level of analog signal. Generally speaking, high-precision sensors often use delicate sensing elements and the output signal is often a minute analog signal. Therefore, in some cases, accurate digital conversion cannot be achieved even if the sensor output is directly input to the ADC. An operational amplifier is used in such cases.

An op-amp for amplifying analog signals from small level of signal sensor outputs to appropriate signal levels on the ACD inputs is required to make the noise performance of the op-amp itself extremely small in order to achieve high-precision amplification. It is also important to reduce the power consumption as much as possible in the application to IoT sensor devices. Toshiba offers a lineup of TC75S67TU, which is an optimum CMOS op amp for amplifying sensor signals in such IoT sensor devices. 

Stable power supplies are also critical to the low-noise performance of TC75S67TU. In order to make the power supply more stable, it is also recommended that the power supply for the op-amp be isolated from the power supply for other electronic circuits. The LDO-regulator's TCR3UG Series enables high-precision power supplies with low current draw. 

TC75S67TU achieves a low noise level of 6 nV/√Hz (f=1 kHz, GV=40 dB, typical) input-converted noise voltage. In addition, by adopting CMOS processing, low power dissipation is also realized at the same time.

Product name

Package
(Width×Length×Height mm)

Product Overview

Checking On-line distributor inventory

TC75S67TU

UFV
(2.0×2.1×0.7)

Ultra Low Noise Operational Amplifier,  VNI=6nV/√Hz (Typ.) (VDD=2.5V, f=1kHz)

TCR3UG series can contribute to low power consumption of the set due to its low current consumption characteristics, and has a lineup of 0.1V steps of output voltage as standard.

Product Number

Package
(Width×Length×Height mm)

Product Overview

Checking On-line distributor inventory

TCR3UG25A

WCSP4F
(0.645×0.645×0.33)

Low quiescent current 0.34μA (Typ.) (@IOUT=0mA), VOUT=2.5V (Typ.), IOUT=300mA (Max)

TCR3UG30A

WCSP4F
(0.645×0.645×0.33)

Low quiescent current 0.34μA (Typ.) (@IOUT=0mA), VOUT=3.0V (Typ.), IOUT=300mA (Max)

TCR3UG33A

WCSP4F
(0.645×0.645×0.33)

Low quiescent current 0.34μA (Typ.) (@IOUT=0mA), VOUT=3.3V (Typ.), IOUT=300mA (Max)
TCR3UG50A

WCSP4F
(0.645×0.645×0.33)

Low quiescent current 0.34μA (Typ.) (@IOUT=0mA), VOUT=5.0V (Typ.), IOUT=300mA (Max)

Other Circuit Description

AC-DC Power Supply

Other block diagrams

AC-DC forward power supply
Example of forward type AC-DC converter circuit
Application / IoT Sensor
Microphone amplifier circuit
Example of microphone circuit for voice recognition
Application / IoT Sensor
Temperature detection circuit
Example of temperature detection circuit using an NTC thermistor
Application / IoT Sensor
Humidity detection circuit
Example of humidity detection circuit using a resistive humidity sensor
Application / IoT Sensor
Ambient light detection circuit
Example of the ambient light detection circuit using a photodiode
Application / IoT Sensor
LED drive circuit
Example of LED drive circuit for operation status display
Application / IoT Sensor
Main control section
Example of main control section
Application / IoT Sensor

Other Technical Content

Uninterruptible Power Supply (UPS) Solution
Improving power supply performance and protection function contributes to energy saving and stable operation
Blood glucose meter solution
Realize high precision measurement and low power consumption in a small size
Surveillance Camera Solutions
Increasing demand of Functions and High resolution video
Programmable Logic Controller (PLC) Solution
Contributes to energy saving and stable operation by improving power supply performance and protective functions
Thermostat Solutions
Contributes to Product miniaturization, Long-life operation and Improvement of Quality and Reliability
Air Cleaner Solutions
Cleans Dirty Air by Linking "Filtration" with High-performance Filters and IoT
IoT sensor solutions
Ultra-low power consumption with high precision sensing in small size
Electric Toothbrush Solution
How to Obtain Oral Care that cannot be achieved by Human Hands?
Wireless Earphone Solution
For Long Time Operation with a Small Battery on a Wireless Earphone
Semiconductor Solutions for Air Conditioners
How to Increase Air Conditioning Performance without Increasing Power Consumption?
Smart Speaker Solution
Towards home network hub adding displays and cameras
Semiconductor Solutions for Servers
Contribute to Energy Saving and Stable Operation by Improving Power Supply Performance and Protective Functions
SSD Solution
Towards achievement compact size, high reliability and long life
Smartwatch Solution
To Realize More Features, Longer Operating Time and Smaller Size
Cordless Power Tool Solution
To Realize Compact, Light, Easy-to-Carry and Easy-to-Work with Long Time Operation