Realizes high-sensitivity and high-precision sensing performance

Low-noise op-amp suitable for amplifying weak sensor outputs

The role of various sensors (motion detector, distance sensors, current sensors, etc.) built into home appliances, which are rapidly becoming smarter, are increasing. There are various types of sensor used in home appliances, but the detected signals output from the sensor are very weak, so in general, they are amplified by an op-amp. The op-amp used for amplification is required to have a low noise level so that its own noise does not mask the weak sensor output.
TC75S67TU is a low-noise op-amp that significantly improves equivalent input noise voltage (VNI) compared to existing products. In addition, since the input bias current is small, an offset adjusting resistor is not required.
By using TC75S67TU with high-performance sensor components, high-sensitivity and high-precision sensing performance can be realized.
This section introduces the noise characteristics of TC75S67TU and examples for sensing applications.

Product Features

Equivalent input noise voltage

The noise is two types, one is 1/f noise distributed in the low frequency range and another is white noise distributed in the wide range. Both noise level of TC75S67TU are greatly improved compared with existing products.
The low noise level of 6 nV/√Hz (typical, GV=40dB) at f=1 kHz, which is 82 %, and 16 nV/√Hz (typical, GV=40dB) at f=10 Hz, which is an 86 % better than our existing product. The noise characteristics below shows flat in wide frequency range compared with existing product.

Equivalent input noise voltage

Since the equivalent input noise voltage is defined as the input signal level which dividing the output noise of the op-amp by the gain. If this value is smaller, then the op-amp can handle weaker input signal. This means that the sensor element output can be handled at a lower level, thus sensing performance such as sensitivity and accuracy are improved.
Such noise characteristics of TC75S67TU improves the sensing performance of various sensors. It is particularly useful for improving the performance of pulse and motion detectors with lower signal frequencies.

Reference designs of various sensor applications

We post sensor application reference designs using TC75S67TU on website. Each of them is used for amplifying signals and filtering unwanted frequency components. Application circuits and board pattern diagrams are available on the web. Please use them from each link destination.

Pulse sensor

Light is irradiated on the blood flow and the reflected light is detected by the photo sensor. Reference design has two boards, one is sensor unit and the other is amplifier unit. 
To download the Pulse sensor reference design

Motion sensor

Pyroelectric infrared sensor element detects temperature changes using infrared rays generated by human movement.
To download the Motion sensor reference design

Current sensor

A 100 mΩ shunt resistor detects the current as a voltage. The current signal is very small so TC75S67TU amplifies it, output amplified signal to MCU, then MCU reads the voltage and converts as current to show.
To download the Current sensor reference design

Distance sensor

The distance is calculated by measuring the time between transmitting ultrasonic wave and receiving the wave reflected by an object by ultrasonic sensor.
To download the Distance sensor reference design

A wide range of products is available, including low noise type, low current consumption type, and input/output full range type (input/output Rail to Rail).

Part Number

Stock Checking



(Width×Length×Height mm)

SOT-353F (UFV)

SOT-353F (UFV)

Operating Ratings

Supply voltage VDD-VSS (V)

2.2 to 5.5

Electrical Characteristics

Supply current IDD (μA)

typ. @VDD=2.5V


max @VDD=2.5V 700

Input offset voltage VIO (mV)

max @VDD=2.5V


Source current Isource (mA) typ. @VDD=2.5V 2.5

Sink current Isink (mA)

typ. @VDD=2.5V


typ. @VDD=2.5V, f=10Hz 16
Equivalent input Noise Voltage VNI (nV/√Hz) typ. @VDD=2.5V, f=1kHz 6
Unity Gain Cross Frequency fT (MHz) typ. @VDD=2.5V


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