TSZ182 datasheet(30/39 Pages) STMICROELECTRONICS

Nome de Peças	TSZ182

Descrição Electrónicos	Very high accuracy (25 μV) high bandwidth (3 MHz) zero drift 5 V dual operational amplifiers

PDF	39 Pages

Scroll/Zoom	100%

Fabricante Electrônico	STMICROELECTRONICS [STMicroelectronics]

Página de início	http://www.st.com

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30 / 39 page

Application information

TSZ182

30/39

DocID029836 Rev 1

Moreover, the drift of Vio depending on temperature must be as low as possible not to

impact the measurement once the calibration has been made.

An NDIR sensor generally works at low frequency and the noise of the amplifiers must be

as low as possible (0.1-10 Hz en-pp = 0.4 µVpp).

Thanks to its chopper architecture, the TSZ182 combines all these specifications,

particularly in having a ΔVio/Δt of 0.1 µV/°C, no 1/f noise in low frequency, and a white

noise of 37 nV/√Hz.

Figure 62: "Principle schematic" shows an NDIR gas sensing schematic where the active

and reference channels are pre-amplified before treatment by an ADC thanks to the

TSZ182.

A Vref voltage (in hundreds of mV) can be used to ensure the amplifiers are not saturated

when the signal is close to the low rail. A gain of 1000 is used to allow amplification of the

signal coming from the NDIR sensor (3 mV).

Figure 62: Principle schematic

Ref.ch

Act. ch

Vref

10 Ω

10 nF

ADC2

ADC1

ADC3

10 Ω

100 nF

10 k

Ω

10 k

Ω

Vcc

T SZ 182_a

T SZ 182_b

TSZ182 Folha de dados(PDF) 30 Page - STMicroelectronics