TSH512 datasheet(19/31 Pages) STMICROELECTRONICS

Part #	TSH512

Description	Hi-fi stereo/mono infrared transmitter and stereo sub-carrier generator

PDF	31 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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TSH512

General description

Doc ID 8120 Rev 7

19/31

Figure 26.

LNA schematics

The LNA gain is given by:

GLNA (dB) = 20.Log(1+RLNA2/RLNA1)

The high-pass cut-off frequency is:

fHPF = 1/(2.π.RLNA1.CLNA1)

The lowpass filter cut-off frequency is:

fLPF = 1/(2.π.RLNA2.CLNA2)

If you connect an external circuit to the LNA output, the impedance of this external circuit

should be higher than 10 m

Ωand the capacitance lower than 50 pF in order to keep a good

stability.

Note:

The capacitor C must be connected directly to input pin 12.

5.2

Electret condenser microphone source

When an electret condenser microphone (ECM) is used, a high gain LNA is recommended,

but low frequencies have to be attenuated. The ECM must be biased with a stable and clean

reference voltage. The TSH512 provides the LNA and the MIC-BIAS sections to perform this

function (see Section 5.3. MIC-BIAS section: microphone bias voltage).

TSH512 Datasheet(PDF) 19 Page - STMicroelectronics