TSH511

General description

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General description

The TSH511 is a 0.4MHz to 11MHz dual FM analog receiver. The incoming signal is

amplified with a 22dB low noise amplifier (LNA) section. The good noise performance of the

LNA allows the photo diode for infrared applications to be connected directly to the TSH511

without any external preamplifier. The access pins for each section and the two standby

configurations offer high versatility for many applications: hi-fi stereo infrared receiver,

mono/stereo subcarrier receiver, power line carrier audio.

Figure 25.

TSH511 block diagram

The LNA is common to both receivers but the output is split in two: one for each receiver.

Each LNA output can be connected to a first optional filter for bandpass or reject filtering.

The filtered signal is amplified with an intermediate amplifier (AMP) section followed by a

second filter. The AMP sections have 20dB typical gain.

Finally, the signal is amplified and limited in the limiter (LIM) section. The 60dB amplifier-

limiter LIM provides a constant amplitude signal to the demodulator. It reduces AM parasitic

demodulation in the FM demodulator.

The FM demodulator is a classic quadrature detector that uses an external tank.

BUF-OUT2

BUF-OUT1

MUTE-OUT

MUTE-INT

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TSH511

Audio

buffers

Standby

RX1

RX2

SQUELCH

GND

SBY1

SBY2

VCC

DEC-OUT

GND

MUTE-IN

GND

AMP-IN2

VCC

LNA-OUT2

VCC

LNA-IN

GND

LNA-OUT1

VCC

AMP-IN1

DEC-LNA

Vref

LNA

amp.

limiter

FM demodulator

limiter

amp.

FM demodulator

BUF-OUT2

BUF-OUT1

MUTE-OUT

MUTE-INT

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1

TSH511

Audio

buffers

Standby

RX1

RX2

SQUELCH

GND

SBY1

SBY2

VCC

DEC-OUT

GND

MUTE-IN

GND

AMP-IN2

VCC

LNA-OUT2

VCC

LNA-IN

GND

LNA-OUT1

VCC

AMP-IN1

DEC-LNA

Vref

LNA

amp.

limiter

FM demodulator

limiter

amp.

FM demodulator