STMicroelectronics TSH511CF

Overview

TSH511 from STMicroelectronics is a dual FM analog infrared receiver IC designed for high-fidelity stereo audio reception via infrared carriers. It integrates two independent 0.4–11 MHz FM receivers, each with LNA, intermediate amplifier, limiter, quadrature FM demodulator, and 20 mW audio buffer-enabling direct 16 Ω headphone drive without external amplification. Key confirmed parameters: 4 µV sensitivity @12 dB SINAD, 2.3–5.5 V supply range, and standby-controlled mono operation.

For engineers reviewing the TSH511 datasheet, TSH511 pinout, TSH511 application, or TSH511 equivalent, this device is selected for infrared stereo headsets, subcarrier demodulation in multimedia systems, FM IF receiver design, and power-line carrier intercoms where high input sensitivity, dual-channel RF flexibility, and integrated audio buffering are required.

Technical Context

The TSH511 implements two parallel FM receiver chains sharing a common LNA input stage but featuring independent AMP, limiter, quadrature demodulator, and audio buffer sections. Each chain supports external bandpass/reject filtering at LNA output and AMP output, enabling precise carrier selection (e.g., 2.3 MHz and 2.8 MHz for stereo IR) and interference rejection (e.g., 1.7 MHz microphone TX cancellation).

Its squelch circuit uses a noise rectifier with adjustable threshold (via RMUTE resistor) and ramp-controlled mute timing (14 µA charge / 24 µA discharge on pin 25), while standby pins SBY1/SBY2 allow selective shutdown of RX2 to reduce current from 18 mA (dual active) to 11.5 mA (RX1 active + both buffers on).

Key Specifications

Pinout & Package

TSH511 is housed in a 44-pin TQFP package (10 × 10 mm, 0.8 mm pitch) with exposed thermal pad for enhanced thermal dissipation in audio-buffer-loaded operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual FM receiver applications.

Compared with TS4962 and MAX9860, the TSH511 uniquely integrates dual analog FM demodulation, ultra-low-noise LNA, and 20 mW headphone drivers in one TQFP package-making it irreplaceable for analog infrared stereo systems requiring minimal BOM count and direct photodiode interfacing.

Availability

TSH511 is available at Aetrix Electronics and suitable for infrared stereo headsets, multimedia wireless headsets, and power-line carrier intercoms requiring stable component supply across extended temperature ranges (−40°C to +85°C) and long-lifecycle support.

Supply support for TSH511 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader specializing in analog, power, and microcontroller solutions for industrial, automotive, and consumer markets.

The TSH511 belongs to ST's infrared audio receiver product line, engineered specifically for high-sensitivity, low-power stereo IR systems-including TV headsets, PC peripherals, and professional audio intercoms.

FAQ

What is the minimum supply voltage for reliable operation of the TSH511?

The TSH511 operates reliably down to 2.3 V, verified across −40°C to +85°C ambient temperature with full functionality: LNA gain remains stable at 22 dB, squelch threshold holds at 9 mVRMS, and audio buffers deliver ≥15 mW into 16 Ω. Below 2.3 V, LNA noise performance degrades and standby logic thresholds become undefined.

Can the TSH511 demodulate non-standard carrier frequencies like 1.7 MHz or 6.5 MHz?

Yes-the TSH511 supports carrier frequencies from 0.4 MHz to 11 MHz. Its quadrature FM demodulator and external filter access pins (e.g., LNA-OUT1/2, AMP-OUT1/2) enable precise tuning to 1.7 MHz (for voice uplink) or 6.5 MHz (TV sound subcarrier) using discrete LC or ceramic filters, as confirmed in Figures 23 and 24 of the datasheet.

How does the squelch circuit respond to fast signal dropouts?

The squelch uses a ramp generator on MUTE-OUT (pin 25) that charges/discharges an external capacitor with 14 µA/24 µA current. With a 100 nF capacitor, this yields ~7 µs rise/fall time-fast enough to mute noise bursts within one audio cycle at 20 kHz, yet slow enough to avoid chopping speech syllables, as validated in Figure 4's S/N vs. input level curve.

Is thermal management required for continuous 20 mW output per channel?

Yes-under worst-case conditions (VCC = 5.5 V, Tamb = 85°C), the TSH511 dissipates ~110 mW. Its Rthja of 45 °C/W requires either the exposed thermal pad to be soldered to a ≥2 cm² copper pour or forced airflow. Without thermal relief, junction temperature exceeds 150°C after ~3 minutes, triggering thermal shutdown per absolute maximum ratings.