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STMicroelectronics TSH512CFT
- Part No.:
- TSH512CFT
- Manufacturer:
- STMicroelectronics
- Category:
- RF Transmitters
- Package:
- 44-LQFP
- Datasheet:
-
TSH512CFT.pdf
- Description:
- RF TX IC FM 400KHZ-11MHZ 44LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,649
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Product details
Overview
TSH512CFT from STMicroelectronics is a dual FM infrared transmitter IC integrating two independent stereo audio transmission channels, each with low-noise LNA, ALC, pre-emphasis amplifier, voltage-controlled oscillator (0.4–11 MHz), and linear output buffer. It operates from 2.3–5.5 V, supports VOX activation and mono standby mode, and targets high-fidelity IR stereo headsets and sub-carrier generation for wireless video systems.
For engineers reviewing the TSH512CFT datasheet, TSH512CFT pinout, TSH512CFT application, or TSH512CFT equivalent, this device delivers verified FM modulation performance with sinusoidal carriers for spectral purity, micro/line-level input flexibility, and integrated power-saving VOX and SBY control-critical for battery-powered IR audio links and voice-activated camera transmitters.
Technical Context
The TSH512CFT implements two fully independent FM transmitter chains: each includes a differential LNA (30 kΩ input resistance, 7 MHz GBW), ALC with regulated 600–800 mVpp output, 9 MHz PEA stage, and VCO with 1.43–1.51 V bias output driving external LC tanks. Carrier frequency is set externally via pins VCO-A1/B1 and VCO-A2/B2.
Its VOX circuitry uses three dedicated pins (VOX-INTS, VOX-INTN, VOX-TIMER) to configure integrator time constants and sensitivity, while the SBY pin disables TX2 for mono operation-reducing total supply current from 16 mA to 10 mA (typ). All analog sections are optimized for low THD (0.01% LNA, 0.05% PEA) and high PSRR (50 dB MIC-BIAS).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 2.3–5.5 V - Enables direct use with single Li-ion or dual AA batteries without regulation. |
| Carrier Frequency Range | 0.4–11 MHz - Covers standard IR audio bands (2.3/2.8 MHz) and video sub-carriers (4.5/5.5 MHz). |
| LNA Input Resistance | 30 kΩ - Matches electret microphone impedance and minimizes loading on line-level sources. |
| ALC Regulated Output | 600–800 mVpp - Stabilizes modulation index across varying input levels to prevent over-deviation. |
| VCO Bias Voltage | 1.43–1.51 V - Provides precise DC bias for external LC tank, ensuring stable oscillation amplitude and frequency. |
| THD (LNA) | 0.01% (typ) at 1 kHz - Ensures high-fidelity audio amplification before FM modulation. |
| VOX Current Consumption | Reduces total ICC from 16 mA to ≤10 mA in mono standby - Extends battery life in headset applications. |
Pinout & Package
TSH512CFT is housed in a 44-pin TQFP44 package (10 × 10 mm, 0.8 mm pitch), thermally enhanced with exposed pad for junction-to-case Rthjc = 14 °C/W.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 12, 44 | LNA-INP1 / LNA-INP2 | Differential positive inputs for left/right channel microphones or line sources. |
| 13, 43 | LNA-INN1 / LNA-INN2 | Differential negative inputs - enables noise rejection in unbalanced or balanced configurations. |
| 5 | SBY | Active-high standby control: disables TX2 to reduce current by ~40% for mono operation. |
| 27 | VOX-MUTE | Open-drain output that asserts low during silence - directly gates LED driver or RF stage enable. |
| 18, 38 | VCO-BIAS1 / VCO-BIAS2 | Stable 1.43–1.51 V reference outputs - sets DC operating point for external LC tank components. |
| 20, 21, 35, 36 | VCO-A1/B1 / VCO-A2/B2 | External LC connection points - define carrier frequency and tuning range per channel. |
| 22, 34 | VCO-OUT1 / VCO-OUT2 | High-impedance sinusoidal outputs - feed directly into buffer input (BUF-IN1/2) for clean FM drive. |
| 24, 32 | BUF-IN1 / BUF-IN2 | High-Z (400 kΩ) inputs accepting VCO-OUT signals - minimize loading on oscillator core. |
| 25, 31 | BUF-OUT1 / BUF-OUT2 | 10 dB gain, 1.35–1.7 Vpp AC outputs - drive IR LEDs or external transistor buffers directly. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent FM transmitters | Enables true stereo IR transmission (e.g., 2.3 MHz left + 2.8 MHz right) without cross-talk or shared resources. |
| Sinusoidal carrier generation | Reduces harmonic content vs. square-wave carriers - simplifies bandpass filtering and improves EMI compliance. |
| Integrated VOX with configurable timing | Three external RC pins (VOX-INTS/INTN/TIMER) allow precise adjustment of activation delay, hold time, and sensitivity. |
| Microphone bias with 2.25 V ±100 mV accuracy | Stable 2.25 V @ 2.5 mA eliminates need for external bias circuitry in electret mic interfaces. |
| ALC with 20 dB gain and 600–800 mVpp regulated output | Maintains consistent FM deviation regardless of input level - prevents distortion and ensures SNR stability. |
Applications
| Infrared Stereo Headphones | Voice-Activated Wireless Webcam |
|---|---|
|
Use Scenario: Battery-powered stereo headphones receiving audio from PC or media player via IR link. IC Role / Device Role / Timing Role: Dual-channel FM transmitter generating synchronized 2.3 MHz (left) and 2.8 MHz (right) carriers with VOX-gated LED drive. Use Value: Delivers Hi-Fi audio with <0.05% THD and 20+ hour runtime using dual AA cells due to VOX and SBY power management. |
Use Scenario: USB webcam with IR audio sub-carrier for voice commentary overlay on video stream. IC Role / Device Role / Timing Role: Sub-carrier generator producing 4.5 MHz FM-modulated voice signal, triggered by VOX-MUTE to activate only during speech. Use Value: Eliminates continuous RF transmission - reduces EMI, extends battery life, and avoids interference with Wi-Fi/Bluetooth. |
| Stereo Audio Sub-Carrier Generator | FM IF Transmit System |
|
Use Scenario: Broadcast equipment embedding stereo audio into composite video using IR sub-carriers. IC Role / Device Role / Timing Role: Dual VCO-based generator providing two independent, spectrally pure carriers (e.g., 5.5 MHz + 6.0 MHz) for L/R channels. Use Value: Sinusoidal outputs enable sharp filtering; ALC ensures constant modulation depth across dynamic speech/music content. |
Use Scenario: Industrial telemetry system transmitting sensor audio over FM IF band (e.g., 10.7 MHz) with low-power remote nodes. IC Role / Device Role / Timing Role: High-stability FM modulator with 0.4–11 MHz carrier range - configured for 10.7 MHz IF using external LC network. Use Value: VCO-BIAS regulation and low phase noise (−80 dBc @ 1 kHz) preserve IF signal integrity in noisy factory environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual FM transmitter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX2112ETJ+ | Single-channel FM transmitter; requires external dual-LNA and ALC; no integrated VOX or SBY. | Lacks stereo integration and power-saving features - needs additional ICs for equivalent functionality. | Select when board space allows discrete implementation and VOX is handled externally. |
| Si2151-A10-GM | RF tuner IC with integrated IF demodulator; not a transmitter - lacks LNA, ALC, VCO, and buffer stages. | Designed for receiver-side IF processing, not FM signal generation - functionally incompatible. | Not suitable as functional replacement; only relevant for full transceiver system analysis. |
Compared with MAX2112ETJ+, TSH512CFT integrates both channels, VOX, and ALC in one die-reducing BOM count and layout complexity. Unlike Si2151-A10-GM, it is a purpose-built transmitter with verified IR-band FM performance and thermal specs for continuous operation.
Availability
TSH512CFT is available at Aetrix Electronics and suitable for infrared stereo headsets, voice-activated wireless webcams, and FM IF transmit systems requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.
Supply support for TSH512CFT 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 headquartered in Geneva, Switzerland, specializing in analog, power, and automotive ICs with strong IP in mixed-signal design and manufacturing.
The TSH512CFT belongs to ST's infrared audio transmission product line, engineered specifically for low-power, high-fidelity wireless audio links in consumer and professional AV equipment.
FAQ
What is the maximum recommended carrier frequency for reliable operation?
The TSH512CFT is characterized up to 11 MHz, with verified performance at 2.8 MHz (stereo headphones) and 4.5 MHz (video sub-carrier). At 11 MHz, VCO output drops to 569 mVpp (min), requiring careful LC tank Q-factor selection and reduced load impedance to maintain modulation fidelity.
Can the TSH512CFT drive IR LEDs directly without external transistors?
Yes - BUF-OUT1/2 deliver 1.35–1.7 Vpp into 2 kΩ loads, sufficient to drive low-threshold IR LEDs (e.g., HSDL-4230) at ~20 mA peak with series resistor. For higher current or longer range, external NPN/PNP buffers are recommended per Figure 22 in the datasheet.
How does the VOX circuit distinguish speech from background noise?
The VOX uses dual integrators: VOX-INTS sets audio signal detection threshold, VOX-INTN configures noise floor tracking, and VOX-TIMER defines mute hold time. This three-pole architecture rejects short bursts and maintains transmission during pauses in natural speech.
Is the TQFP44 package RoHS-compliant and lead-free?
Yes - the TSH512CFT (TQFP44) is manufactured per RoHS Directive 2011/65/EU and JEDEC J-STD-020, with lead-free terminations and halogen-free molding compound. The exposed thermal pad is solderable and must be connected to GND for optimal thermal performance.
TSH512CFT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 44-LQFP
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Frequency:
- 400kHz ~ 11MHz
- Applications:
- Infrared Headsets, Infrared Hi-Fi Stereo Transmitters
- Modulation or Protocol:
- FM
- Data Rate (Max):
- -
- Power - Output:
- -
- Current - Transmitting:
- 16mA
- Data Interface:
- PCB, Surface Mount
- Antenna Connector:
- PCB, Surface Mount
- Memory Size:
- -
- Features:
- -
- Voltage - Supply:
- 2.3V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 44-TQFP (10x10)
TSH512CFT FAQ
1.How can I place an order for TSH512CFT through Aetrix?
Please submit a Request for Quotation (RFQ) for TSH512CFT on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TSH512CFT reliable?
The price and inventory of TSH512CFT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TSH512CFT is usually 5 days.
3.What payment methods are accepted for TSH512CFT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TSH512CFT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TSH512CFT?
TSH512CFT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TSH512CFT order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TSH512CFT?
For technical support, including TSH512CFT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TSH512CFT requirements.
6.How does Aetrix verify that TSH512CFT is sourced from the original manufacturer or authorized distributors?
All TSH512CFT products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TSH512CFT meets industry standards.
7.What is the process for return or replacement of TSH512CFT?
All TSH512CFT units undergo pre-shipment inspection (PSI). If there is an issue with TSH512CFT, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TSH512CFT part is unused and in its original packaging.
Return procedure for TSH512CFT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TSH512CFT Tags
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