TSH512CFT STMicroelectronics

TSH512 Hi-fi stereo/mono infrared transmitter and stereo sub-carrier generator Features Supply voltage: 2.3 to 5.5 V Carrier frequency range: 0.4 to 11 MHz F High versatility: I/O pins for each section TQFP44 Two FM transmitters for stereo 10 x 10 mm Sinusoidal carriers for high spectral purity Micro- or line-level preamplifiers with ALC Pin connections (top view) VOX function to save on battery power 3636 4444 4343 4242 4141 4040 3939 3838 3737 3535 3434 Transmitter TX2 standby for mono operation VCVCOO 11 3333 PEAPEA Applications 22 3232 ALALCC 33 OutOutpputut 3131 TX2TX2 Infrared hi-fi stereo transmitters bufbufffeerr LNLNAA 44 3030 TTSSHH512512 Infrared headsets 55 2929 Stereo sub-carriers for video transmitters 66 2828 VOVOXX Voice-operated wireless webcams 77 -- MMonoonosstatabbllee 2727 ++ 88 2626 FM IF transmit systems LNLNAA OutOutpputut 99 2525 + TX1TX1 bufbufffeerr ALALCC -+--++ --- 1010 2424 Description PEAPEA 1111 2323 VCVCOO The TSH512 is a 0.4- to 11-MHz dual FM 1212 1313 1414 1515 1616 1717 1818 1919 2020 2121 2222 transmitter. Access pins to each section give high versatility and allow for several different applications: stereo headphone, multimedia headset, audio sub-carrier generator. The TSH512 forms a chipset with the dual receiver TSH511. The TSH512 integrates in a single chip low-noise audio preamplifiers with ALC (automatic level control), frequency-modulated oscillators, and linear output buffers to drive the external transistors. The sinusoidal carriers facilitate the filtering and allow high performance audio transmission. The VOX (voice operated transmit) circuitry disables the output buffer when there is no audio signal to save battery power. For MONO applications, the STANDBY pin enables one transmitter only, reducing the supply current. May 2009 Doc ID 8120 Rev 7 1/31 www.st.com 31 + ++ - -Contents TSH512 Contents 1 Absolute maximum ratings and operating conditions . 3 2 Device diagrams and schematics 4 3 Electrical characteristics . 7 3.1 Supply section . 10 3.2 Audio section 10 3.3 RF section 13 4 Application information . 14 4.1 Infrared stereo transmitter application (stereo headphones) 14 4.2 Sub-carrier generator application: voice-operated wireless camera 16 4.3 Multimedia application . 16 4.3.1 Headset side . 16 4.3.2 Computer side 17 5 General description . 18 5.1 LNA section: low noise amplifier . 18 5.2 Electret condenser microphone source 19 5.3 MIC-BIAS section: microphone bias voltage 20 5.4 ALC section: automatic level control 21 5.5 VOX description: voice operated transmit 21 5.6 PEA section: pre-emphasis . 24 5.7 VCO section: voltage-controlled oscillator 25 5.8 Output buffer section 26 5.9 SBY pin: standby for mono operation 26 6 Package information 27 6.1 TQFP44 package information . 28 7 Ordering information . 29 8 Revision history . 30 2/31 Doc ID 8120 Rev 7