LM1812 Datasheet | National Semiconductor

Description The LM1812 is a general purpose ultrasonic transceiver designed for use in a variety of ranging sensing and munications applications The chip contains a pulse-modulated class C transmitter a high gain receiver a pulse modulation detector and noise rejection circuitry A single LC network defines the operating frequency for both the transmitter and receiver The class C transmitter output drives up to 1A (12W) peak at frequencies up to 325 k Hz The externally programmed receiver gain provides a detection sensitivity of 200 m Vp-p Detection circuitry included on-chip is capable of rejecting impulse noise with external programming The detector output sinks up to 1A Applications include sonar systems non-contact ranging and acoustical data links in both liquid and gas ambients Features Y One or two-transducer operation Y Transducers interchangeable without realignment Y No external transistors Y Impulse noise rejection Y No heat sinking Y Protection circuitry included Y Detector output drives 1A peak load Y Ranges in excess of 100 feet in water 20 feet in air Y 12W peak transmit power Applications Y Liquid level measurement Y Sonar Y Surface profiling Y Data links Y Hydroacoustic munications Y Non-contact sensing Y Industrial process control Typical Application Order Number LM1812N See NS Package Number N18A TL H 7892 - 1 Note Echo returns are displayed by a neon lamp on a motor driven disc Connections to the neon are made through brushes and slip rings Rotating with and counterbalancing the neon lamp is a permanent magnet whose field induces a pulse in a stationary coil (L8) as it passes by This pulse keys the LM1812’s transmitter Available from Toko America 1250 Feehanville Drive Mount Prospect Illinois 60056 Tel (312) 297-0070 Available from Massa Products Corporation 280 Lincoln Street Hingham Massachusetts 02043 Tel (617) 749-4800 FIGURE 1 200 k Hz Depth Sounder 5 Feet to 100 Feet C1995 National Semiconductor Corporation TL H 7892 RRD-B30M115...