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an amplifier used for driving a ultrasound transmiting transducer

ying liu
Prodigy 20 points
Other Parts Discussed in Thread: TAS5342LA, TAS5508C, PCM1808, TAS5611

Could anyone recommend me an amplifier used for a ultrasound transmitting transducer? The maximum input voltage is 40Vp-p,and the operating frequency is about 40kHz.

  • 0
    TI__Expert 7925 points

    Hello, Ying. The closest I can recommend is an open loop power stage amplifier, such as the TAS5342LA. The open loop response will offer a better gain at 40 kHz than our closed loop parts (which roll off quickly at 20 kHz), and you can design an output filter around 40 kHz signals. The TAS5342LA requires a modulator to produce the PWM inputs it needs, so it can be used with the TAS5508C or similar, which in turn takes in digital audio. Your input voltage range seems pretty large. If it's 40 Vp-p analog, I don't think we can handle that range.

    Please see this forum post for another discussion on the topic. http://e2e.ti.com/support/amplifiers/audio_amplifiers/f/6/t/206911.aspx

    Best Regards,
    Matt

  • 0 in reply to Matt Lauer
    Prodigy 20 points

    I want this amplifier to amplify a 40kHz sinusoidal signal. Is the input of TAS5342LA must a PWM signal?

  • 0 in reply to ying liu
    TI__Expert 7925 points

    Hi, Ying. Yes, the TAS5342LA requires a PWM input signal, because it acts only as a power stage in an amplifier system. Most TI power stages that are open loop accept only digital signals as their input. An ADC like the PCM1808 can take analog signals in and output to digital audio, needed for the TAS5508C.

    How much output power does your application require? Any of the TI parts in the following link offer analog input and open control loop. Please have a look. http://www.ti.com/paramsearch/docs/parametricsearch.tsp?sectionId=630&tabId=2701&family=analog&uiTemplateId=AUDIO_PRDSRCH_T&familyId=1976#p776=Analog&p2614=Open

    40 Vp-p analog input still seems fairly large. BUT a part like LM4780 can handle such a range with a large enough power supply. Have a look for yourself and see it it fits your needs.

    Regards,
    Matt

  • 0 in reply to Matt Lauer
    Prodigy 120 points

    Do you have any recommandation about the possibility of using your closed loop references for 20KHz to 30KHz range which is quite close of audio range?

    TAS5611/13 for example ?