Practical application examples

TSA1203

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Practical application examples

9.1

Digital interface applications

The wide external buffer power supply range of the TSA1203 makes it a perfect choice for

plugging into 2.5 V or 3.3 V low voltage DSPs or digital interfaces.

9.2

Medical imaging applications

Driven by the increasing demand for applications requiring either portability or a high degree

of parallelism (or both), this product satisfies the requirements of medical imaging and

telecom infrastructures.

The typical system diagram in Figure 32, shows how a narrow input beam of acoustic

energy is sent into a living body via the transducer, and how the energy reflected back is

analyzed.

Figure 32. Medical imaging application

The transducer is a piezoelectric ceramic such as zirconium titanate. The whole array can

reach up to 512 channels. The TX beam former, amplified by the HV TX amps, delivers up to

100 V amplitude excitation pulses with phase and amplitude shifts. The mux and T/R switch

is a two way input signal transmitter/ output receiver.

To compensate for skin and tissues attenuation effects, the time gain compensation (TGC)

amplifier is an exponential amplifier that amplifies low voltage signals to the ADC input

range. A differential output structure with low noise and very high linearity are essential

factors.

These applications need high speed, low power and high performance ADCs. 10-12 bit

resolution is necessary to lower the quantification noise. As multiple channels are used, a

dual converter is a must for room saving issues.

The input signal is in the range of 2 to 20 MHz (mainly 2 to 7 MHz) and the application uses

mostly a 4 over-sampling ratio for spurious free dynamic range (SFDR) optimization.

The next RX beam former and processing blocks enable the analysis of the output channels

versus the input beam.

Mux and

T/R

switches

TX beam

former

Processing

and display

RX beam

former

ADC

TGC amplifier

HV TX amps