AN4472 datasheet(25/44 Pages) STMICROELECTRONICS

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AN4472

Hardware layout and configuration

Figure 17. Acquisition by Program 6, where C1, C2, C3 and C4 are XDCR_1, XDCR_2,

XDCR_3 and XDCR_4 respectively

Further customized pattern can be uploaded by user into remaining memory slots (thru .dfu

file - see UM1083.pdf), where it's tailored in base of the test necessities from final

application.

3.5

STHV749 stage

The STHV749 high-voltage, high-speed pulser generator features four independent

channels. It is designed for medical ultrasound applications, but can also be used for other

piezoelectric, capacitive, or MEMS transducers.

The device contains a controller logic interface circuit, level translators, MOSFET gate

drivers, noise blocking diodes, and high-power P-channel and N-channel MOSFETs as

output stages for each channel. There is also clamping-to-ground circuitry, anti-leakage, an

anti-memory effect block, a thermal sensor, and a HV receiver switch (HVR_SW) to ensure

strong decoupling during the transmission phase.

The STHV749 also includes self-biasing and thermal shutdown blocks (see block diagram in

Figure 18). Each channel can support up to five active output levels with two main half

bridges. It consists of three independently supplied output stages: two (TX0 and TX1) used

for pulsed wave (PW) and one for continuous wave (CW) operations. TX0 and TX1 are able

to provide up to ± 2 A peak output current each while, to reduce power dissipation and jitter

in continuous wave mode, the fully optimized CW output stage delivers up to ± 0.3 A. The

current capability for CW mode can also be set to 0.6 A.

The device can also be configured to operate as a 3-output-level, ± 4 A, 40 MHz pulser: this

mode can be selected via a dedicated input pin (SEL). In this configuration, the TX0 and

TX1 half bridges are paralleled in order to provide higher peak current and shorter pulse

waveforms, thus providing a higher output frequency.

AN4472 Datasheet(PDF) 25 Page - STMicroelectronics