STHV800 Octal 90 V, 2 A, 3-level RTZ, high-speed ultrasound pulser Data brief Fully integrated real clamping-to-ground function 8 synchronous active clamp 2 A source and sink current Fully integrated TR switch 8 ON resistance Up to 300 MHz BW Current consumption down to 10 A in RX phase Receiver multiplexing function 1.8 V to 3.6 V CMOS logic interface Auxiliary integrated circuits Noise blocking diodes Anti-leakage on output node TFLGA-56LD(8x8x0.9 mm) Fully self-biasing architecture Thermal protection Latch-up free due to HV SOI technology Features Very few external passive components or supplies needed High-density ultrasound transmitter Two independent half-bridges per channel 0 to 90 V output voltage Applications Power-up free Medical ultrasound imaging Synchronization of the input signals Pulse waveform generator (selectable) by an external clock NDT ultrsound transmission Up to 20 MHz operating frequency Piezoelectric transducer drivers Low-power, high-voltage, high-speed drivers Point-of-care ultrasound imaging equipment 2 independently-supplied half bridges (shorted-option) for each channel, one dedicated to continuous wave (CW) mode Table 1: Device summary Main half bridge: 2 A source and sink current Order code Package Packing Down to 20 ps jitter STHV800L TFLGA-56LD Tape and reel Low 2nd harmonic distortion CW half bridge: 0.3 A source and sink current Down to 10 ps jitter Very low power consumption April 2014 DocID026018 Rev 2 1/5 www.st.com For further information contact your local STMicroelectronics sales office Description STHV800 1 Description The STHV800 is an octal, monolithic, high-voltage and high-speed pulse generator. It is designed for medical ultrasound applications, but can be used for other piezoelectric, capacitive or MEMS transducers. The device integrates a controller logic interface circuit (compatible with both 1.8 V and 3.3 V input signals), level translators, MOSFET gate drivers, noise blocking diodes, and high power P-channel and N-channel MOSFETs as the output stage for each channel. These MOSFETs are capable of providing more than 2 A of peak output current. Each channel has a dedicated bridge in order to reduce power dissipation and jitter during continuous wave mode (peak current is limited to 0.3 A). This CW bridge has dedicated power supplies (HV CW) which are fully independent on the main HV supplies. These HV CW supplies can be shorted to the HV supplies. The fundamental structure of each channel also consists of active clamping to ground circuitry, anti-leakage and anti- memory block, a thermal sensor to protect the device and an integrated TR-switch (just 8 as equivalent resistor ) to connect the HV output to its LV output, guaranteeing strong decoupling during the transmission phase. The eight independent T/R switches can be used in both a dedicated RX chain per channel or in a multiplexing configuration. The clamp circuit has a current capability up to 2 A and works directly on the output pin, carrying this node exactly to zero. This feature allows minimized injection change during the transition from clamp to RX state. In addition, the STHV800 includes self-biasing circuitry which allows very low power consumption during the RX phase (down to 200 W global power dissipation) and thermal shutdown block sensing by an external dedicated pin (THSD). One of the main benefits of this device is that it requires very few external components: only decoupling capacitors on the HV and LV supplies, and a resistor to pull up the THSD pin (moreover, this resistor can be shared by many devices). Each channel is driven independently by only 2 digital bits, which in CW mode become one bit. An external clock can be used with the STHV800 to synchronize all the input signals. This feature, however, is optional: if the CK pin is tied to ground the device works in asynchronous mode. 2/5 DocID026018 Rev 2