1

HV732DB1

TheHV732isacomplete,high-speed,highvoltage,ultrasound

transmitter pulser. This integrated high performance circuit is

in a single 7x7x0.9mm 44-lead, multi-die, QFN package.

The HV732 can deliver up to ±2A source and sink current to

a capacitive transducer. It is designed to be used as a high

voltage pulser or transmitter in medical ultrasound imaging

and ultrasound material NDT applications. It can also be

used for other piezoelectric or capacitive MEMS transducers

as a high voltage driver, or for ATE systems and pulse signal

generators as a signal source.

The HV732 has built-in damping circuits to generate fast

return-to-zero waveforms. It also has built-in, high voltage

MOSFET gate-clamping functions to quickly change the

output waveform amplitude.

HV732 circuitry consists of controller logic circuits, level

translators, a MOSFET driving buffer, gate-clamp circuits

and MOSFET transistors as the high current and high

voltage output stage. There are two pairs of MOSFETs in

the output stage. Each pair is consists of a P-channel and an

N-channel MOSFET. In each pair of MOSFETs, the P-FET

and N-FET are designed to have the same impedance and

can provide peak currents of over 2 amps. In the MOSFET

gate-driver circuits, the output of the driver can swing from 0

to 9V~12V on P

output swings from 0V to –5V on the DMPO pin. HV732 can

generate ±100V NRZ, RZ and PW pulses and low voltage

CW waveforms. The up frequency limit of this IC is as high

as 35MHz to 40MHz dependent on the load capacitance.

Designing a Pulser with HV732

This demo board data sheet describes how to use the

HV732DB1 to generate the basic high voltage pulses for an

ultrasound transmitter with a RTZ feature.

The HV732 circuit uses the capacitor-coupling method in its

level translators, except for the one driving the N-channel

damping MOSFET, which is DC coupled. There are three

10nF 200V ceramic capacitors connecting the driver output

to the MOSFET’s gate for the coupling purposes.

The input stage of the HV732 has high-speed level

translators that are able to operate with logic signals of 1.8V,

2.5V or 3.3V. In this demo board, the control logic signals

are connected to a high-speed ribbon cable connector. The

control signal logic-high voltage should be same as the V

CC

voltage of the demo board, and the logic-low should be

referenced to GND.

The HV732DB1 output waveforms can be displayed using

an oscilloscope directly by connecting the scope probe to

the test point HV

select whether or not to connect the on-board equivalent-

load, a 220pF, 200V capacitor, parallel with a 1kΩ, 1W

resistor. A coaxial cable can also be used to connect the

user’s transducer to be driven and evaluated with this HV732

transmitter pulser directly and easily.

Logic

Control

0 to -100V

HV

OUT

C

L

R

L

1K

220pF

HV

OUT

Supertex

Supertex

HV732

HV732

RGND

P

RGND

N

OUT

P

OUT

N

TX

N

TX

P

V

PP

V

SUB

P

GATE

P

DR

V

DD

AV

DD

V

LL

EN

P

IN

N

IN

DAMP

CLAMP

V

LN

AGND GND

N

DR

N

GATE

DMPO DMPI

V

NN

-5.0V

0 to -100V

+100V

+9.0V to 12V

+1.8V to 3.3V

Schematic Block Diagram

High Speed ±100V 2A

Integrated Ultrasound Pulser Demo Board

Introduction