Supertex inc.

Supertex inc.

www.supertex.com

MD2131

Doc.# DSFP-MD2131

C102412

Features

Applications

focus scanning

generator

General Description

The MD2131 is a high-speed, arbitrary waveform, push-pull

source driver. It is designed for medical ultrasound imaging and

HIFU beamforming applications. It also can be used in NDT,

Sonar and other ultrasound phase-array focusing beamforming

applications.

The MD2131 consists of CMOS digital logic input circuits, an

8-bit current DAC for waveform amplitude control, and four PWM

current-sources. These current sources are constructed with the

high-speed, in-phase and quadrature current-switch matrix and

the built-in sine and cosine angle-to-vector look-up table. The

range of 48 steps. There are four logic input signals to control the

in-phase and quadrature PWM push-pull current-source’s output

timing, frequency, cycle in the burst and waveform envelope.

The MD2131’s output stage is designed to drive two DN2625

depletion N-type MOSFETs. The MOSFET drains are connected

to a center-tap ultrasound frequency pulse transformer. The

secondary winding of the transformer can connect to the

ultrasound piezo or capacitive transducer via a cable with a

good impendence match. The MD2131 has a high-speed, SPI-

compatible interface to achieve per-scan-line fast updating of the

data register for changing the beamforming phase angles and

apodization amplitudes.

MD2131 Block Diagram

High Speed Ultrasound Beamforming Source Driver

+5.0V

I

Q

A

DGND

AGND

C3A

KA

C1A

C3B

C2B

C1B

VREF

IA

QA

IB

QB

EN

SDI

SDO

SCK

CS

LD

VLL

SUB

VDD

+5.0V

+2.5V

PA

XDRC

DN2625

PB

T1

+3.3V

+70-100V

V

PP

GND

KB

C2A

RFB

Data

Latch

&

Control

Logic

Level

Translator

DAC

Vector

Beamforming

Switch

Matrix

D1

D2

DN2625

+3.3V

+5.0V

SIN/COS

Table

&

Level

Translator