HV758DB1 Datasheet, PDF (1/6 Pages) Supertex, Inc – HV758 ±90V 2.2A Ultrasound Pulser Demo Board

HV758DB1
HV758 ±90V 2.2A Ultrasound Pulser Demo Board
Introduction
Designing a Pulser with HV758
The HV758 is a monolithic 4-channel, high-speed, high
voltage, ultrasound transmitter pulser. This integrated, high
performance circuit is in a single, 8x8mm, 64-Ball FCBGA
package.
The HV758 can deliver up to a ±2.2A source and sink
current to a capacitive transducer. It is designed for
medical ultrasound imaging and ultrasound material NDT
applications. It can also be used as a high voltage driver
for other piezoelectric or capacitive MEMS transducers, or
for ATE systems and pulse signal generators as a signal
source.
HV758’s circuitry consists of controller logic circuits, level
translators, gate driving buffers and a high current and high
voltage MOSFET output stage. The output stages of each
channel are designed to provide peak output currents over
±2.5A for pulsing, when MC0 = 1 and MC1 = 1, with up
to ±90V swings. When in mode 1, all the output stages
drop the peak current to ±580mA for low-voltage CW mode
operation to save power. Two floating 9VDC power supplies
referenced to V_PP and V_NN supply the P- and N-type power
FET gate drivers. The upper limit frequency of the pulser
waveform is 20MHz depending on the load capacitance.
One HV758 can also be used as four damping circuits to
generate fast return-to-zero waveforms by working with
another HV758 as four pulsing circuits. It also has built-in,
under-voltage and over-temperature protection functions.
This demo board data sheet describes how to use the
HV758DB1 to generate the basic high voltage pulse
waveform as an ultrasound transmitting pulser.
The HV758 circuit uses the DC coupling method in all
level translators. There are no external coupling capacitors
needed. The V and V rail voltages can be changed
PP
NN
rather quickly, compared to a high voltage capacitor gate-
coupled driving pulser. This direct coupling topology of the
gate drivers not only saves two high voltage capacitors per
channel, but also makes the PCB layout easier.
The input stage of the HV758 has high-speed level
translators that are able to operate with logic signals of
1.2V to 5.0V and are optimized at 2.5V to 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 the same as the V_CC voltage
of the demo board, and the logic-low should be referenced
to GND.
The HV758DB1 output waveforms can be displayed using
an oscilloscope directly by connecting the scope probe to
the test point TX1 to 4 and GND. The soldering jumper can
select whether or not to connect the on-board equivalent-
load, a 330pF, 200V capacitor, parallel with a 2.5kΩ, 1W
resistor. Also, a coaxial cable can be used to connect the
user’s transducer to easily drive and evaluate the HV758
transmitter pulser.
Typical Application Circuit
+1.8 to 3.3V +10V
C1
C2
VLL
VDD
+90V VPP-10V 0 to +90V
C3
C4
VSUB VPF
C5
VPP
+1.8 to 3.3V
Logic
OTP
EN
MC0
MC1
PIN1
NIN1
EN_PWR
Level
Translator
SUB
P-Driver
RGND
R_P1
TXP1
D1
G_REF
Level
Translator
N-Driver
HV758
1 of 4 Channels
V_SS
V_NF
C7
R_N1
V_NN
C6
TXN1
D2
RGND
HVout1
X1
V_NN +10V 0 to -90V