HV758DB1
HV758 鹵90V 2.2A Ultrasound Pulser Demo Board
Introduction
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 鹵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鈥檚 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
鹵2.5A for pulsing, when MC0 = 1 and MC1 = 1, with up
to 鹵90V swings. When in mode 1, all the output stages
drop the peak current to 鹵580mA for low-voltage CW mode
operation to save power. Two 鏗俹ating 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.
Designing a Pulser with HV758
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
PP
and V
NN
rail voltages can be changed
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 2.5k惟, 1W
resistor. Also, a coaxial cable can be used to connect the
user鈥檚 transducer to easily drive and evaluate the HV758
transmitter pulser.
Typical Application Circuit
+1.8 to 3.3V
C1
V
LL
OTP
EN
MC0
MC1
PIN1
+1.8 to 3.3V
Logic
NIN1
EN_PWR
+10V
C2
V
DD
C3
+90V VPP-10V
C4
V
SUB
SUB
0 to +90V
C5
V
PP
V
PF
RGND
R
P1
P-Driver
TXP1
D1
HVout1
Level
Translator
Level
Translator
N-Driver
R
N1
TXN1
D2
X1
RGND
HV758
1 of 4 Channels
G
REF
V
SS
V
NF
C7
V
NN
+10V
V
NN
C6
0 to -90V
SUPERTEX
1
2
3
4
5
6
