Supertex inc.
MD1822DB1
MD1822 + TC7920: Three Level
High Speed ±100V 2.0A Pulser Demoboard
Demoboard Features
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Ultrasound high voltage & high current RTZ pulser
MD1822 driving TC7920 with two pairs of MOSFETs
3-level voltage pulse waveform outputs
±2.0A source and sink current capability
40 MHz frequency clock on board
Programmable logic waveform generation
JTAG connection for CPLD programming
Connectors for external clock and signals
3.3V CMOS logic interface
General Description
The MD1822DB1 is a demoboard for the three level ±100V
2.5A pulser chip-set of the MD1822 MOSFET driver and the
TC7920 MOSFET. The demoboard consists of one MD1822
in the 3x3mm 16-lead QFN package driving the TC7920
which has two pairs of high speed and high voltage compli-
mentary P- and N-MOSFETs in in one 4x4mm, 8-lead DFN
package. This circuit is an ideal, cost-optimized, high voltage
and high current RTZ ultrasound transmit pulser.
The CPLD-programmable logic circuit (40 MHz crystal os-
cillator) generates accurately timed high-speed waveforms
on a separate CPL board. Multiple frequency and waveform
combinations can be selected as bipolar pulse waveforms.
An external clock input can be used if the on-board oscil-
lator is disabled. The external trigger input can be used to
synchronize the output waveforms. There are five push
buttons for selecting demonstration waveform, frequency,
phase, and mode functions. Color LEDs indicate the demo
selection states. Jumpers on the board can select either the
330pF/2.5k on-board load, or user test loads.
Applications
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Medical ultrasound imaging
Piezoelectric transducer drivers
Material flaw detection
ATE and waveform generator
Transducer power driver
Capacitive and MEMS sensor driver
Ultrasonic NDT detection and sonar ranger
Block Diagram
+3.3V
JTAG
+12V
6
VDD/VH
+100V
V
PP
PE
EXTRG
EXCLK
40MHz
INC
OSC
EN
CLK
IN
Waveform
Generator
CPLD
IND
-100V
V
NN
XDCR
X1
EXT
INA
INB
C
L
330pF
VSS/VL
R
L
2.5k
5
WAVE
FREQ
SEL
CLMP
ENAB
LED1
LED2
PWR
ENA
MOD
TC7920
MD1822
Doc.# DSDB-MD1822DB1
A032913
Supertex inc.
www.supertex.com
MD1822DB1
MD1822DB1 Board and PCB Layout
Actual size = 100mm x 70mm
Operating Supply Voltages and Current
(on J10)
Symbol
V
CC
GND
V
DD
V
PP
V
NN
Parameter
Logic supply
Circuit ground or 0V
MD1822 positive supply
TC7920 HV positive supply
TC7920 HV negative supply
Min
1.8
-
5.0
0
-100
Typ
3.3
0
10
-
-
Max
3.3
-
11.5
100
0
Units
V
V
V
V
V
Suggested Current Limit *
150mA
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10mA
5.0mA
5.0mA
Note:
* Current limits should be changed according the testing waveform, frequency and duty cycles.
Push Button Operation Functions
Button Symbol
WAVE
FREQ
SEL
ENA
PHASE
Description
Demo waveforms selection
Demo waveform frequency selection
Not Used
MD1822 PE pin control
Not Used
Doc.# DSDB-MD1822DB1
A032913
2
Supertex inc.
www.supertex.com
ARM技术
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