SUPERTEX MD0101

Supertex inc.
MD0101
High Voltage Protection T/R Switch
with Clamp Diodes
Features
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General Description
Up to ±100V input voltage protection
Low on resistance - 15Ω typical
Integrated clamp diodes
Fast switching speed
Four electrically isolated channels
No external supplies needed
Applications
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The Supertex MD0101 is a four channel, high voltage, current limiting
protection device. It is designed to protect a low noise receiver from the
high voltage transmit pulses in ultrasound applications and is commonly
referred to as a T/R (transmit and receive) switch. Each channel has
three terminals; Tx, Rx, and RGND. The analog switch terminals are
Tx and Rx. Rx has integrated clamping diodes to RGND to protect the
receiver against high voltages. Voltages greater than ±0.6V will start
forward biasing the clamp diodes to RGND.
The MD0101 can be considered as a normally closed switch with a
typical switch resistance of 15Ω, allowing small signals to pass. Once
the voltage drop across the switch exceeds a nominal value of ±1.0V,
the device will start to turn off. In the off state, the MD0101 can withstand
up to ±100V across its terminals. A small amount of current, 200µA, is
allowed to flow through.
Medical ultrasound imaging
NDT applications
Fast resettable fuses
High side switches
Data acquisition
The MD0101 is not limited to just ultrasound applications. It can also
be used for resettable fuses to protect power lines, output short circuit
protection, and data acquisition. The MD0101 is available in an 18Lead, 5x5mm DFN package as a four channel device for high density
requirements.
Typical Application Circuit
One of 128 Channels
+90V
Transmitter
Logic
Control
and
Signal
Processing
Piezo
Transducers
-90V
TX
RX
Receiver
RX
MD0101
TX
RGND
High Voltage
Switches
T/R Switch
Supertex inc.
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
MD0101
Pin Configuration
Ordering Information
Package Option
NC
18-Lead DFN
Device
5.00x5.00mm body
1.00mm height (max)
0.50mm pitch
Tx1 2
MD0101K6-G
Tx2 4
MD0101
NC
NC
-G indicates package is RoHS compliant (‘Green’)
18 NC
1
17 Rx1
16 RGND1
3
15 Rx2
14 RGND2
5
13 Rx3
Tx3 6
NC
12 RGND3
7
11 Rx4
Tx4 8
NC
ESD Sensitive Device
E
10 RGND4
9
Absolute Maximum Ratings1
18-Lead DFN (K6)
Parameter
(top view)
(Pad is at bottom of device)
Value
VTX - VRX, Differential voltage drop
0 to ±110V
Maximum junction temperature
+125°C
Storage temperature range
Product Marking
MD0101
LLLLLL
-65°C to 150°C
1.6W
Power dissipation, 18-Lead DFN2
1.
Absolute Maximum Ratings are those values beyond which damage to
the device may occur. Functional operation under these conditions is not
implied. Continuous operation of the device at the absolute rating level
may affect device reliability. All voltages are referenced to device ground.
2.
Mounted on FR4 board, 25mm x 25mm x 1.57mm
YYWW
AAACCC
L = Lot Number
YY = Last Digit of Year Sealed
WW = Code for Week Sealed
A = Assembler ID
C = Country of Origin
= “Green” Packaging
18-Lead DFN (K6)
Package may or may not include the following marks: Si or
Electrical Characteristics (T = 25ºC, unless otherwise specified)
J
Sym
BVTX-RX
Parameter
Min
Typ
Max
Units Conditions
Breakdown voltage from TX to RX
±100
-
-
V
ITX-RX = ±500µA
RSW
Switch ON resistance from TX to RX
-
15
-
Ω
ITX-RX = ±5.0mA
VTRIP
VTX - RX trip point to turn off
-
±1.0
±2.0
V
---
VOFF
Switch turn off voltage
-
±2.0
-
V
ITX-RX = ±1.0mA
Switch off current
-
±200
±300
µA
VTX-RX = ±100V
IPEAK
Peak switching current
-
±60
-
mA
---
TOFF
Turn off time
-
-
20
ns
---
TON
Turn on time
-
-
20
ns
---
CTX(ON)
Switch ON capacitance from TX to RX
-
15
-
pF
SW = ON
CTX(OFF)
Switch OFF capacitance from TX to RX
-
9.0
-
pF
VTX-RX = 25V
Small signal bandwidth
-
100
-
MHz
RLOAD = 50Ω
-40
-
+125
°C
---
IA-B(OFF)
BW
TJ
Operating junction temperature
VRX
Diode forward voltage drop
-
±1.6
-
V
IRX = ±200mA, RGND = 0V,
TX = Open
CD
RX capacitance to RGND
-
20
-
pF
RGND = 0V, TX = Open
Supertex inc.
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
2
MD0101
Block Diagram
TX
RX
RGND
Switch Control
Typical I-V Characteristics
+IPEAK
ITX - RX
ITX - RX = +200µA
-100V
-VOFF
+1.0mA
-VTRIP
+VTRIP
+VOFF
VTX - RX
+1.0mA
+100V
ITX - RX = -200µA
RSW = 15Ω
-IPEAK
Functional Description
The Supertex MD0101 can be considered a normally closed
switch, controlled by a switch control (please refer to the
block diagram). The switch control monitors the voltage
drop across terminals TX and RX. If the voltage difference
is greater than ±1.0V, the T/R switch will start to open. Once
in the open state, there is a small amount of current flowing through the T/R switch, 200µA, to detect if the high voltage is still present or not. The T/R switch will not close until
the voltage across terminals TX and RX drops below ±2.0V.
Connecting the RGND to ground will allow the initial peak
current, about 60mA, to flow through the switch then to the
clamp diodes to RGND. The clamp diode I-V Curve is shown
in Figure 8. If external diodes are desired, the RGND pin can
be connected to the corresponding RX pin or left floating.
The external diodes can then be connected to RX to ground.
Supertex inc.
The MD0101 does not require a power supply. There are
only three pins per channel; one connects to the transmitter
side, one connects to the receiver side, and the other one is
the ground connection for diodes.
On Resistance
When the voltage across terminals TX and RX is below
±1.0V, the switch is in the receive mode, and the RON is typically 15Ω. Once the voltage across the terminals TX and RX
is greater than ±2.0V, the switch is in the transmit mode and
blocks the high voltage pulses from passing through to the
receiver and damaging it.
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
3
MD0101
Switch Capacitance
The typical switch ON capacitance, CSW(ON), is 21pF. This is
measured from TX to RX when the switch is ON. The switch
OFF capacitance is a function of the voltage across the T/R
switch. The CTX(OFF) is about 11 - 6.5pF for 10 - 90V of the
transmit voltage. Please see Figure 1 for the C-V curve of
the CTX(OFF).
Figure 1: CTX-RX vs VTX-RX
Figure 3: TOFF Timing Diagram
+10V
VTX
+2V
10%
VRX
13.0
12.0
Figure 4: TOFF at VTX = 10V
CTX-RX (pF)
11.0
10.0
9.0
8.0
7.0
6.0
0
10
20
30
40
50
60
VTX-RX
70
80
90
100
TON and TOFF Time
The TON and TOFF of the MD0101 are less than 20ns, which
provide a fast switch between the transmit mode and the
receive mode. The TON and TOFF are input rise/fall time dependent. The T/R switch turns ON and OFF faster when the
rise and fall times of the transmit pulse are faster. On the
other hand, the switch turns ON and OFF slower if the rise
and fall times of the transmit pulse are slower. The TOFF and
TON set ups are shown in Figure 2 and Figure 5 respectively.
Figure 2: Test set up for TOFF
500ns
Transmitter
+10V
Figure 5: Test set up for TON
500ns
Transmitter
0V
TX
Figure 4 shows the actual waveform and measurement of
the TOFF. The TOFF is measured from 2.0V of the VTX to 10%
of the VRX.
0V
TX
RX
10Ω
TX
MD0101
RGND
(Floating or connect to RX)
+10V
2.0V
15Ω
RX
MD0101
TX
RGND
(Floating or connect to RX)
Supertex inc.
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
4
MD0101
Figure 6: TON Timing Diagram
VTX
Figure 8: RX Clamp Diodes to RGND
+10V
I-V Curve
500
450
+2V
400
0V
2V
If (mA)
VRX
350
1V
1V
300
250
200
150
100
50
0
0.00
0V
0.25
0.50
0.75
1.00
1.25
Vf (V)
1.50
1.75
Figure 7: TON at VTX = 10V
Figure 7 shows the actual waveform and measurement of
the TON. The TON is measured from 2.0V of the VTX to 1.0V of
the VRX.
Supertex inc.
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
5
2.00
2.25
MD0101
Pin Description
Pad
Name
Description
1
NC
No internal connection
2
TX1
Transmitter side of transmit/receive switch 1
3
NC
No internal connection
4
TX2
Transmitter side of transmit/receive switch 2
5
NC
No internal connection
6
TX3
Transmitter side of transmit/receive switch 3
7
NC
No internal connection
8
TX4
Transmitter side of transmit/receive switch 4
9
NC
No internal connection
10
RGND4
11
RX4
12
RGND3
13
RX3
14
RGND2
15
RX2
16
RGND1
17
RX1
Receiver side for transmit/receive switch 1
18
NC
No internal connection
Center Tab
---
Connect to ground
Clamp diode ground for transmit/receive switch 4
Receiver side for transmit/receive switch 4
Clamp diode ground for transmit/receive switch 3
Receiver side for transmit/receive switch 3
Clamp diode ground for transmit/receive switch 2
Receiver side for transmit/receive switch 2
Clamp diode ground for transmit/receive switch 1
Supertex inc.
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
6
MD0101
18-Lead DFN Package Outline (K6)
5.00x5.00mm body, 1.00mm height (max), 0.50mm pitch
D
Note 1
(Index Area
D/2 x E/2)
1
D2
1
Note 1
(Index Area
D/2 x E/2)
E
E2
e
b
Top View
View B
Bottom View
Note 3
θ
A
A3
A1
L
Seating
Plane
L1
Note 2
Side View
View B
Notes:
1. A Pin 1 identifier must be located in the index area indicated. The Pin 1 identifier can be: a molded mark/identifier; an embedded metal marker; or
a printed indicator.
2. Depending on the method of manufacturing, a maximum of 0.15mm pullback (L1) may be present.
3. The inner tip of the lead may be either rounded or square.
Symbol
Dimension
(mm)
A
A1
MIN
0.80
0.00
NOM
0.90
0.02
MAX
1.00
0.05
A3
0.20
REF
b
D
D2
E
E2
0.18
4.85*
4.20
4.85*
3.50
0.25
5.00
4.35†
5.00
3.65†
0.30
5.15*
4.45
5.15*
3.75
†
†
e
†
†
0.50
BSC
L
L1
θ
0.00*
0O
0.40†
-
-
0.50
0.15
14O
0.30
†
†
JEDEC Registration MO-229, Variation VJJD-2, Issue C, Aug 2003.
* This dimension is not specified in the JEDEC drawing.
† This dimension differs from the JEDEC drawing.
Drawings not to scale.
Supertex Doc. #: DSPD-18DFNK65X5P050, Version A013111.
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline
information go to http://www.supertex.com/packaging.html.)
Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives
an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability
to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and
specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//www.supertex.com)
Supertex inc.
©2011 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited.
Doc.# DSFP-MD0101
B080211
7
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com