MD0101 features ? up to 100v input voltage protection ? low on resistance - 15 typical ? integrated clamp diodes ? fast switching speed ? four electrically isolated channels ? no external supplies needed applications ? medical ultrasound imaging ? ndt applications ? fast resettable fuses ? high side switches ? data acquisition general description 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 r gnd . the analog switch terminals are tx and rx. rx has integrated clamping diodes to r gnd to protect the receiver against high voltages. voltages greater than 0.6v will start forward biasing the clamp diodes to r gnd . the MD0101 can be considered as a normally closed switch with a typical switch resistance of 15, 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, 200a, is allowed to fow through. 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 18- lead, 5x5mm dfn package as a four channel device for high density requirements. typical application circuit high voltage protection t/r switch with clamp diodes t ransmitter piezo t ransducers rx tx receiver tx rx high voltag e switches +90v -90v t/r switch MD0101 logic control and signal processing one of 128 channels rgnd supertex inc. supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
2 MD0101 absolute maximum ratings 1 -g indicates package is rohs compliant (green) ordering information device package option 18-lead dfn 5.00x5.00mm body 1.00mm height (max) 0.50mm pitch MD0101 MD0101k6-g pin confguration product marking 18-lead dfn (k6) (top view) (pad is at bottom of device) package may or may not include the following marks: si or 18-lead dfn (k6) parameter value v tx - v rx , differential voltage drop 0 to 110v maximum junction temperature +125c storage temperature range -65c to 150c power dissipation, 18-lead dfn 2 1.6w 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 1 2 3 4 5 6 7 8 9 18 17 16 15 14 13 12 11 10 nc rx1 rgnd1 rx2 rgnd2 rx3 rgnd3 rx4 rgnd4 nc tx1 nc tx2 nc tx3 nc tx4 nc MD0101 llllll 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 electrical characteristics (t j = 25oc, unless otherwise specifed) sym parameter min typ max units conditions bv tx-rx breakdown voltage from tx to rx 100 - - v i tx-rx = 500a r sw switch on resistance from tx to rx - 15 - i tx-rx = 5.0ma v trip v tx - rx trip point to turn off - 1.0 2.0 v --- v off switch turn off voltage - 2.0 - v i tx-rx = 1.0ma i a-b(off) switch off current - 200 300 a v tx-rx = 100v i peak peak switching current - 60 - ma --- t off turn off time - - 20 ns --- t on turn on time - - 20 ns --- c tx(on) switch on capacitance from tx to rx - 15 - pf sw = on c tx(off) switch off capacitance from tx to rx - 9.0 - pf v tx-rx = 25v bw small signal bandwidth - 100 - mhz r load t j operating junction temperature -40 - +125 c --- v rx diode forward voltage drop - 1.6 - v i rx = 200ma, rgnd = 0v, tx = open c d rx capacitance to rgnd - 20 - pf rgnd = 0v, tx = open esd sensitive devic e e supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
3 MD0101 block diagram switch control tx rx rgnd typical i-v characteristics i tx - rx -v off -v trip +100v i tx - rx = -200a -100v i tx - rx = +200a v tx - rx r sw = 15 +i peak -i peak +v trip +v off +1.0ma +1.0ma 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 fow - ing through the t/r switch, 200a, to detect if the high volt - age 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 fow 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 foating. the external diodes can then be connected to rx to ground. 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 r on is typi- cally 15. 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. supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
4 MD0101 switch capacitance the typical switch on capacitance, c sw(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 c tx(off) is about 11 - 6.5pf for 10 - 90v of the transmit voltage. please see figure 1 for the c-v curve of the c tx(off) . figure 1: c tx-rx vs v tx-rx t on and t off time the t on and t off of the MD0101 are less than 20ns, which provide a fast switch between the transmit mode and the receive mode. the t on and t off are input rise/fall time de- pendent. 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 t off and t on set ups are shown in figure 2 and figure 5 respectively. figure 2: test set up for t off figure 3: t off timing diagram figure 4: t off at v tx = 10v figure 4 shows the actual waveform and measurement of the t off . the t off is measured from 2.0v of the v tx to 10% of the v rx . figure 5: test set up for t on tx +10v 0v 10 transmitter rx tx 500ns rgnd (floating or connect to rx) md010 1 v tx v rx +10v +2v 10% tx transmitter 2.0v 0v 15 rx tx rgnd (floating or connect to rx) md010 1 +10v 500ns 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 01 02 03 04 05 06 07 08 09 0 100 v tx-rx c tx-rx (pf) supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
5 MD0101 figure 6: t on timing diagram figure 7: t on at v tx = 10v figure 7 shows the actual waveform and measurement of the t on . the t on is measured from 2.0v of the v tx to 1.0v of the v rx . figure 8: rx clamp diodes to rgnd v tx v rx +10v 0v 2v 1v 0v +2v 1v i-v curve 0 50 100 150 200 250 300 350 400 450 500 0. 00 0. 25 0. 50 0. 75 1. 00 1. 25 1. 50 1. 75 2. 00 2. 25 v f (v) i f (ma) supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
6 MD0101 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 clamp diode ground for transmit/receive switch 4 11 rx4 receiver side for transmit/receive switch 4 12 rgnd3 clamp diode ground for transmit/receive switch 3 13 rx3 receiver side for transmit/receive switch 3 14 rgnd2 clamp diode ground for transmit/receive switch 2 15 rx2 receiver side for transmit/receive switch 2 16 rgnd1 clamp diode ground for transmit/receive switch 1 17 rx1 receiver side for transmit/receive switch 1 18 nc no internal connection center tab --- connect to ground pin description supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
7 MD0101 (the package drawing(s) in this data sheet may not refect the most current specifcations. for the latest package outline information go to http://www.supertex.com/packaging.html .) doc.# dsfp-MD0101 b080211 18-lead dfn package outline (k6) 5.00x5.00mm body, 1.00mm height (max), 0.50mm pitch symbol a a1 a3 b d d2 e e2 e l l1 dimension (mm) min 0.80 0.00 0.20 ref 0.18 4.85* 4.20 ? 4.85* 3.50 ? 0.50 bsc 0.30 ? 0.00* 0 o nom 0.90 0.02 0.25 5.00 4.35 ? 5.00 3.65 ? 0.40 ? - - max 1.00 0.05 0.30 5.15* 4.45 ? 5.15* 3.75 ? 0.50 ? 0.15 14 o jedec registration mo-229, variation vjjd-2, issue c, aug 2003. * this dimension is not specifed in the jedec drawing. ? this dimension differs from the jedec drawing. drawings not to scale. supertex doc. #: dspd-18dfnk65x5p050, version a013111. notes: 1. a pin 1 identifer must be located in the index area indicated. the pin 1 identifer can be: a molded mark/identifer; 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. seating plane t op vi ew side v iew bottom v iew a a1 d e d2 e b e2 a3 l l1 v iew b vi ew b 1 note 3 note 2 note 1 (index area d/2 x e/2) note 1 (index area d/2 x e/2) 1 supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such appl ications 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) ?201 1 supertex inc. a ll rights reserved. unauthorized use or reproduction is prohibited. supertex inc. 1235 bordeaux drive, sunnyvale, ca 94089 t el: 408-222-8888 www .supertex.com
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