3 several thousand volts of isolation can be built in

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Unformatted text preview: m primary side to the secondary side. 3. Several thousand volts of isolation can be built in between windings by proper design and layouts. The disadvantages of using transformers for Gate Drive are: 1. They can be used only for time varying signals. 2. It is difficult to implement DESAT protection feature. Two examples of gate Drive circuits, using transformers follow. In Fig. (11), a phase shift controller outputs its signals to the IXD_404 Dual Drivers, which in-turn, feed the transformers. The secondary windings of these transformers are coupled to the Gates of upper and lower MOSFETs IXAN0009 in an “H” Bridge topology. Fig. (14) shows another transformer coupled Gate Drive circuit employing DC restore technique to maintain same wave shape of original signal with added feature of -ve bias offered using a Zener in series with a fast diode across secondary. 4.0 DESIRABLE SPECIFICATIONS AND FEATURES OF ANY LOW AND HIGH SIDE DRIVER PAIRS, SUCH AS IXBD4410 AND IXBD4411 1. Under voltage and over voltage lockout protection for Vcc ; 2. dV /dt immunity of greater than ± 50 V/ns; 3. Galvanic isolation of 1200 Volts (or greater) between low side and high side; 4. On-chip negative gate-drive supply to ensure MOSFET/IGBT turn-off even in electrically noisy environments; 5. CMOS/HCMOS compatible inputs with hysteresis; 6. < 20 ns rise and fall times with 1000 pf load and <100 ns rise and fall times with 10000 pf load; 7. <100 ns of propagation delay; 8. >2 Ampere peak output Drive Capability; 9. Automatic shutdown of output in response to over current and/or short -circuit; 10. Protection against cross conduction between upper and lower MOSFET/IGBT; 11. Logic compatible fault indication from both low and high-side drivers. A suggested wiring diagram, making use of such a high/low side driver pair is shown in Fig. (4). This diagram is for a phase leg of MOSFETs or IGBTs. Likewise, the wiring diagram is to be repeated for each phase leg and hence one needs two such circuits for “H” Bridge and three such circuits for 3-Phase Bridge topologies As can be seen in this schematic, to obtain galvanic isolation, it uses one ferrite core transformer for sending drive signals to IXBD4411 and another ferrite core tran...
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This note was uploaded on 01/15/2014 for the course ECE 624 taught by Professor Staff during the Winter '08 term at Ohio State.

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