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I am trying to make a switch with an IGBT STGP19NC60HD. Here is a link to the data sheet. My simple circuit looks like this:

schematic

simulate this circuit – Schematic created using CircuitLab

Im sorry for not using the right symbol as the transistor, I did not see an IGBT symbol. I just want the voltage at the gate to turn the switch on and off. I have a 0-15V signal at the gate and some arbitrary signal at the collector - lets just say it is a 0-2V sine wave. When the gate voltage is 0V I expect the emitter voltage to be 0V. When I make the gate voltage 15V I want my sine wave to pass through to the emitter. In other words, I am trying to turn my sine wave on and off with a 0-15V logic signal at the gate. This works with a simple 2n222 transistor but not with the IGBT. With the IGBT I just get little upward spikes on the rising edge of the gate switch and downward spikes on the falling edge, but the sine wave does not pass through. Why not? Can I use an IGBT to make a simple switch like this?

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  • \$\begingroup\$ What load do you have on the emitter? How are you coupling the signal to the collector and precisely what is the signal you are using on the collector including any dc offset levels? \$\endgroup\$ – Andy aka Nov 29 '13 at 18:00
  • \$\begingroup\$ You are best off selecting a different device. Maybe an analog switch, a transmission gate, or perhaps some discrete mosfets. If this is an audio application, you can search for voltage controlled amplifiers if you would like finer amplitude control. \$\endgroup\$ – HL-SDK Nov 29 '13 at 19:21
  • \$\begingroup\$ My emitter is attached to a 50 ohm load. It is the signal input to a high voltage driver for an EOM (Electro Optic Modulator). I need to give it a unique voltage waveform that lasts ~20 ms and that is switched on/off with 100 ns, 1 MHz pulses. So I am trying to input the voltage waveform at the collector and switch it on/off with a TTL signal from this electronic pulse generator: quantumcomposers.com/products/pulse-generator/9530-series \$\endgroup\$ – user31351 Nov 29 '13 at 21:18
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    \$\begingroup\$ Apart from the symbol being incorrect - which you have explained - your diagram does not seem to come close to matching your actual circuit or application. eg "My emitter is attached to a 50 ohm load." -?> Please show actual and complete circuit | And, why use an IGBT? A MOSFET may well be as good or better for your task. \$\endgroup\$ – Russell McMahon Nov 30 '13 at 10:07
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1) you have a gate resistor of 1k when the datasheet is cited for 10R (for datasheet-like results)

2) you are putting a 2V signal on the collector of a 600V device whose Vce_sat is ... 2V

IGBT's are funny devices, their actual characteristics do not manifest themselves until you get reasonable voltage across then and reasonable voltage. A typical 3rd Gen 1200V IGBT at work will not switch fast enough or completely until it has at least 50V across it.

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  • \$\begingroup\$ So I guess this device needs to be used in the Volt/Amp range and not the Volt/milliamp range. Could I use this to switch on/off regular AC devices like christmas lights? \$\endgroup\$ – user31351 Nov 29 '13 at 22:47
  • \$\begingroup\$ To switch off an AC device with an IGBT you'll need a reverse-blocking IGBT. Most IGBTs either have integrated antiparallel diodes, or have no reverse-bias rating. An SCR might be more appropriate for that task. \$\endgroup\$ – Stephen Collings Jan 29 '14 at 1:48

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