|
|
I would like to drive an IGBT from a microcontroller (CMOS).
Is there a driver circuit that can outputs around +15v (on) and a -5v (off)
for switching frequencies around 40Khz.
I think -ve voltage supply is avaliable
What is this type of circuit called?
Surprisingly it is called a gate driver circuit. IGBTs imply large power
switching so that even though the switching frequency is a modest 40KHz,
the driver is still required to switch the device through ON/OFF
transitions quickly to reduce losses and component heating. Micrel at
http://www.micrel.com manufactures a line of powerful gate driver
products capable of handling nearly any situation. The most basic part
in their line-up is the MIC4120, a non-inverting driver capable of
supporting 6A peak gate drive currents. A high speed interface to a
microcontroller might look like this:
View in a fixed-width font such as Courier.
.
.
. CMOS>-[1.5K]-+-[10K]-+ +15V
. | | |
. >| | |
. BC557 |-----+ +-----+-------+---------+
. /| | | | | MIC4120 |
. | --- | | ----------- |
. | /// | 0.1u| | 1,8 | |0.1u
. | | === | |\ | ===
. | | | |2 | \ 6,7| |
. +---------------------|---| >----|----[10]-> To
. | | | | | / | |
. | |1u | | |/ | | IGBT GATE
. [1.2K] === | | 4,5 | |
. | | | ----------- |
. | | | | |
. +------------+-----+-------+---------+
. |
. |
. -5V
.
.
|
|