SCALE™-2+ 2SC0435T
Preliminary Description & Application Manual
www.power.com/igbt-driver
Page 14
A resistor between GLx and COMx of 4.7kΩ (other values are also possible) may be used in order to provide a
low-impedance path from the IGBT/MOSFET gate to the emitter/source even if the driver is not supplied with
power. No static load (e.g. resistors) must be placed between GLx and the emitter terminal VEx.
Note however that it is not advisable to operate the power semiconductors within a half-bridge with a driver in
the event of a low supply voltage. Otherwise, a high rate of increase of V
CE
may cause partial turn-on of these
IGBTs.
How Do 2SC0435T SCALE-2+ Drivers Work in Detail?
Power supply and electrical isolation
The driver is equipped with a DC/DC converter to provide an electrically insulated power supply to the gate
driver circuitry. All transformers (DC/DC and signal transformers) feature safe isolation to EN 50178,
protection class II between primary side and either secondary side.
Note that the driver requires a stabilized supply voltage.
Power-supply monitoring
The driver’s primary side as well as both secondary-side driver channels are equipped with a local
undervoltage monitoring circuit.
In the event of a primary-side supply undervoltage, the power semiconductors are driven with a negative gate
voltage to keep them in the off-state (the driver is blocked) and the fault is transmitted to both outputs SO1
and SO2 until the fault disappears.
In case of a secondary-side supply undervoltage, the corresponding power semiconductor is driven with a
negative gate voltage to keep it in the off-state (the channel is blocked) and a fault condition is transmitted to
the corresponding SOx output. The SOx output is automatically reset (returning to a high impedance state)
after the blocking time.
