SKYPER

9

2011-04-04 – Rev05

© by SEMIKRON

3.5.

Power supply - Primary

Requirements of the auxiliary power supply

Regulated power supply

+15V ±4%

Maximum rise time of auxiliary power supply

150ms

Power on reset completed after

56ms

The same power supply used for SKYPER 32 can be taken

The supplying switched mode power supply may not be turned-off for a short time as consequence of

its current limitation. Its output characteristic needs to be considered. Switched mode power supplies

with fold-back characteristic or hiccup-mode can create problems if no sufficient over current margin is

available. The voltage has to rise continuously.

If the power supply is able to provide a higher current, a peak current will flow in the first instant to

charge up the input capacitances on the driver. Its peak current value will be limited by the power

supply and the effective impedances (e.g. distribution lines), only.

The driver error signal PRIM_nERROR_OUT is operational after 56ms. Without any error present, the

error signal will be reset.

To assure a high level of system safety the TOP and BOT signal inputs should stay in a defined state

(OFF state, LOW) during driver turn-on time. Only after the end of the power-on-reset, IGBT switching

operation shall be permitted.

3.6.

Gate driver signals – Primary

The signal transfer to each IGBT is made with pulse transformers, used for switching on and switching off of the

IGBT. The inputs have a Schmitt Trigger characteristic and a positive / active high logic (input HIGH = IGBT on;

input LOW = IGBT off).

It is mandatory to use circuits which switch active to +15V and 0V. Pull up and open collector output stages

must not be used for TOP / BOT control signals. It is recommended choosing the line drivers according to the

demanded length of the signal lines. The duty cycle of the driver can be adjusted between 0 – 100%. It is not

permitted to apply switching pulses shorter than 1µs.

TOP / BOT Input

A capacitor is connected to the input

to obtain high noise immunity. This

capacitor

can

cause

for

current

limited line drivers a little delay of few

ns, which can be neglected. The

capacitors have to be placed as

close

as

possible

to the

driver

interface.

Please note:

Do not apply switching

signals during power on

reset.