SKYPER™ 32 R

8

2007-01-19 – Rev05

© by SEMIKRON

Isolation Test Voltage

The isolation test voltage represents a measure of immunity to transient voltages. The maximum test voltage and time

applied once between input and output, and once between output 1 and output 2 are indicated in the absolute maximum

ratings. The high-voltage isolation tests and repeated tests of an isolation barrier can degrade isolation capability due to

partial discharge. Repeated isolation voltage tests should be performed with reduced voltage. The test voltage must be

reduced by 20% for each repeated test.

The isolation of the isolation barrier (transformer) is checked in the part. With exception of the isolation barrier, no active

parts, which could break through are used. An isolation test is not performed as a series test. Therefore, the user can

perform once the isolation test with voltage and time indicated in the absolute maximum ratings.

Auxiliary Power Supply

A few basic rules should be followed when dimensioning the customer side power supply for the driver. The following table

shows the required features of an appropriate power supply.

Requirements of the auxiliary power supply

Regulated power supply

+15V ±4%

Maximum rise time of auxiliary power supply

50ms

Minimum peak current of auxiliary supply

1A

Power on reset completed after

150ms

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 and without any

plateau formation as shown in the following diagram.

Rising slope of the power supply voltage

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.

It is recommended to avoid the paralleling of several customer side power supply units. Their different set current limitations

may lead to dips in the supply voltage.

The driver is ready for operation typically 150ms after turning on the supply voltage. The driver error signal

PRIM_nERROR_OUT is operational after this time. 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.

Please note:

Do not apply switching

signals during power on

reset.

Please note:

An isolation test is not performed at SEMIKRON as a series test.