EVAL-1EDI60I12AF中文資料英飛凌數(shù)據(jù)手冊PDF規(guī)格書

3.1 +5V and +15V supply voltages

The driver’s high side voltage has to be supplied externally. The 5V supply voltage, required for on board

circuits, is generated internally by an Infineon voltage regulator. The evaluation board does not provide an over

voltage supply monitoring, therefore the user has to ensure, that the voltages remain within the correct range.

Voltages exceeding the maximum values may lead to damage of the IGBT drivers and other circuitries.

The +5V supply is generated on the board by using the Infineon voltage regulator TLE4264G. The regulator is

used to supply input as well as output circuits of the evaluation board. In case a complete input to output

separation is required, the supply voltage must be provided externally.

The availability of the supply voltages is individually indicated for both power supplies via the green status

LEDs. For proper operation of the evaluation board, care has to be taken that both power supplies are available

and stable.

The output part of the high-side gate driver is supplied by bootstrap using an external ultra-fast diode. To ensure

that the bootstrap capacitor is charged before the high side IGBT is switched on, the low side IGBT has to be

switched on for at least 250μs.

3.2 Under voltage lockout

The +15V supply as well as the +5V supply are monitored by the 1EDI60I12AF gate drivers. In case of an under

voltage, the driver’s output is switched off until both input voltages are higher than the required thresholds.

The thresholds for the +5V supply typically are VCCUV+ = 2.85 V on a positive slope and VCCUV– = 2.75 V on a

negative slope.

The thresholds for the +15V supply typically are VBSUV+ = 12 V on a positive slope and

VBSUV– = 11.1 V on a negative slope.

3.3 Short circuit detection

The 1EDI60I12AF evaluation board provides short circuit detection by measuring the voltage drop across a

5mΩ shunt as depicted in Figure 3-1. This voltage drop is compared to a fixed voltage level of 254.5mV by the

comparator circuit sketched in Figure 3-2. If the current reaches a value of typ. 50A, a short circuit is detected

and the gate driver inputs HIN and LIN are disabled. IN? inputs are pulled high which means that PWM signals

at IN+ have no effect and the driver outputs are switched off. This state is reported by the OC LED. The OC

event is latched by the on-board flip-flop circuit as given in Figure 3-3 and must be reset by switching the

RESET signal to ground. As can be seen in Figure 3-2, the fault signal is fed from the output part of the board to

the input part utilizing an optocoupler. This allows operating the over-current protection circuit even if the input

to output separation of the board is used.

The experiment reveals a delay of approximately 2.8μs between the overcurrent detection and the output being

switch off. During this delay time, the current continues to rise until the IGBT switches off. Depending on the

inductance of the short circuit loop, the current may rise to rather high values which should be considered when

using the test board in connection with sensitive loads, respectively other external circuits.

3.4 Current sense amplifier

The EVAL-1EDI60I12AF provides an operational amplifier which amplifies the voltage drop across the shunt

with a gain of 11. The amplified voltage is available to the user at connector X1 pins A9 and B9. Figure 3-5

holds the schematic details of the amplifier setup.

3.5 IGBT turn ? on / off

The 1EDI60I12AF provides separate driver source output and driver sink output signals. These allow

independent control of IGBT turn-on respectively turn-off behavior. It can be seen in Figure 3-1Figure 3-7 that

the evaluation board is equipped with independent gate resistors RG1B, RG1T, RG2B and RG2T. The resistors

used in default configuration have a value of 27?. The values can be modified by the user in order to obtain a

required switching behavior. It should be noted that the deviation from the default values may result in increased

switching noise or higher switching losses. Examples of switching transients with default gate resistors

determined in a double pulse test are depicted in Figure 3-7.

3.6 DC-Link capacitors

The evaluation board provides a split DC-Link capacitor in order to enable connection of loads which require ac

voltages and bi-directional currents. In such a case, the load can be connected between HB_OUT and C_OUT

output which enables voltage inversion across the load. An example of possible bi-directional waveforms is

displayed in Figure 3-9. It should be noted, that in case of operation with bi-directional currents, the current

amplifier output only provides information about the current through the low-side IGBT. In addition to that, the

overcurrent protection circuit may not work properly in case of large negative current shifts. In case of

symmetrical current waveforms, the overcurrent protection should not be affected but it should be noted that an

overcurrent would be detected only on the positive part of the current waveform.

Due to the available space, only rather small DC-Link capacitors of 330nF are available on the board. If a larger

DC-Link capacity is necessary, it has to be connected to the connectors V+HV, GND_HV and C_OUT

externally.

3.7 Input PWM-Signals

There is a possibility to use low-pass filters inside the PWM input signals to avoid a turn-on of an IGBT by noise.

This feature is not used in this evaluation board due to internal signal filtering of the driver’s inputs which are

sufficient in most applications. However, there is the possibility to test this feature by changing the resistors

RIN1T, RIN1B and using a suitable capacitance value for the capacitors CIN1T, CIN1B as seen in Figure 3-10.

3.8 Separation between input and output side

The 1EDI60I12AF gate driver offers an input to output isolation capability of 1200V. The evaluation board takes

advantage of this feature by offering a possibility of input to output separation. This can be done by removing

the jumpers marked JP4 on the board as indicated in Figure 3-11. This removes all conductive connections

between the input and output side and therefore completely separates the two sides. This procedure also opens

the connection between the 5V onboard voltage regulator and the input side circuits. Thus, the +5V for the input

side must be supplied from an external, isolated source. In addition to that, the removal of the jumpers opens

the connection between the current amplifier output and the connector X1 and therefore the information about

the current is not available in case of isolated operation. The overcurrent protection remains functional since the

fault signal is fed back to the input side via an optocoupler.

It should be noted that in case of operation without this separation and all jumpers in place, the board requires

the +15V supply only.