Datasheet 2ED2106 (4) S06F (J) (Infineon) - 12

link to page 12 link to page 12 2ED2106 (4) S06F (J) 650 V high-side and low-side gate driver with integrated bootstrap diode The low ohmic current limiting resistor provides essential advantages over other competitor devices with high ohmic bootstrap structures. A low ohmic resistor such as in the 2ED210x family allows faster recharching of the bootstrap capacitor during periods of small duty cycles on the low side transistor. The bootstrap diode is a real pn-diode which works with all control algorithms of modern power electronics, such as trapezoidal or sinusoidal motor drives control. 5.7 Calculating the bootstrap capacitance CBS Bootstrapping is a common method of pumping charges from a low potential to a higher one. With this technique a supply voltage for the floating high side sections of the gate drive can be easily established according to Figure 13. This method has the advantage of being simple and low cost but may force some limitations on duty-cycle and on-time since they are limited by the requirement to refresh the charge in the bootstrap capacitor.Proper capacitor choice can reduce drastically these limitations. Figure 13 Half bridge bootstrap circuit in 2ED210x When the low side MOSFET turns on, it wil force the potential of pin VS to GND. The existing difference between the voltage of the bootstrap capacitor VCBS and VCC results in a charging current IBS into the capacitor CBS. The current IBS is a pulse current and therefore the ESR of the capacitor CBS must be very smal in order to avoid losses in the capacitor that result in lower lifetime of the capacitor. This pin is on high potential again after low side is turned off and high side is conducting current. But now the bootstrap diode DBS blocks a reverse current, so that the charges on the capacitor cannot flow back to the capacitor CVCC. The bootstrap diode DBS also takes over the blocking voltage between pin VB and VCC. The voltage of the bootstrap capacitor can now supply the high side gate drive sections. It is a general design rule for the location of bootstrap capacitors CBS, that they must be placed as close as possible to the IC. Otherwise, parasitic resistors and inductances may lead to voltage spikes, which may trigger the undervoltage lockout threshold of the individual high side driver section. However, all parts of the 2ED210x family, which have the UVLO also contain a filter at each supply section in order to actively avoid such undesired UVLO triggers. The current limiting resistor RBS according to Figure 13 reduces the peak of the pulse current during the low side MOSFET turn-on. The pulse current wil occur at each turn-on of the low side MOSFET, so that with increasing switching frequency the capacitor CBS is charged more frequently. Therefore a smal er capacitor is suitable at higher switching frequencies. The bootstrap capacitor is mainly discharged by two effects: The high side quiescent current and the gate charge of the high side MOSFET to be turned on. Datasheet 12 of 24 V 2.10 www.infineon.com/soi 2019-09-12 Document Outline Features Product summary Potential applications Product validation Ordering information Description 1 Table of contents 2 Block diagram 3 Pin configuration and functionality 3.1 Pin configuration 3.2 Pin functionality 4 Electrical parameters 4.1 Absolute maximum ratings 4.2 Recommended operating conditions 4.3 Static electrical characteristics 4.4 Dynamic electrical characteristics 5 Application information and additional details 5.1 IGBT / MOSFET gate drive 5.2 Switching and timing relationships 5.3 Matched propagation delays 5.4 Input logic compatibility 5.5 Undervoltage lockout 5.6 Bootstrap diode 5.7 Calculating the bootstrap capacitance CBS 5.8 Tolerant to negative tranisents on input pins 5.9 Negative voltage transient tolerance of VS pin 5.10 NTSOA – Negative Transient Safe Operating Area 5.11 Higher headroom for input to output signal transmission with logic operation upto -11 V 5.12 Maximum switching frequency 5.13 PCB layout tips 6 Qualification information0F 7 Related products 8 Package details 9 Part marking information 10 Additional documentation and resources 10.1 Infineon online forum resources 11 Revision history