mandates apply for the level of isolation required (basic, supplementary, reinforced), operating voltage, pollution degree, overvoltage category, and altitude. For these reasons, only gate- drive DC/DC converters with suitable design and materials are recognized or are pending recognition to UL60950-1 for various basic and reinforced levels of protection (and which are generally equivalent to those in EN 62477-1:2012); more stringent recognition is also in place or pending to medical standard ANSI/ AAMI ES60601-1 with 1 × Means of Patient Protection (MOPP) and 2 × Means of Operator Protection (MOOP) requirements. ■ Common-mode transient immunity: CMTI is an important gate-driver parameter at higher switching frequencies where the gate driver has a differential voltage between two separate ground references, as is the case for isolated gate drivers. CMTI is defined as the maximum tolerable rate of rise or fall of the common- mode voltage applied between two isolated circuits and is specified in kV/µs or volts per nanosecond (V/ns). Having a high CMTI means that the two sides of an isolated arrangement—the transmit
Figure 9: All units in the Murata MGJ2 series of DC/DC converters have the same outward appearance and size, but they are available with a variety of input voltage ratings and bipolar output voltage pairings. (Image source: Murata Power Solutions)
side and receive side—exceed the datasheet specifications when “striking” the insulation barrier with a signal having a very high rise (positive) or fall (negative) slew rate. The DC/ DC converter datasheet should have a specification value for this parameter, and designers need to match it to the specifics of the operating frequency and voltage of their circuit. Meeting the gate-driver DC/ DC converter requirements Recognizing the many challenging and often conflicting demands on gate-drive DC/DC converters,
Murata has extended their MGJ2 series of through-hole DC/DC converters to include SMD DC/ DC units. Their converters are well suited to powering the high-side and low-side gate-drive circuits of IGBTs and MOSFETs in space- and weight-constrained applications due to their performance, compact form factor and low profile (approximately 20 millimeters (mm) long × 15 mm wide × 4 mm high), and compatibility with SMD manufacturing processes (Figure 9). The members of this family of 2-watt converters operate from
nominal inputs of 5, 12, and 15 volts, and offer a choice of asymmetric output voltages
we get technical
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