Hybrid Power IC Supplies Gate Drive for IGBT Modules

March 1, 2002
New from Powerex is the M57161L-01 hybrid gate driver IC for the company's 600V and 1200V F-Series IGBT modules. This single IC converts logic level input

New from Powerex is the M57161L-01 hybrid gate driver IC for the company's 600V and 1200V F-Series IGBT modules. This single IC converts logic level input control signals into ±7A gate drive with suitable on-and-off bias voltages. An integrated high-speed optocoupler isolates the input control signal from the rest of the circuit. Operating from a 15V input, a built-in isolated dc-dc converter supplies +17.4V and -6.5V for the gate drive circuits. Also included are short-circuit and undervoltage protection, as well as a fault status feedback signal.

F-Series (trench gate) IGBT modules have a built-in real time control (RTC) circuit that limits short-circuit current and maintains a 10µs short-circuit withstand capability. It does this by actively reducing the gate voltage in the presence of excessive collector current. The gate driver (Fig. 1) uses a gate voltage detection circuit to sense activation of the RTC circuit.

Activation of the module's RTC causes the gate driver to initiate a soft shutdown of the IGBT and start a timed lock-out — typically 2 ms. Soft turn-off limits any generated transient voltage and interrupts IGBT short-circuit current. During lockout, the gate driver produces a fault feedback signal and ignores all input signals. Normal operation resumes after lockout time expires and the control input signal returns to its off state.

This protection scheme avoids the need for a high voltage detection diode, reduces spacing requirements on the gate driver's p. c. board, and improves noise immunity.

There is a default short-circuit detection time delay of about 3.5µs, which prevents erroneous detection of short-circuit conditions as long as the series gate resistance (RG) is near the minimum recommended value for the module being used. Some low frequency applications may use a large Rg to slow the switching of the IGBT. In these cases, you can use the td adjust pin (28) to adjust the RTC detection time and total shut-down time. To extend the trip time, you can connect CTRIP as shown in Fig. 2. This capacitor should be located as close as possible to the pins of the gate driver.

Fig. 2 shows an example application circuit. The input circuit to the optocoupler includes a 390Ω resistor, which provides about 10mA to drive the optocoupler with a 5V input. Other input voltages require the addition of an external current limiting resistor.

The circuit operates from a 15V supply that must be decoupled with a capacitor closely connected to the driver's pins, providing a stable, well-filtered voltage for the primary side of the driver's built-in dc-dc converter.

To deliver an efficient pulse current, the output of the isolated dc-dc converter must be decoupled using a combination of low impedance electrolytic and film capacitors. These capacitors should be located as close as possible to the gate driver's pins.

Detecting a short circuit or undervoltage, pin 28 pulls down to the VEE supply. An optocoupler isolates the fault feedback signal by connecting the isolated power supply's common pin to the fault signal pin through a 470Ω resistor. If a fault occurs, about 10mA flows in the optocoupler.

For more information on this article, CIRCLE 349 on Reader Service Card

Sponsored Recommendations

TTI Transportation Resource Center

April 8, 2024
From sensors to vehicle electrification, from design to production, on-board and off-board a TTI Transportation Specialist will help you keep moving into the future. TTI has been...

Cornell Dubilier: Push EV Charging to Higher Productivity and Lower Recharge Times

April 8, 2024
Optimized for high efficiency power inverter/converter level 3 EV charging systems, CDE capacitors offer high capacitance values, low inductance (< 5 nH), high ripple current ...

TTI Hybrid & Electric Vehicles Line Card

April 8, 2024
Components for Infrastructure, Connectivity and On-board Systems TTI stocks the premier electrical components that hybrid and electric vehicle manufacturers and suppliers need...

Bourns: Automotive-Grade Components for the Rough Road Ahead

April 8, 2024
The electronics needed for transportation today is getting increasingly more demanding and sophisticated, requiring not only high quality components but those that interface well...


To join the conversation, and become an exclusive member of Electronic Design, create an account today!