FL3100TSX Integrated Circuits (ICs)

FL3100TSX Application Field and Working Principle

The FL3100TSX is a high-performance gate driver PMIC with a maximum operating voltage of 40 V and includes sophisticated startup, fault-tolerant and monitoring interface functions.

This gate driver PMIC is a high-performance, low-power substitute for existing gate drivers. It features an internal soft start Ramp generator, overvoltage protection, overcurrent protection, temperature-independent gate driver biasing and adjustable fault-tolerance in addition to the standard features such as high peak gate current, fast rise times, short propagation delays and active pull down.

Field of Application

The FL3100TSX is a cost effective polymer type of gate driver intended for high drive applications such as IGBT and MOSFET gate drives, photovoltaic power conditioning, standalone or driver paralleled power module applications, or micro-inverter products. The FL3100TSX can also be used in battery packs, from e-scooters and e-bikes to connected electric vehicles.

Working Principle of the FL3100TSX

The FL3100TSX operates in open loop mode and utilizes an external PWM signal as an input. The high-side half bridge device is enabled when the input PWM signal is switched to the high-voltage output. When the PWM signal is deactivated, the high-side device will be disabled and the low-side device will remain is enabled until the PWM signal is re-activated. The output of the device can be switched either directly or through an optocoupler. A built-in charge pump enables the maximum safe operation of the high-side device in open loop operation.

Once the PWM signal is active, the built-in V/I control ramp generator sets the output voltage of the FL3100TSX. The V/I (Voltage/Current) control ramp circuit controls both the initial turn on voltage and the current limit of the output device. It works by monitoring the output voltage of the gate driver and adjusting the pulse width modulation (PWM) turn on and turn off times accordingly. The current limit is dynamically adjusted in response to output voltage, allowing for the most efficient device turn on. Power foldback is also employed to decrease the output voltage as the output current is increased, thus protecting the device against damage due to overloads or short circuits.

For stand-alone operation, the internal soft-start circuit consists of an autonomous ramp generator and a regulated drive. The regulated drive is able to turn on the high-side device immediately and regulate its turn-on voltage within a few microseconds. This ensures an efficient and safe device turn-on without external assistance. Additionally, since the FL3100TSX includes an overvoltage protection circuit, excessive drain to source voltages are automatically limited, providing a robust protection against power supply overvoltages.

Conclusion

The FL3100TSX offers a high-performance and low-power solution for high power applications that require fast switching times and high peak gate currents. It can be used with an optocoupler or directly connected to the output device and offers excellent power savings and fault tolerance. Its built-in V/I control circuit, soft-start ramp generator and overvoltage protection circuits provide a robust and efficient protection against overvoltages, short circuits and overloads.