FDG901D

Overview

The FDG901D is a slew rate control IC designed for P-Channel MOSFETs, manufactured by onsemi. It operates within a supply voltage range of 2.7V to 6V and features three programmable slew rates controlled via the SLEW pin: open (approx. 80µA gate current), ground (approx. 1µA), and VDD (approx. 10nA). The device utilizes a SC70-5 surface mount package and includes a logic input compatible with CMOS levels between 2.55V and 5V. During turn-on, it regulates the MOSFET gate drive to limit inrush current, while ensuring rapid turn-off.

Feature Summary

• Controls P-Channel MOSFET turn-on speed to limit inrush current in high capacitance load applications
• Provides three selectable slew rate settings via the SLEW pin to balance switching speed and EMI reduction
• Ensures fast turn-off performance by actively pulling the MOSFET gate up
• Operates with low-power CMOS logic inputs compatible with standard digital voltages

Applications

• Battery load switches in portable electronics
• Power management systems requiring controlled power-up sequences
• Circuits with high capacitive loads where inrush current suppression is critical

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm the specific revision level matches design requirements, as specifications may evolve. Ensure the SC70-5 footprint aligns with PCB layout constraints. Check for RoHS compliance documentation if environmental regulations apply to the final assembly.

Selection Notes

Select this component when precise control over P-Channel MOSFET switching speed is required to protect battery sources or reduce electromagnetic interference. Evaluate the load capacitance and desired rise time to determine the appropriate SLEW pin configuration. Ensure the system logic voltage falls within the specified input range for reliable operation without additional level shifting.

Part Context

This component belongs to the family of slew rate control drivers intended for interfacing low-voltage digital circuitry with power MOSFETs. It addresses common issues in battery-powered devices where sudden power application causes supply transients. The design focuses on minimizing PCB area compared to external RC networks while providing configurable performance.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Verify functional compatibility regarding gate drive current capabilities, operating voltage ranges, and package dimensions before considering alternative manufacturers.

FAQ

How does the FDG901D handle the turn-off phase of the MOSFET?

For turn-off, the IC pulls the MOSFET gate up quickly to ensure efficient switching, distinct from the controlled slew rate used during turn-on.

What determines the specific slew rate setting?

The slew rate is determined by the voltage applied to Pin 2 (SLEW): connecting it to VDD provides the lowest current (~10nA), Ground provides medium current (~1µA), and leaving it open provides the highest current (~80µA).

Is the logic input compatible with all microcontroller voltages?

The logic input is CMOS compatible with a minimum high input voltage of 2.55V at a 6V power rail, making it suitable for standard 3.3V and 5V logic systems.