BSS84LT1G

The BSS84LT1G from onsemi is a P-channel enhancement-mode small signal MOSFET manufactured using proprietary high cell density DMOS technology. This process minimizes on-state resistance while providing rugged and reliable performance with fast switching characteristics. The device is rated for -50 V drain-source voltage and -130 mA continuous drain current, with RDS(on) of 10 Ω maximum at VGS = -5 V. It can deliver pulsed currents up to -520 mA, making it suitable for switching applications requiring brief high-current bursts. The SOT-23 package offers a compact footprint ideal for high-density PCB layouts in portable and battery-powered equipment.

The BSS84LT1G operates as a voltage-controlled P-channel switch. When the gate-to-source voltage (VGS) exceeds the threshold voltage (approximately -0.9 V to -2.0 V), an inversion channel forms between the P+ source and P+ drain regions through the N-type body, allowing current to flow from source to drain. The RDS(on) decreases with increasing |VGS|, reaching a typical value of 5 Ω at VGS = -10 V. The DMOS cell structure provides a high channel density that minimizes on-resistance per unit area. The enhancement-mode operation ensures the device is normally off (no conduction at VGS = 0), providing a safe default state for power control applications. The low gate charge of 2.2 nC enables fast switching transitions with minimal drive current requirements.

• High-side load switching: Controlling power to sensors, LEDs, or peripherals from MCU GPIO pins in battery-powered devices
• Level shifting: Translating logic signals between different voltage domains using P-channel pull-up configuration
• Power gating: Disconnecting subsystems in ultra-low-power designs to minimize standby current
• Battery protection: Simple overcurrent or reverse-polarity detection in portable electronics
• Audio muting: Fast analog signal switching in headphone/speaker mute circuits