P-channel load switch in a 3-pin PICOSTAR
The Texas Instruments CSD25483F4 is a P-channel NexFET MOSFET rated for 20 V drain-source and 1.6 A continuous drain current, housed in a 3-PICOSTAR (3-XFDFN) package.
On-resistance and gate drive — what the numbers mean
Rds(on) is specified at 205 mOhm maximum with 500 mA drain current and 8 V gate drive. Gate charge is 0.959 nC at 4.5 V, and input capacitance is 198 pF at 10 V drain-source. These low values make the CSD25483F4 suitable for switching frequencies up to several hundred kHz without significant drive losses.
Temperature grade and deployment context
Rated for junction temperatures from -55 to 150 °C, this MOSFET fits automotive under-hood, industrial motor-drive, and outdoor telecom environments where ambient temperatures exceed 85 °C. The 500 mW power dissipation at 25 °C ambient (Ta) sets the thermal budget; in a 125 °C ambient the allowable dissipation derates to roughly 200 mW, so the actual continuous current must be reduced accordingly.
Package and footprint — the 3-PICOSTAR
The 3-XFDFN (3-PICOSTAR) is a 1.0 mm × 0.6 mm body with 0.35 mm pitch — one of the smallest discrete MOSFET packages available. The centre pad is the drain; the two outer pads are gate and source. The small footprint suits space-constrained designs like wearables, smartphone sub-circuits, and compact IoT modules, but the 0.35 mm pitch requires careful solder-paste stencil design and a controlled reflow profile.
Lifecycle and compliance
It is ROHS3 compliant and Pb-free, meeting the Restriction of Hazardous Substances directive for lead, mercury, cadmium, and other controlled substances.