MMBF5485 vs SQ1922AEEH-T1_GE3: Component Comparison for Power Electronics Design

Quick verdict

For low-current, high-frequency RF switching or amplification up to 400 MHz, the MMBF5485 JFET offers a simpler, lower-noise solution with a 25 V rating and low current requirements. For power switching or load-driving applications requiring up to 0.85 A continuous current at 20 V, the dual N-channel MOSFET array SQ1922AEEH-T1_GE3 delivers significantly higher current capability and integrated dual devices in a compact SC-70-6 package.

Spec comparison table

SpecMMBF5485SQ1922AEEH-T1_GE3Notes
ConfigurationN-Channel JFET2 × N-Channel MOSFETSQ1922AEEH offers dual devices in one package, enabling half-bridge or dual-switch designs.
Current rating (continuous)10 mA850 mA (Tc), 1 A (min), 1.2 A (typ)SQ1922AEEH supports ~85× higher continuous current, critical for power applications.
Frequency400 MHzNot specified (switching freq typical 10 ms)MMBF5485 targets RF applications; SQ1922AEEH is low-frequency switching/power MOSFET.
Voltage rating (max)25 V20 VMMBF5485 has slightly higher voltage rating, useful in some RF or low-power circuits.
GainNot specifiedNot specifiedGain not specified for either; MMBF5485 JFET likely has gain for RF; MOSFET used as switch.
Noise figure4 dBNot specifiedMMBF5485 offers low noise figure, important for RF front-ends.
Mounting typeSurface Mount (SOT-23-3)Surface Mount (SC-70-6)Both surface mount; SQ1922AEEH uses smaller 6-pin SC-70-6 package vs 3-pin SOT-23-3.
Package caseTO-236-3, SC-59, SOT-23-3SC-70-6 (6-pin MOSFET array)SQ1922AEEH’s smaller package supports dual devices, saving PCB area.
TechnologyJFETMOSFET (Metal Oxide)Different transistor types; JFET better for RF linearity/noise, MOSFET better for power switching.
Voltage test (max)15 V20 VSQ1922AEEH rated for higher test voltage, aligns with max voltage rating.
Continuous drain current min10 mA0.85 A (Tc), 1 A (min)SQ1922AEEH supports significantly higher load current.
Continuous drain current typNot specified0.53 ATypical current lower than min rating; design for min rating for reliability.
Drain-source on-state resistance (Rds(on))Not specified0.490 Ω (typ), 0.530 Ω (max) @ 4.5 V, 400 mASQ1922AEEH has defined Rds(on); low but not ultra-low, appropriate for low-power switching.
Gate charge (Qg) maxNot specified1.2 nC @ 4.5 VSQ1922AEEH requires moderate gate charge drive, manageable with low gate drive currents.
Gate-source threshold voltage (Vth)Not specified1.5 V (min), 2 V (typ), 2.5 V (max)SQ1922AEEH’s threshold voltage suitable for low-voltage logic-level operation.
Maximum junction temperature (Tj)Not specified175 °CSQ1922AEEH rated for automotive high-temp operation.
Operating temperature rangeNot specified-55 °C to 175 °C (TJ)SQ1922AEEH supports wide automotive temperature range.
Power dissipation maxNot specified0.2 W (max), 0.5 W (typ)SQ1922AEEH power dissipation limited, requires thermal management for high current.
Pulsed drain current maxNot specified3.3 ASQ1922AEEH supports short pulses up to 3.3 A, useful for switching transients.
Package dimensions (L × W)SOT-23-3 (typ ~2.9 × 1.3 mm)0.5 × 0.6 in (12.7 × 15.24 mm)SQ1922AEEH package larger due to dual MOSFETs but still compact.
Gate resistance (Rg) typicalNot specified8.5 ΩSQ1922AEEH moderate gate resistance affects switching speed and drive requirements.
Noise figure4 dBNot specifiedMMBF5485 better for low-noise RF front ends.
Rise time / fall time typicalNot specified15 ns (rise), 10 ns (fall)SQ1922AEEH switching speed suitable for low-frequency power switching.
Body diode forward voltage (max)Not specifiedLimited by R a (max)SQ1922AEEH has body diode; voltage drop depends on package thermal resistance.
TechnologyJFETMOSFETJFET better for linear low-noise RF; MOSFET better for power switching and load handling.
Supplier device packageSOT-23-3SC-70-6Different footprint and pin count.
QualificationNot specifiedAEC-Q101 (Automotive Grade)SQ1922AEEH qualified for automotive applications, indicating higher reliability standards.

Design trade-offs

The MMBF5485 and SQ1922AEEH-T1_GE3 serve fundamentally different application niches despite both being N-channel devices in surface-mount packages. The MMBF5485 is a JFET designed for RF front-end use, supporting operation up to 400 MHz with a noise figure of 4 dB, which is critical in low-noise amplifier or RF switching applications. Its voltage rating is higher (25 V max) and it operates at very low continuous current (10 mA max), meaning it is not intended for power switching but rather signal-level amplification or switching. The JFET technology enables low input capacitance and good linearity but requires careful biasing and is less tolerant of voltage spikes.

In contrast, the SQ1922AEEH-T1_GE3 is a dual MOSFET array optimized for power switching and load control at voltages up to 20 V and continuous drain currents up to 850 mA (Tc). It is built in a 6-pin SC-70 package containing two N-channel MOSFETs, simplifying half-bridge or dual-switch designs in compact spaces. The MOSFET’s Rds(on) of ~0.5 Ω at moderate gate drive voltages (4.5 V) results in conduction losses that must be considered in thermal design, especially since the power dissipation max is 0.5 W typical. Gate charge is moderate (1.2 nC @ 4.5 V), requiring gate drivers capable of sourcing tens of milliamps for fast switching, but this is manageable in typical low-voltage control circuits.

Thermally, the SQ1922AEEH-T1_GE3 has well-documented thermal resistances and is qualified for automotive-grade temperature ranges (-55 °C to 175 °C), which is an advantage for robust industrial or automotive use. The MMBF5485 datasheet does not specify thermal limits or ruggedness, reflecting its intended use in controlled low-power RF circuits. From a layout perspective, the SQ1922AEEH’s dual MOSFETs in a single package reduce PCB area and routing complexity for dual-switch topologies, but its SC-70-6 footprint is not compatible with the MMBF5485’s 3-pin SOT-23-3, requiring different PCB layouts.

Cost-wise, the MMBF5485 is likely less expensive due to simpler device structure and packaging, but this is offset by its limited current capability and niche use. The SQ1922AEEH-T1_GE3, with automotive qualification and dual MOSFETs, is more complex and typically higher cost but adds design flexibility and robustness.

Use-case fit

Choose MMBF5485 when…