UM6K33NTN vs SSM6N58NU,LF: Dual N-Channel MOSFET Array Comparison
Quick verdict
For low-current, low-voltage switching with minimal gate drive, the UM6K33NTN excels due to its 1.2 V logic-level gate drive and ultra-low input capacitance, making it ideal for signal-level loads and battery-powered applications. Conversely, the SSM6N58NU,LF is a clear choice for higher current loads (up to 4 A) and power switching up to 30 V, offering significantly lower R_DS(on) and higher power dissipation capability for demanding power stages.
Spec comparison table
| Spec | UM6K33NTN | SSM6N58NU,LF | Notes |
|---|---|---|---|
| Configuration | 2 N-Channel (Dual) | 2 N-Channel (Dual) | Equivalent |
| Continuous Drain Current @ 25°C | 200 mA | 4 A | SSM6N58NU,LF supports 20x higher current — critical for power switching |
| Drain-Source Voltage Max (V_DS) | 50 V | 30 V | UM6K33NTN offers higher voltage margin for 30–50 V rails |
| Power Dissipation Max | 120 mW | 1 W | SSM6N58NU,LF can handle ~8x more power dissipation — better for higher thermal loads |
| Gate Drive Voltage (Logic Level) | 1.2 V | 1.8 V | UM6K33NTN has lower gate drive threshold, easier to switch at very low voltages |
| Gate Threshold Voltage (V_GS_th) | 1 V @ 1 mA | 1 V @ 1 mA | Equivalent |
| R_DS(on) Max @ I_D, V_GS | 2.2 Ω @ 200 mA, 4.5 V | 84 mΩ @ 2 A, 4.5 V | SSM6N58NU,LF delivers drastically lower conduction losses at realistic currents |
| Input Capacitance (C_iss) | 25 pF @ 10 V | 129 pF @ 15 V | UM6K33NTN’s lower input capacitance reduces gate drive losses and switching power |
| Gate Charge (Q_g) | Not specified | 1.8 nC @ 4.5 V | SSM6N58NU,LF has known gate charge; UM6K33NTN data unavailable — expect lower with smaller device |
| Package | 6-TSSOP (UMT6) | 6-WDFN (2x2) Exposed Pad | SSM6N58NU,LF’s exposed pad package improves thermal dissipation |
| Mounting Type | Surface Mount | Surface Mount | Equivalent |
| Operating Temperature Range | Up to 150 °C (TJ) | Up to 150 °C (TJ) | Equivalent |
| Technology | MOSFET (Metal Oxide) | MOSFET (Metal Oxide) | Equivalent |
Design trade-offs
The most significant difference between the UM6K33NTN and the SSM6N58NU,LF is their target application current and power range. The UM6K33NTN is optimized for low-current switching and logic-level control with a very low gate drive voltage threshold (1.2 V logic level). Its extremely low input capacitance (25 pF) and relatively high R_DS(on) (2.2 Ω at 200 mA) make it suitable for switching small loads or multiplexing signals with minimal gate drive losses and simple driver circuits.
In contrast, the SSM6N58NU,LF targets moderate power loads, with a continuous drain current rating of 4 A and a much lower R_DS(on) of 84 mΩ at 2 A and 4.5 V gate drive. This translates to significantly lower conduction losses in power switching applications. The gate charge of 1.8 nC at 4.5 V is moderate for a power MOSFET in this class, but the larger input capacitance (129 pF) means gate drive losses and switching times will be higher compared to the UM6K33NTN. This makes the SSM6N58NU,LF more suited for applications where power efficiency and thermal management are critical, and a stronger gate driver is available.
Thermally, the SSM6N58NU,LF’s 6-WDFN exposed pad package enables better heat dissipation, allowing it to sustain its 1 W power rating more reliably. The UM6K33NTN’s 6-TSSOP (UMT6) package is smaller and simpler but limited to 120 mW, restricting its use to low-power scenarios or where thermal dissipation is less critical.
From a layout perspective, the SSM6N58NU,LF requires careful attention to the exposed pad soldering and thermal vias to maximize heat sinking. The UM6K33NTN’s smaller package and lower power dissipation simplify PCB thermal design but restrict current capacity and make it unsuitable for high-load applications.
Cost-wise, the UM6K33NTN, given its lower current rating and simpler package, will generally be less expensive in volume and easier to source for low-power designs. The SSM6N58NU,LF’s power capability and package complexity likely come at a higher unit cost but are justified in power-critical designs.
Use-case fit
Choose UM6K33NTN when:
- Switching or multiplexing low-current signals below 200 mA at voltages up to 50 V.
- Driving loads from low-voltage logic rails (down to 1.2 V gate drive) without additional level shifting.
- Battery-powered or energy-sensitive devices requiring minimal gate drive losses and low quiescent current.
- Compact, low-power sensor interface switches or signal routing where power dissipation must be minimal.
- Applications with limited PCB area and no significant heat sinking capabilities.
Choose SSM6N58NU,LF when:
- Switching DC loads up to 4 A at voltages up to 30 V, such as motor drivers, LED drivers, or power rails.
- Efficiency and conduction loss reduction are critical, especially at currents above 1 A.
- Implementing power switches with 1 W or higher dissipation allowance and requiring robust thermal management.
- Gate drivers can supply 1.8 V or higher drive voltage, and switching speed is important but secondary to conduction loss.
- Designs where exposed pad thermal dissipation can be fully exploited for improved reliability.
Drop-in compatibility
There is no indication that these two parts are pin- or footprint-compatible. The UM6K33NTN uses a 6-TSSOP (UMT6) package, while the SSM6N58NU,LF is in a 6-WDFN (2x2 mm) exposed pad package. The pinouts and package dimensions differ, making them non-interchangeable without PCB redesign. Substituting one for the other requires reworking the PCB footprint and thermal layout; the exposed pad on the SSM6N58NU,LF especially demands a dedicated thermal land and vias.
Alternatives to consider
- BSS138 (NXP): Single N-channel MOSFET with low gate charge, widely used in low-current switching applications.
- Si2302 (Vishay): Low-voltage MOSFET optimized for load switching up to a few amps, with low R_DS(on) in a small SOT-23 package.
- IRLML2502 (Infineon): Logic-level MOSFET with R_DS(on) around 100 mΩ at 4.5 V, suitable for moderate current loads and low gate drive voltages.