UM6K33NTN vs AO6604 MOSFET Arrays: A Detailed Component Comparison
Quick verdict
For low-current, low-voltage switching with minimal gate drive, the UM6K33NTN is a better fit due to its 1.2V logic-level gate drive and ultra-low current rating (200mA), simplifying gate drive and reducing power dissipation. Conversely, for higher current loads up to 3.4A and complementary N/P channel configurations in 20V systems, the AO6604 delivers dramatically lower R_DS(on) and higher power dissipation capability, making it the preferred choice for moderate power DC-DC conversion or load switching.
Spec comparison table
| Spec | UM6K33NTN | AO6604 | Notes |
|---|---|---|---|
| Configuration | 2 x N-Channel | N-Channel + P-Channel | AO6604 offers complementary pair enabling half-bridge or push-pull topologies. |
| Drain-Source Voltage, V_DS(max) | 50 V | 20 V | UM6K33NTN supports higher voltage; better for 24V+ systems. |
| Continuous Drain Current, I_D(25°C) | 200 mA | 3.4 A (N), 2.5 A (P) | AO6604 supports >10x higher current; UM6K33NTN limited to signal-level loads. |
| Power Dissipation, P_D(max) | 120 mW | 1.1 W | AO6604 can handle nearly 10x more power; critical for thermal design in higher loads. |
| R_DS(on) @ I_D, V_GS | 2.2 Ω @ 200 mA, 4.5 V | 65 mΩ @ 3.4 A, 4.5 V | AO6604’s R_DS(on) is orders of magnitude lower, reducing conduction losses significantly. |
| Gate Threshold Voltage, V_GS(th) | 1 V @ 1mA | 1 V @ 250µA | Both have similar threshold voltage, but AO6604’s threshold measured at lower current. |
| Gate Drive Voltage | 1.2 V Logic Level | 4.5 V Logic Level | UM6K33NTN supports ultra-low gate drive voltage; AO6604 requires standard 4.5V logic. |
| Gate Charge, Q_g | Not specified | 3.8 nC @ 4.5 V | AO6604’s gate charge moderate; UM6K33NTN’s unknown but expected lower due to smaller device size. |
| Input Capacitance, C_iss | 25 pF @ 10 V | 320 pF @ 10 V | UM6K33NTN input capacitance is 13x smaller, easing gate drive and switching losses. |
| Package | 6-TSSOP (UMT6) | 6-TSOP (SOT-457) | Packages differ; footprint compatibility unlikely without adaptation. |
| Mounting Type | Surface Mount | Surface Mount | Both are surface mount; similar PCB assembly processes. |
| Operating Temperature Range | up to 150°C (TJ) | -55°C to 150°C (TJ) | AO6604 rated for extended temp range; UM6K33NTN datasheet does not specify low temp. |
| Technology | MOSFET (Metal Oxide) | MOSFET (Metal Oxide) | Similar underlying technology. |
Design trade-offs
The UM6K33NTN targets low-current, low-voltage switching applications. Its 50V rating provides headroom for 12–24V rails, and the dual N-channel configuration is suited for simple switching or level shifting. The high R_DS(on) of 2.2 Ω at 200 mA means conduction losses dominate at higher currents, making it unsuitable for significant load currents or power switching. However, the very low input capacitance (25 pF) and ultra-low gate drive voltage (1.2 V typical) reduce switching losses and simplify gate driver requirements, allowing direct drive from low-voltage logic or microcontrollers without additional gate driver ICs.
In contrast, the AO6604 is designed for medium-power synchronous switching applications, such as DC-DC converters or load switches operating at up to 20V rails. The complementary N/P pair facilitates half-bridge or push-pull configurations, simplifying driver topology. The low R_DS(on) of 65 mΩ at 3.4 A drastically reduces conduction losses compared to UM6K33NTN, enabling higher efficiency and thermal headroom. Its gate charge of 3.8 nC at 4.5 V is moderate and requires a dedicated gate driver or at least a 4.5 V logic supply, increasing design complexity and power budget compared to UM6K33NTN.
Thermally, the AO6604’s 1.1 W dissipation rating allows operation in higher power scenarios, but board layout must ensure adequate heat sinking. The UM6K33NTN’s 120 mW limitation restricts it to signal-level loads or low duty cycle switching. In terms of package and footprint, the UM6K33NTN’s UMT6 package and the AO6604’s 6-TSOP (SOT-457) differ, preventing direct drop-in replacement without PCB changes.
From a cost perspective (not provided explicitly), the UM6K33NTN’s simpler device structure and lower current rating suggest it will be less expensive in volume. However, in applications where the AO6604’s higher current and complementary topology reduce system complexity and external components, the total solution cost may be lower despite a higher part cost.
Use-case fit
Choose UM6K33NTN when…
- Switching or level shifting low-voltage signals up to 50 V with very low current (<200 mA).
- Driving MOSFET gates or loads directly from 1.2 V logic or microcontrollers without dedicated gate drivers.
- Minimizing PCB area and gate drive complexity for low-power sensor or interface circuits.
- Operating in applications with tight gate charge or input capacitance constraints, such as high-speed logic-level switching.
- Thermal dissipation is limited to under 120 mW, such as in compact or thermally constrained embedded designs.
Choose AO6604 when…
- Designing synchronous rectification or half-bridge drivers in 12–20 V DC-DC converters requiring complementary MOSFET pairs.
- Switching moderate currents up to several amperes (3.4 A N-channel, 2.5 A P-channel) with low conduction losses.
- Operating with 4.5 V gate drive voltage available, enabling full enhancement of MOSFETs for efficiency.
- Thermal management allows up to 1.1 W dissipation, typically with proper PCB copper area or heat sinking.
- Implementing load switches or power multiplexing in systems requiring P-channel high-side switching and N-channel low-side switching in a single package.
Drop-in compatibility
The UM6K33NTN and AO6604 are not pin-compatible nor footprint-compatible. The UM6K33NTN comes in a 6-TSSOP (UMT6) package, while the AO6604 is housed in a 6-TSOP (SOT-457) package with complementary pinouts to support N and P channels. Substituting one for the other will require PCB redesign and firmware changes to handle different gate drive voltages and device polarities. The AO6604’s complementary pair cannot be emulated with the UM6K33NTN’s dual N-channel MOSFETs without additional components.
Alternatives to consider
- BSS138 (N-Channel, 50 V, ~200 mA): A common logic-level MOSFET for low-current switching, potentially lower cost and widely available.
- IRLML6344 (N-Channel, 30 V, 5.7 A, logic level): Higher current than UM6K33NTN with logic-level gate drive, useful for mid-power applications.
- Si2302DS (N-Channel, 20 V, 2.3 A): Comparable to AO6604 but single N-channel device, useful where complementary pairs are not required.