Toshiba Semiconductor and Storage SSM3K329R,LF

Overview

SSM3K329R from Toshiba Electronic Devices & Storage Corporation is a silicon N-channel MOSFET designed for low-voltage, high-speed power switching applications. It supports 1.8 V gate drive, delivers R_DS(ON) = 289 mΩ (max) at V_GS = 1.8 V, and operates with V_DSS = 30 V and I_D = 3.5 A (DC), commonly used in compact DC-DC converter load switches and battery-powered logic-level switching circuits.

For engineers reviewing the SSM3K329R datasheet, SSM3K329R pinout, SSM3K329R application, or SSM3K329R equivalent, key selection criteria include verified 1.8 V logic compatibility, SOT-23F package thermal performance on FR4, R_DS(ON) vs. V_GS curve behavior, and safe operating area under pulsed drain current conditions.

Technical Context

This discrete MOSFET employs planar silicon process technology optimized for low-threshold switching in space-constrained portable electronics. Its gate threshold voltage (V_th = 0.4–1.0 V) enables reliable turn-on with 1.8 V microcontroller I/O, while its dynamic characteristics-C_iss = 123 pF (typ), t_on = 9.2 ns (typ)-support clean edge transitions in high-frequency PWM control.

The device features an integrated body diode with V_DSF = −0.9 to −1.2 V at I_D = −3.5 A, enabling bidirectional current handling in synchronous rectifier or reverse-polarity protection configurations. Thermal design must account for R_th(ch-a) dependence on PCB copper area per Toshiba's FR4 reference layout (645 mm² pad).

Key Specifications

Pinout & Package

SOT-23F surface-mount package: ultra-compact 2.9 × 1.3 × 1.0 mm footprint with gull-wing leads, optimized for automated assembly and thermal dissipation via exposed drain pad (pin 3) on PCB copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel MOSFET switching applications.

Compared with DMN10H750S and AO3400, the SSM3K329R uniquely supports guaranteed turn-on at 1.8 V with sub-300 mΩ R_DS(ON), making it optimal for energy-sensitive, low-voltage embedded systems where gate drive voltage is fixed and minimal conduction loss is critical.

Availability

SSM3K329R is available at Aetrix Electronics and suitable for battery management systems, USB power delivery controllers, and portable DC-DC converter designs requiring stable component supply across long production cycles.

Supply support for SSM3K329R includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Toshiba Electronic Devices & Storage Corporation designs and manufactures discrete semiconductors, power devices, and logic ICs with emphasis on reliability, miniaturization, and energy efficiency.

The SSM3K329R belongs to Toshiba's SSM series of small-signal MOSFETs engineered specifically for low-voltage, high-speed switching in space-constrained portable electronics and power management ICs.

FAQ

What is the minimum gate voltage required to fully turn on the SSM3K329R?

The SSM3K329R has a gate threshold voltage (V_th) range of 0.4–1.0 V, but full enhancement requires V_GS ≥ 1.8 V to achieve R_DS(ON) ≤ 289 mΩ (max). At 1.8 V, it delivers guaranteed low on-resistance suitable for logic-level switching; operation below 1.8 V results in significantly higher R_DS(ON) and unpredictable conduction. The SSM3K329R is explicitly characterized and rated for 1.8 V drive in Toshiba's datasheet Rev.1.0.

Is the SSM3K329R suitable for high-frequency PWM applications?

Yes, the SSM3K329R supports high-frequency PWM use with t_on = 9.2 ns and t_off = 6.4 ns (typical) at V_GS = 2.5 V, and C_iss = 123 pF (typ). These values enable clean switching above 1 MHz in properly laid-out layouts. However, gate drive strength and PCB parasitics must be optimized-the SSM3K329R's low Q_g (1.5 nC typ) minimizes driver loading, making it well-suited for MCU-driven PWM in compact DC-DC converters.

Can the SSM3K329R be used in a high-side switch configuration?

The SSM3K329R is an N-channel MOSFET and is not self-sufficient for high-side switching without external gate boosting. In high-side applications, it requires a gate driver capable of supplying V_GS ≥ 1.8 V referenced to the drain potential. While feasible with charge-pump or bootstrap drivers, its SOT-23F package and 30 V V_DSS rating make it more commonly deployed as a low-side switch. For dedicated high-side use, a P-channel alternative or integrated high-side switch is typically preferred.

What thermal considerations apply to the SSM3K329R in continuous operation?

The SSM3K329R's maximum channel temperature is 150 °C, and its power dissipation (P_D) is rated at 1 W on a standard FR4 board (25.4 × 25.4 × 1.6 mm, 645 mm² Cu pad). To sustain 3.5 A DC current, PCB copper area and airflow must be validated per Toshiba's thermal curves (Fig. 7.13). Derating is required above 25 °C ambient; at 70 °C, P_D drops to ~0.6 W. The SSM3K329R's drain-connected die pad is the primary thermal path-ensure adequate solder mask opening and thermal vias beneath pin 3.

Does the SSM3K329R include integrated ESD protection?

No, the SSM3K329R does not integrate ESD protection circuitry. Toshiba explicitly warns that the device is sensitive to electrostatic discharge, with gate leakage limited to ±1 µA at ±12 V. Handling requires strict adherence to JESD22-A114 standards: grounded workstations, ionized air, ESD-safe soldering irons, and conductive packaging. Board-level TVS or RC filters may be added near the gate if system-level ESD stress is expected, but the SSM3K329R itself relies entirely on external precautions.