The SI2302 (marked as A2SHB) is a high-density, sub-logic level N-Channel enhancement mode field-effect transistor utilizing advanced trench MOSFET technology. Engineered to provide low on-state resistance (R_DS(ON)), low gate charge, and fast switching performance within a miniature SOT-23 surface-mount footprint, it is an ideal solution for low-side load switching, power management, PWM control, and logic-level translation in battery-operated and space-constrained electronic circuits.

Specifications

• Brand / Manufacturer: Vishay Siliconix / Industry Standard
• Part Number / Marking: SI2302 / SI2302CDS / A2SHB
• Transistor Type: N-Channel MOSFET
• Drain-Source Breakdown Voltage (V_DS): 20V
• Gate-Source Voltage (V_GS): ±8V
• Continuous Drain Current (I_D): 2.8A (at V_GS = 4.5V, T_A = 25°C) / 2.3A (at V_GS = 2.5V)
• Pulsed Drain Current (I_DM): 10A
• Low On-Resistance (R_DS(ON)): < 57m>GS = 4.5V (I_D = 3.6A)
• Low On-Resistance (R_DS(ON)): < 75m>GS = 2.5V (I_D = 3.1A)
• Gate Threshold Voltage (V_GS(th)): 0.40V to 0.85V (Typical ~0.7V)
• Total Gate Charge (Q_g): Approx. 3.5nC (at V_GS = 4.5V)
• Maximum Power Dissipation (P_D): 0.86W to 1.25W (at T_A = 25°C)
• Operating Junction & Storage Temperature: -55°C to +150°C
• Package / Case: SOT-23 (TO-236) Surface Mount (Pin 1: Gate, Pin 2: Source, Pin 3: Drain)

Features

• Advanced TrenchFET Power Technology: Delivers high cell density and exceptionally low conduction losses (R_DS(ON)) to minimize thermal buildup during continuous current switching.
• Sub-Logic Level Gate Drive: Fully turns ON with low gate drive voltages down to 2.5V, allowing seamless direct drive from 3.3V and 5V microcontrollers (ESP32, STM32, Arduino) without auxiliary buffer stages.
• High Current Handling in Miniature Footprint: Safely handles continuous drain currents up to 2.8A within a standard compact SOT-23 package.
• Fast Switching Speed: Low input capacitance and a low gate charge of ~3.5nC ensure quick transitions with minimal switching losses during high-frequency PWM switching.
• High Reliability & ESD Robustness: Designed for stable gate breakdown resilience and efficient heat transfer through surface-mount PCB copper traces.

Common Applications

• Low-Side Load Switches: Power gating for sub-modules, wireless radios, sensors, and displays in battery-powered IoT devices.
• DC Motor & Solenoid Drivers: Low-side switching for small DC vibration motors, cooling fans, micro-pumps, and relay coils.
• LED Dimming & Driving: High-efficiency PWM brightness control for LED strips, backlights, and status indicators.
• Bidirectional Logic Level Shifting: Standard active component in bidirectional I2C, SPI, and UART level converter circuits between 1.8V, 3.3V, and 5V systems.
• DC-DC Buck & Boost Converters: Synchronous rectification and primary power switching in low-voltage step-down/step-up topologies.

Usage Tips

• Gate Current Limiting Resistor: Insert a small series resistor (10Ω to 100Ω) between the microcontroller GPIO pin and the Gate (Pin 1) to damp high-frequency oscillation ringing and protect the MCU output from inrush charging spikes.
• Gate Pull-Down Resistor: Always place a 10kΩ to 100kΩ pull-down resistor from Gate to Source (GND) to guarantee the MOSFET stays fully OFF during MCU bootup, reset, or floating pin states.
• Inductive Kickback Protection: When switching inductive loads (such as DC motors, buzzers, or relays), place a fast-recovery flyback diode (e.g., 1N5819 Schottky) across the load to protect the MOSFET against inductive voltage spikes exceeding the 20V V_DS rating.
• Gate Voltage Clamping: Ensure the Gate-to-Source differential voltage never exceeds the ±8V maximum rating; do not drive the gate directly with 12V or higher rails without a proper voltage divider.

Datasheet