BD235 Datasheet | Next Electromics

BD235 NPN Power Transistor Technical Summary

Overview

The BD235 is a silicon epitaxial-base NPN power transistor designed for general-purpose amplifier and switching applications. Manufactured in Jedec SOT-32 plastic packaging, it offers robust performance in medium-power circuits. Along with its complementary PNP counterpart (BD237), the BD235 provides designers with a reliable solution for push-pull configurations and other symmetrical circuit topologies.

This device features a low saturation voltage and high current gain, making it suitable for applications requiring efficient power handling. The transistor's construction ensures good thermal stability and is optimized for operation in environments where moderate power dissipation is required.

Key Features

High Current Capability: Collector current (Ic) up to 2A for robust power handling.
Low Saturation Voltage: V_CE(sat) typically 0.5V at I_C = 1.5A, improving efficiency in switching applications.
Complementary Pair Available: BD237 PNP version for symmetrical circuit designs.
Good Linearity: Suitable for audio amplification and signal processing.
High Gain Bandwidth Product: Transition frequency (f_T) of 3MHz ensures stable operation in amplification circuits.
Thermal Stability: Designed to operate within a junction temperature range of -65°C to +150°C.

Applications

The BD235 finds use in a wide range of electronic circuits, including:

Audio Amplifiers: Output stages in Class AB amplifiers due to its linear characteristics.
Power Switching: Driver stages in relay and motor control circuits.
Voltage Regulation: Series pass elements in linear power supplies.
General Purpose Amplification: Signal amplification in various analog circuits.
Push-Pull Configurations: Paired with BD237 for symmetrical output stages.

Electrical Characteristics

Absolute Maximum Ratings

Collector-Emitter Voltage (V_CEO): 45V
Collector-Base Voltage (V_CBO): 60V
Emitter-Base Voltage (V_EBO): 5V
Collector Current (I_C): 2A (continuous)
Total Power Dissipation (P_tot): 25W at T_case ≤ 25°C
Junction Temperature (T_j): -65°C to +150°C

Thermal Characteristics

Thermal Resistance, Junction-to-Case (R_thJC): 10°C/W
Thermal Resistance, Junction-to-Ambient (R_thJA): 70°C/W

Typical Performance Characteristics

DC Current Gain (h_FE): 40-250 at I_C = 0.5A, V_CE = 2V
Collector-Emitter Saturation Voltage (V_CE(sat)): 0.5V max at I_C = 1.5A, I_B = 0.15A
Transition Frequency (f_T): 3MHz typical at I_C = 0.1A, V_CE = 5V
Output Capacitance (C_obo): 100pF typical at V_CB = 10V, f = 1MHz

Package Information

SOT-32 Mechanical Data

Package Type: Jedec SOT-32 (TO-126 compatible)
Weight: Approximately 1.1 grams
Termination: Lead (Pb)-free, RoHS compliant
Mounting: Through-hole, with recommended pad layout per Jedec standards

Package Dimensions (mm)

Total Height: 9.5 max
Lead Length: 10.0 nominal
Lead Diameter: 0.6 ±0.05
Body Width: 6.6 ±0.3
Lead Spacing: 5.45 ±0.2

Reliability and Qualification

The BD235 meets or exceeds the following reliability standards:

JEDEC JESD22-A104 (Temperature Cycling)
JESD22-A101 (Steady-State Temperature Humidity Bias Life Test)
JESD22-B105 (Lead Integrity)

All devices are 100% tested for key parameters including breakdown voltages, leakage currents, and current gain to ensure consistent performance across production lots.