onsemi TIP48

Overview

TIP48 from ON Semiconductor is a high-voltage NPN silicon power transistor in TO-220 package, rated for 300 V collector-emitter sustaining voltage (V_CEO(sus)), 1 A DC collector current, and 40 W case power dissipation at 25°C - used in line-voltage switching, relay drivers, and horizontal deflection circuits in CRT-based displays.

For engineers reviewing the TIP48 datasheet, pinout, applications, or equivalent options, key selection criteria include its 300 V V_CEO(sus), 1 A I_C, TO-220 thermal performance, and verified suitability for high-sustaining-voltage linear and switching operation in industrial power control.

Technical Context

The TIP48 operates as a general-purpose NPN bipolar junction transistor with fixed gain structure optimized for medium-power switching and linear amplification. Its design supports safe operation up to 300 V V_CEO(sus) under pulsed conditions and maintains stable h_FE between 10–150 across 0.3–1 A collector current range.

Thermal management relies on case-mounted heatsinking due to its 40 W P_C rating at T_C = 25°C and 2 W P_D at ambient temperature. The device exhibits V_CE(sat) ≤ 1 V at I_C = 1 A / I_B = 0.2 A and f_T = 10 MHz, confirming usable bandwidth for audio-frequency and low-MHz switching applications.

Key Specifications

Pinout & Package

Package: TO-220 3L (Single Gauge), through-hole, case-isolated, with metal tab electrically connected to collector.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN high-voltage switching transistor applications.

Compared with MJE13003 and 2N3055, the TIP48 uniquely balances 300 V blocking, 1 A DC current, and TO-220 thermal scalability - making it optimal for cost-sensitive, medium-power industrial switching where voltage margin exceeds 240 VAC peak but full TO-3 packaging is unnecessary.

Availability

TIP48 is available at Aetrix Electronics and suitable for industrial relay drivers, CRT deflection circuits, and offline SMPS auxiliary switches requiring stable component supply and long-term manufacturability.

Supply support for TIP48 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

ON Semiconductor is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, and consumer markets.

The TIP48 belongs to ON Semiconductor's legacy high-voltage bipolar transistor portfolio - originally developed by Fairchild - designed specifically for robust, cost-effective switching in mains-powered industrial and display equipment.

FAQ

What is the maximum collector-emitter sustaining voltage of the TIP48?

The TIP48 has a guaranteed collector-emitter sustaining voltage (V_CEO(sus)) of 300 V under specified test conditions (I_C = 30 mA, I_B = 0). This rating reflects its ability to block transient overvoltages in switching applications such as flyback converters and relay drivers without breakdown. The TIP48 datasheet confirms this value is measured per JEDEC standards and applies directly to the TIP48 part number.

Is the TIP48 pin-compatible with other devices in the TIP47–TIP50 family?

Yes, the TIP48 shares identical TO-220 3L pinout (Base–Collector–Emitter) and mechanical footprint with TIP47, TIP49, and TIP50. All devices in this family use the same lead assignment: Pin 1 = Base, Pin 2 = Collector (tab), Pin 3 = Emitter. However, electrical ratings differ - for example, TIP48 offers 300 V V_CEO(sus), while TIP47 is rated at 250 V. The TIP48 remains interchangeable at the board level within this family when voltage requirements align.

What is the typical DC current gain (h_FE) of the TIP48 at 1 A collector current?

At V_CE = 10 V and I_C = 1 A, the TIP48 exhibits a minimum h_FE of 10 and a maximum of 150, with typical values falling within that range. This gain specification is confirmed in the official ON Semiconductor datasheet for TIP48 and defines base drive requirements for reliable saturation. Designers must size base resistors assuming h_FE ≥ 10 to ensure full turn-on across process and temperature variations in the TIP48.

Can the TIP48 be used in linear amplifier applications?

Yes, the TIP48 supports linear operation with verified SOA curves up to 1 ms pulse width and defined thermal limits. Its V_CE(sat) ≤ 1 V and h_FE stability make it suitable for Class-A/B audio output stages and precision current sources where moderate voltage swing (<300 V) and ≤1 A current are required. However, linear use demands careful heatsinking - the TIP48's 40 W P_C rating assumes proper case temperature control, and continuous operation above 1 W requires thermal analysis per the TIP48 SOA graph.

Does the TIP48 have an insulated package or require electrical isolation from the heatsink?

The TIP48 uses a non-insulated TO-220 package where the metal tab is internally connected to the collector terminal. Therefore, electrical isolation from the heatsink is mandatory unless the collector node is intentionally grounded or referenced to the heatsink potential. Standard practice is to use a mica or silicone insulator washer with thermal grease, verified for ≥500 V dielectric strength, to prevent short-circuit failure. This requirement applies specifically to the TIP48 and is documented in its physical dimensions and mounting guidelines.