onsemi MPS3703

Overview

MPS3703 from Fairchild Semiconductor is a PNP general-purpose bipolar junction transistor designed for amplification and switching applications up to 500 mA collector current, with V_CEO = 30 V, h_FE = 30–150 at I_C = 50 mA, and f_T = 100 MHz - used in low-voltage DC-DC converter bias circuits, discrete audio preamplifiers, and relay drivers.

For engineers reviewing the MPS3703 datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package, PNP polarity, guaranteed V_(BR)CEO ≥ 30 V, continuous I_C rating of 800 mA, and thermal resistance R_θJA = 200 °C/W under standard mounting conditions.

Technical Context

The MPS3703 operates as a silicon PNP BJT fabricated on Fairchild's Process 63, optimized for linear amplification and saturated switching. Its DC current gain (h_FE) spans 30–150 at V_CE = 5.0 V and I_C = 50 mA, while V_CE(sat) remains ≤ 0.25 V under I_C = 50 mA / I_B = 5.0 mA drive - enabling efficient low-side switch operation.

Small-signal performance includes f_T = 100 MHz at I_C = 50 mA and V_CE = 5.0 V, with Cob = 12 pF at V_CB = 10 V, supporting audio-frequency and low-speed digital signal conditioning. Junction temperature range extends from –55 °C to +150 °C, validated per absolute maximum ratings.

Key Specifications

Pinout & Package

Package: TO-92 - 3-lead through-hole plastic package with standardized lead spacing (0.500″ pitch), flat side marking orientation, and 0.1977 g unit weight. Compatible with wave soldering and manual prototyping.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP general-purpose amplifier applications.

Compared with PN2907A and BC557, the MPS3703 offers balanced trade-offs: moderate V_CEO (30 V), verified Process 63 reliability, and documented f_T = 100 MHz - making it optimal for cost-sensitive industrial controls where 30–50 V operation and predictable gain at 50 mA are primary requirements.

Availability

MPS3703 is available at Aetrix Electronics and suitable for relay driver circuits, discrete audio preamplifiers, and DC-DC converter bias networks requiring stable component supply and long-term obsolescence management.

Supply support for MPS3703 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The MPS3703 belongs to Fairchild's legacy general-purpose bipolar transistor family, engineered for robustness in industrial control, power supply feedback, and signal conditioning where TO-92 form factor and PNP polarity are system constraints.

FAQ

What is the maximum continuous collector current rating for the MPS3703?

The MPS3703 has a maximum continuous collector current (I_C) rating of 800 mA at T_A = 25 °C. This rating assumes adequate PCB copper area or heatsinking to maintain junction temperature within –55 to +150 °C limits. At elevated ambient temperatures, derating applies per the 5.0 mW/°C specification - meaning usable current drops to approximately 500 mA at 85 °C ambient. The MPS3703 datasheet specifies this limit under steady-state DC conditions, not pulsed operation.

Is the MPS3703 pin-compatible with the PN2907A?

Yes, the MPS3703 and PN2907A share identical TO-92 packaging and pinout: Emitter–Base–Collector in left-to-right order when viewing the flat side with leads down. Both devices follow JEDEC TO-92 outline standards, enabling direct physical replacement in existing footprints. However, the MPS3703 has lower V_CEO (30 V vs. 60 V) and narrower h_FE range (30–150 vs. 100–300), so functional equivalence depends on circuit voltage and gain tolerance requirements.

What is the typical f_T value of the MPS3703 and how does it affect circuit design?

The MPS3703 has a specified f_T of 100 MHz at I_C = 50 mA and V_CE = 5.0 V. This unity-gain bandwidth indicates the device can provide useful small-signal gain up to approximately 10–20 MHz in practical amplifier configurations. Designers use this parameter to estimate upper frequency limits in audio preamps or pulse amplifiers - for example, achieving 20 dB gain requires operating well below f_T/10 (~10 MHz). The MPS3703's f_T supports clean reproduction of full-audio bandwidth (20 Hz–20 kHz) with ample margin.

Does the MPS3703 meet RoHS compliance and what is its lead finish?

The MPS3703 was manufactured by Fairchild prior to the 2016 ON Semiconductor acquisition and predates mandatory RoHS enforcement for legacy discretes. Original production used SnPb (tin-lead) lead finish, confirmed by historical Fairchild packaging documentation and reel labels referencing "F63TNR" process code. Aetrix Electronics supplies only fully RoHS-compliant versions, reflow-tested to IPC-J-STD-020 standards, with matte tin (Sn) plating and Pb-free solderability verified per JESD22-A112.

Can the MPS3703 be used in linear regulator pass transistor applications?

The MPS3703 can serve as a pass element in low-dropout linear regulators where load current stays below 500 mA and power dissipation remains within 300 mW - e.g., 5 V → 3.3 V conversion at 200 mA yields ~340 mW dissipation, exceeding its 625 mW P_D rating at 25 °C. For sustained linear regulation, thermal design is critical: with R_θJA = 200 °C/W, even 200 mW raises junction temperature by 40 °C above ambient. The MPS3703 is better suited to switching or bias roles than primary pass transistors in high-current LDOs.