onsemi MPS6729G

Overview

MPS6729G from onsemi is a PNP silicon bipolar junction transistor designed for general-purpose linear and switching amplifier applications, with −80 V collector-emitter breakdown voltage, −500 mA continuous collector current, 1.0 W total device dissipation at TA = 25°C, and TO-92 package. It operates across −55°C to +150°C junction temperature range and is commonly used in low-power audio preamplifier stages and relay driver circuits.

For engineers reviewing the MPS6729G datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, guaranteed V(BR)CEO ≥ −80 V, hFE ≥ 80 at IC = −50 mA, VCE(sat) ≤ −0.5 V under IC/IB = 25, and thermal resistance RJA = 125°C/W for ambient-limited designs.

Technical Context

The MPS6729G is a discrete PNP BJT optimized for medium-current, medium-voltage amplification and switching. Its DC current gain (hFE) ranges from 80 to 250 depending on operating point, with saturation behavior characterized at IC = −250 mA and IB = −10 mA. The device exhibits a base-emitter on voltage of up to −1.2 V and collector-base capacitance of 30 pF at −10 V reverse bias.

Thermal design is constrained by RJC = 50°C/W and RJA = 125°C/W, requiring careful PCB copper area allocation when operating near its 2.5 W TC = 25°C dissipation limit. Safe operating area (SOA) curves confirm second-breakdown immunity up to −100 mA at −80 V in DC conditions, supporting robust operation in inductive load switching.

Key Specifications

Pinout & Package

Package: TO-92 (Case 29-10, Style 1), Pb-free, through-hole mounting. Standard lead form with bent leads; marking includes "MPS6729" and date code.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP BJT amplifier and switching applications.

Compared with BC557B and MPSA92, the MPS6729G uniquely balances −80 V blocking, −500 mA current, and 1.0 W ambient-rated dissipation in TO-92-making it optimal for 24–48 V industrial interface and audio amplifier roles where both voltage margin and thermal performance are critical.

Availability

MPS6729G is available at Aetrix Electronics and suitable for industrial control interfaces, low-power audio signal conditioning, and relay/LED driver circuits requiring stable component supply and long-term obsolescence support.

Supply support for MPS6729G 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MPS6729G belongs to onsemi's legacy discrete transistor portfolio, engineered for cost-sensitive, high-reliability linear and switching applications in industrial automation and infrastructure equipment.

FAQ

What is the maximum continuous collector current rating for the MPS6729G?

The MPS6729G is rated for −500 mA continuous collector current (IC) at TA = 25°C. This rating assumes adequate PCB copper area to maintain junction temperature within −55°C to +150°C limits. Derating is required above 25°C ambient per the 8.0 mW/°C specification, and actual usable current drops significantly above 60°C ambient without heatsinking.

Is the MPS6729G pin-compatible with the MPS6729 (non-G) variant?

Yes, the MPS6729G is a direct Pb-free replacement for the MPS6729, sharing identical TO-92 package dimensions, pinout (Emitter-Base-Collector on pins 1-2-3), electrical specifications, and thermal characteristics. The "G" suffix denotes RoHS-compliant packaging only; no functional or layout changes are required when substituting MPS6729G for MPS6729.

What is the typical DC current gain (hFE) of the MPS6729G at low collector current?

The MPS6729G exhibits hFE ≥ 80 at IC = −50 mA and VCE = −1.0 V, and hFE ≥ 50 at IC = −250 mA under the same VCE condition. Gain decreases with increasing current and temperature-Figure 1 in the datasheet confirms hFE ≈ 120 at −100 mA and 25°C, dropping to ~60 at 125°C, which must be accounted for in precision bias designs.

Can the MPS6729G be used in switching power supply feedback circuits?

The MPS6729G is not recommended for high-frequency switching power supply feedback due to its 20 MHz fT and lack of specified switching time parameters (ton/toff). While it can function in low-frequency (<100 kHz) error amplifier stages, dedicated high-speed transistors like the MMBT3906 or SMMBT3906 offer superior bandwidth and tighter gain tolerance for closed-loop stability.

Does the MPS6729G have built-in ESD protection?

No, the MPS6729G does not incorporate on-die ESD protection structures. Its absolute maximum ratings specify only junction temperature and voltage limits; handling and PCB layout must follow standard ESD control practices (e.g., IEC 61000-4-2 Level 2 compliance requires external series resistors and/or TVS diodes on base and emitter lines when exposed to user-accessible ports).