onsemi MC78M09BDTRK

Overview

MC78M09BDTRK from onsemi is a 500 mA, fixed +9.0 V positive voltage regulator in DPAK-3 (TO-252) package, featuring internal thermal shutdown, short-circuit current limiting, and safe-area compensation for rugged local regulation. It delivers stable output across −40°C to +125°C, supports input voltages up to 35 V, and is widely used in automotive body control modules and industrial power supplies.

For engineers reviewing the MC78M09BDTRK datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed −40°C to +125°C operation, ±5% output voltage tolerance at 350 mA, dropout voltage of 2.0 V, ripple rejection ≥56 dB at 120 Hz, and Pb-free DPAK-3 thermal performance with θ_JC = 5.0°C/W.

Technical Context

The MC78M09BDTRK implements a monolithic series pass regulator architecture with built-in protection circuitry: thermal overload shutdown activates above +150°C junction temperature, short-circuit current limit holds peak output at 350 mA under fault, and safe-area compensation dynamically reduces short-circuit current as V_IN−V_OUT increases.

It operates without external components for basic regulation but requires an input bypass capacitor (≥0.33 µF) when connected via long traces or driving large capacitive loads. Its fixed 9.0 V output is trimmed at 25°C to 8.64–9.45 V, with line regulation ≤6.0 mV and load regulation ≤25 mV over full operating conditions.

Key Specifications

Pinout & Package

DPAK-3 (TO-252) surface-mount package with exposed thermal pad (Pin 2), optimized for PCB copper area heat spreading. Pin 1 = Input, Pin 2 = Ground (and thermal tab), Pin 3 = Output.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear regulator applications.

Compared with MC78M09CDTRKG, the MC78M09BDTRK adds −40°C capability critical for cold-start operation; versus NCV78M09BDTRKG, it lacks AEC-Q100 certification but shares all electrical and thermal behavior - making it ideal for non-OEM industrial designs needing extended temperature support without automotive overhead.

Availability

MC78M09BDTRK is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLCs, and medical monitoring equipment requiring stable component supply across −40°C to +125°C operating ranges.

Supply support for MC78M09BDTRK 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 delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MC78M00 series was designed as a rugged, drop-in replacement for legacy 78xx regulators - optimized for local point-of-load regulation in harsh environments with integrated protection and extended temperature support.

FAQ

What is the guaranteed output voltage tolerance for MC78M09BDTRK over its full operating temperature range?

The MC78M09BDTRK guarantees an output voltage of 8.55 V to 9.45 V (±5%) across −40°C to +125°C junction temperature and 5.0 mA to 350 mA load current, per onsemi's Electrical Characteristics table on page 4 of the datasheet. This tolerance includes initial accuracy, line/load regulation, and temperature drift - no binning or external trimming required.

Can MC78M09BDTRK operate with an input voltage of 11 V?

No - MC78M09BDTRK requires a minimum input voltage of 11.5 V for guaranteed regulation at full load (350 mA), as specified in the "Output Voltage Variation" test condition on page 4. At 11 V input, dropout exceeds specification and output may fall out of regulation, especially at elevated temperatures or higher currents.

Does MC78M09BDTRK require an input bypass capacitor, and if so, what value is recommended?

Yes - onsemi recommends a minimum 0.33 µF tantalum, mylar, or low-ESR ceramic capacitor placed directly across the input pins (Pin 1 to Pin 2) with shortest possible leads. This stabilizes operation under high-frequency noise or long trace inductance, preventing oscillation - especially critical when powering from switch-mode supplies or with >10 cm interconnects.

What is the maximum power dissipation of MC78M09BDTRK in DPAK-3 package at 25°C ambient with standard PCB copper?

With 2 oz. copper and 25 mm² thermal pad area, MC78M09BDTRK achieves θ_JA ≈ 92°C/W (per datasheet page 2), allowing ~0.55 W continuous dissipation at T_A = 25°C before reaching T_J = 150°C. At 500 mA load and 2.0 V dropout, P_D = 1.0 W - thus active heatsinking or larger copper is required for full-rated current at elevated ambient.

Is MC78M09BDTRK pin-compatible with other DPAK-3 linear regulators like LM2940CT-9.0?

No - MC78M09BDTRK uses Pin 1 = Input, Pin 2 = Ground/Tab, Pin 3 = Output; LM2940CT-9.0 uses Pin 1 = Ground, Pin 2 = Input, Pin 3 = Output. The pinout reversal means direct PCB replacement is not possible without layout modification - verify pin mapping before substitution.