onsemi MC7815BDTG

MC7815BDTG Linear Regulator Summary (onsemi MC7800 Family)

The MC7815BDTG is part of onsemi’s MC7800 family of monolithic, fixed-voltage linear regulator ICs, engineered for diverse electronic applications requiring reliable 15V regulation at 1A output. As a three-terminal positive voltage regulator, it is widely used in local, on-card power supply designs where stability, simplicity, and robustness are key requirements. Housed in the space-saving DPAK (TO-252-3/SC-63) surface-mount package, the device offers essential features—such as high output current capability and comprehensive internal protection—presenting a straightforward solution for system designers targeting reliable point-of-load regulation.

Main Technical Parameters of the MC7815BDTG Linear Regulator

The MC7815BDTG delivers a fixed 15V output at currents up to 1A. Input voltages are supported up to 35V, with a maximum dropout voltage typically at 2V when supplying full load. The quiescent current is 8mA, ensuring efficient operation even in low standby power environments. PSRR (Power Supply Rejection Ratio) is rated at 58dB (120Hz), enabling rejection of line noise for sensitive analog circuits. Temperature tolerance ranges from −40°C to +125°C, making it suitable for applications requiring solid performance across wide environmental conditions.

Summary Table:

Output voltage: 15V (fixed)

Output current: Up to 1A

Input voltage: Up to 35V

Dropout voltage: 2V @ 1A

Quiescent current: 8mA

PSRR: 58dB @ 120Hz

Operating temperature: −40°C to +125°C

Package: DPAK (TO-252-3/SC-63), surface mount

Characteristics and Protection Features of the MC7815BDTG Linear Regulator

Among the MC7815BDTG’s core strengths are its built-in protection mechanisms that safeguard the regulator and downstream circuitry. The device integrates:

Internal current limiting: Prevents excessive current through the regulator during load faults or short circuits.

Thermal overload protection: Shuts down operation if excessive internal heating occurs, protecting against over-temperature damage.

Output transistor safe–area compensation: Ensures reliable operation and reduces short-circuit current according to the voltage across the pass transistor.

These features significantly reduce the need for additional external protection circuitry, streamlining PCB design and enhancing reliability in compact form factors.

Operational Attributes of the MC7815BDTG Linear Regulator

The regulator’s electrical performance is designed to maintain tight output regulation across varying input voltages and load conditions. Both line and load regulation are specified at constant junction temperatures, with pulse testing applied for accuracy. The MC7815BDTG’s load regulation ensures minimal voltage deviation across a wide range of currents, while its line regulation maintains consistent output as input supply fluctuates. Long-term stability and low output noise voltage further contribute to its suitability in precision analog and mixed-signal designs.

Several figures from the MC7800 series’ characterization data highlight:

Peak output current as a function of input/output differential voltage

Ripple rejection versus output voltage and frequency

Output voltage response to junction temperature

Output impedance and quiescent current over temperature

These metrics are essential for engineers predicting regulator behavior in complex supply chains and high-density boards.

Physical Dimensions and Packaging of the MC7815BDTG Linear Regulator

The MC7815BDTG is supplied in a DPAK (TO-252-3/SC-63) surface-mount package, facilitating compatibility with automated assembly processes. The package’s thermal characteristics ensure good heat dissipation when mounted according to recommended PCB layouts. Mechanical drawings are provided to support accurate footprint design and ensure reliable soldering. The device is also available in other MC7800 family packages, including D²PAK and TO-220, which can be considered when alternate mounting or thermal constraints exist.

Key considerations include the DPAK’s single gauge design, mounting pad recommendations, and pin assignment: input, ground, and output terminals. Proper heatsinking should be incorporated for applications approaching the regulator’s maximum dissipation.

Usage Instructions for the MC7815BDTG Linear Regulator

Design scenarios utilizing MC7815BDTG range from simple point-of-load voltage regulation in embedded systems to more advanced current source implementations. In basic applications, minimal external components are required. Bypass capacitors on the input, particularly when supply lines are long, can improve transient response and high-frequency stability. While output capacitors are not strictly necessary for regulator stability, they can enhance transient performance.

Engineering logic may also use MC7815BDTG as a current source by including suitable resistors and, with augmenting circuitry, as an adjustable voltage source. For higher current outputs, designers can employ external PNP transistors for current boosting, though such configurations require attention to short-circuit protection design.

Thermal design is crucial, with attention to ambient temperature, PCB copper area, and required power dissipation. Application figures illustrate worst-case power dissipation with various mounting configurations, allowing engineers to predict regulator performance under real-world conditions and ensure reliable operation in their target environment.

Environmental Standards and Compliance Data for the MC7815BDTG Linear Regulator

MC7815BDTG complies with RoHS3 and REACH criteria, supporting integration in environmentally regulated products. The device boasts a Moisture Sensitivity Level (MSL) of 1 (unlimited), signifying robust handling and storage capabilities in manufacturing flows. Export classifications including ECCN (EAR99) and HTSUS (8542.39.0001) are provided to assist in supply chain logistics and regulatory compliance.

Alternative/Replacement Options for the MC7815BDTG Linear Regulator

With MC7815BDTG status as obsolete, engineers seeking alternatives may evaluate other MC7800 series variants with similar voltage and current specifications, such as MC7815 in the TO-220 or D²PAK package. Other related series, MC7800A, MC7800AE, and automotive-qualified NCV7800 devices, offer comparable electrical and protection features with diverse mechanical options and, in the case of NCV7800, extended automotive reliability standards. Key selection criteria should focus on package compatibility, thermal characteristics, voltage tolerance, and regulatory status.

Conclusion

The MC7815BDTG from onsemi’s MC7800 family provides a fully integrated solution for fixed 15V, 1A linear regulation, marked by robust internal protection, high noise rejection, and flexible mounting options in a compact DPAK package. While now obsolete, the MC7815BDTG’s design principles—ease of use, comprehensive protection, and straightforward performance—continue to set reference standards for engineers selecting linear regulators for analog, embedded, and industrial applications. Awareness of its specifications and available alternatives ensures optimal component selection for reliable, compliant, and efficient power system design.