Part Number: LM78M05CMWC
Function: 3-Terminal Positive Voltage Regulator
Package: TO-220, TO-252, and PFM D-PAK Type
Manufacturer: Texas Instruments
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Description
The LM341 and LM78M05CMWC, LM78M05 series of three-terminal positive voltage regulators employ built-in current limiting, thermal shutdown, and safe-operating area protection which makes them virtually immune to damage from output overloads. With adequate heatsinking, they can deliver in excess of 0.5A output current. Typical applications would include local (on-card) regulators which can eliminate the noise and degraded performance associated with single-point regulation.
Key Features
- Fixed 5V output voltage
- Output current capability > 0.5A (with proper heatsinking)
- No external components required for basic operation
- Internal thermal shutdown protection
- Internal current limiting (short-circuit protection)
- Safe Operating Area (SOA) protection for output transistor
- Available in multiple fixed voltage variants (5V, 12V, 15V)
Pinout
Design Considerations
- Thermal Dissipation: Power loss = (Vin – 5V) × Iout → ensure proper heatsink
- Dropout Margin: Maintain Vin ≥ ~7V for stable regulation
- Efficiency: Low compared to switching regulators, especially at high Vin
- Noise Performance: Very low output noise, suitable for analog circuits
- Stability: Requires proper bypass capacitors close to pins
Advantages
- Extremely simple implementation
- Robust protection features
- Low noise compared to switching regulators
- High reliability and wide usage history
Limitations
- Low efficiency at high input-output voltage differential
- Requires thermal management at higher currents
- Not suitable for battery-powered high-efficiency designs
- Relatively high dropout compared to modern LDOs
Typical Applications
- Microcontroller and logic supply (5V rail)
- On-board regulation (point-of-load)
- Linear post-regulation after DC-DC converters
- Analog and mixed-signal circuits requiring low noise
- Industrial and consumer electronics
Alternative / Equivalent Devices
- LM7805 – Standard 1A version
- LM1117-5.0 – Low dropout regulator
- AMS1117-5.0 – Popular LDO alternative
- TLV1117 – Improved LDO performance
- DC-DC Buck Converters – For higher efficiency applications
Other data sheets are available within the file:
LM341, LM341T-12, LM341T-15, LM341T-15/NOPB, LM341T-5.0
LM78M05CMWC Datasheet PDF Download
