LM7905CT Linear Voltage Regulator -5V 1A Equivalent & Substitute Parts

Part Overview

The LM7905CT is a linear voltage regulator IC manufactured by onsemi, designed to provide a fixed negative 5V output at 1A current capacity in a TO-220-3 package. This part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. The LM7905CT serves applications requiring stable negative voltage regulation with integrated over-temperature and short-circuit protection.

Key Parameters

Parameter	Value
Output Configuration	Negative
Output Type	Fixed
Output Voltage	-5V
Current - Output	1A
Voltage - Input (Max)	-35V
Voltage Dropout (Max)	2V @ 1A (Typ)
PSRR	60dB (120Hz)
Operating Temperature	0°C ~ 125°C
Package / Case	TO-220-3
Mounting Type	Through Hole
Protection Features	Over Temperature, Short Circuit

Substitute Part Grouping Explanation

Substitution for the LM7905CT is determined by the following critical parameters:

Output Configuration & Voltage: All substitutes must provide negative fixed -5V output
Current Capacity: Minimum 1A output current required; higher ratings are acceptable
Package Type: TO-220-3 form factor for mechanical and thermal compatibility
Input Voltage Rating: Maximum -35V input specification or higher
Protection Features: Over-temperature and short-circuit protection required
Operating Temperature Range: 0°C to 125°C minimum coverage
Mounting Type: Through-hole configuration for PCB compatibility

Substitute parts are grouped into two categories: direct equivalents (matching all primary specifications) and compatible alternatives (exceeding minimum specifications while maintaining functional compatibility).

Parameter Comparison

Part Number	Manufacturer	Output Current	Voltage Dropout (Max)	PSRR	Operating Temp	Product Status	Protection Features
LM7905CT	onsemi	1A	2V @ 1A	60dB (120Hz)	0°C ~ 125°C	Obsolete	Over Temperature, Short Circuit
MC7905CTG	onsemi	1A	1.3V @ 1A	70dB (120Hz)	0°C ~ 125°C	Active	Over Current, Over Temperature
MC7905BTG	onsemi	1A	1.3V @ 1A	70dB (120Hz)	-40°C ~ 125°C	Active	Over Current, Over Temperature
L7905ACV	STMicroelectronics	1.5A	1.4V @ 1A	60dB (120Hz)	0°C ~ 125°C	Active	Over Temperature, Short Circuit
L7905CV	STMicroelectronics	1.5A	1.4V @ 1A	60dB (120Hz)	0°C ~ 125°C	Active	Over Temperature, Short Circuit
LM7905CT/NOPB	Texas Instruments	1.5A	1.1V @ 1A	66dB (120Hz)	0°C ~ 125°C	Active	Over Temperature, Short Circuit
UA7905CKCS	Texas Instruments	1.5A	1.1V @ 1A	60dB (120Hz)	0°C ~ 125°C	Last Time Buy	Over Current, Over Temperature, Short Circuit

Engineering Selection Recommendations

Direct Equivalent (onsemi Source): MC7905CTG is the active production equivalent from onsemi. It maintains the same 1A output current and TO-220-3 package while offering improved voltage dropout (1.3V vs 2V) and higher PSRR (70dB vs 60dB). This part is ROHS3 compliant and actively manufactured.

Extended Temperature Range Alternative: MC7905BTG provides identical electrical specifications to MC7905CTG with extended operating temperature range (-40°C to 125°C), suitable for industrial and automotive applications requiring wider temperature coverage.

Higher Current Capacity Alternatives: L7905ACV and L7905CV from STMicroelectronics provide 1.5A output current capacity in the same TO-220-3 package. Both are ROHS3 compliant and actively produced. These parts are suitable for applications requiring additional current margin.

Texas Instruments Options: LM7905CT/NOPB and UA7905CKCS offer 1.5A output with superior voltage dropout performance (1.1V). LM7905CT/NOPB is actively produced and ROHS3 compliant. UA7905CKCS is classified as Last Time Buy, indicating limited future availability.

All substitute parts maintain the required -5V fixed output, TO-220-3 package configuration, and protection features necessary for functional compatibility with the obsolete LM7905CT.

Frequently Asked Questions (FAQ)

Q: Can I use a substitute part with higher output current rating than the LM7905CT? A: Yes. Parts rated for 1.5A output current (L7905ACV, L7905CV, LM7905CT/NOPB, UA7905CKCS) are functionally compatible with applications designed for 1A. The higher current rating provides additional design margin without affecting circuit operation.

Q: Are all substitute parts available in the same TO-220-3 package? A: Yes. All listed substitute parts use the TO-220-3 package configuration, ensuring mechanical and thermal compatibility with existing PCB layouts and heatsinking arrangements.

Q: What is the difference between MC7905CTG and MC7905BTG? A: Both parts are electrically identical with 1A output current and 1.3V dropout voltage. MC7905BTG extends the operating temperature range to -40°C to 125°C, compared to MC7905CTG at 0°C to 125°C. Select MC7905BTG for applications requiring operation below 0°C.

Q: Why do some substitutes have lower voltage dropout specifications? A: Improved voltage dropout performance (1.3V or 1.1V vs 2V) represents enhanced regulator design in newer production parts. Lower dropout voltage reduces heat dissipation and improves efficiency, providing a performance advantage over the obsolete LM7905CT.

Q: Is the UA7905CKCS suitable for new designs? A: UA7905CKCS is classified as Last Time Buy, indicating limited manufacturing availability. For new designs, select from actively produced alternatives: MC7905CTG, MC7905BTG, L7905ACV, L7905CV, or LM7905CT/NOPB.

Q: Do all substitute parts include the same protection features as the LM7905CT? A: All substitute parts include over-temperature protection. MC7905CTG, MC7905BTG, and UA7905CKCS add over-current protection. Short-circuit protection is present in LM7905CT, L7905ACV, L7905CV, LM7905CT/NOPB, and UA7905CKCS. Verify specific protection requirements for your application.

Q: Are substitute parts RoHS compliant? A: MC7905CTG, MC7905BTG, L7905ACV, L7905CV, LM7905CT/NOPB, and UA7905CKCS are all ROHS3 compliant. The obsolete LM7905CT is not RoHS compliant, making compliant substitutes necessary for new production.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message