LM7905CT Linear Voltage Regulator -5V 1.5A Equivalent & Substitute Parts

Part Overview

The LM7905CT is a negative fixed linear voltage regulator manufactured by Texas Instruments, designed to deliver -5V at 1.5A output current in a TO-220-3 through-hole package. This device is classified as Last Time Buy, indicating limited availability from the original manufacturer. Identifying equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain flexibility for applications requiring negative voltage regulation.

Substiute Parts

LM7905CT

Texas InstrumentsIn Stock: 16760LM7905CT Datasheet

Current PartRFQ

LM7905CT/NOPB

Texas InstrumentsIn Stock: 1338LM7905CT/NOPB Datasheet

DirectRFQ

L7905ACV

STMicroelectronicsIn Stock: 11263L7905ACV Datasheet

MFR RecommendedRFQ

L7905CV

STMicroelectronicsIn Stock: 88829L7905CV Datasheet

MFR RecommendedRFQ

MC7905BTG

onsemiIn Stock: 2072MC7905BTG Datasheet

MFR RecommendedRFQ

MC7905CTG

onsemiIn Stock: 4068MC7905CTG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

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

• Output Voltage: Must be -5V fixed
• Output Current: Minimum 1.5A (equal or greater)
• Package Type: TO-220-3 through-hole mounting
• Output Configuration: Negative polarity
• Protection Features: Over Temperature and Short Circuit protection
• RoHS Compliance: ROHS3 Compliant
• Mounting Type: Through Hole

Substitute parts are grouped into two categories:

Direct Equivalent: Parts with identical electrical specifications and product status (Active).

Functional Equivalent: Parts meeting or exceeding all critical parameters but with variations in secondary specifications such as maximum input voltage, quiescent current, or PSRR, provided they maintain compatibility with the application requirements.

Parameter Comparison

Engineering Selection Recommendations

LM7905CT/NOPB (Texas Instruments, Active): Direct equivalent with identical electrical specifications and Active product status. Recommended as primary substitute when LM7905CT Last Time Buy stock is depleted. Maintains full compatibility with existing designs.

L7905ACV and L7905CV (STMicroelectronics, Active): Functionally equivalent alternatives meeting all critical parameters. Both devices support higher maximum input voltage (-35V vs -25V), providing enhanced design margin. L7905CV offers significantly higher inventory availability (88791 Pcs). Suitable for applications where input voltage range does not exceed -35V. PSRR is 6dB lower than LM7905CT; verify acceptability in noise-sensitive applications.

MC7905BTG and MC7905CTG (onsemi, Active): Functionally equivalent with output current rated at 1A, which is below the LM7905CT 1.5A specification. These devices are suitable only for applications requiring maximum output current of 1A or less. MC7905BTG supports extended operating temperature range (-40°C ~ 125°C). Both offer superior PSRR (70dB vs 66dB). Over Current protection is included in addition to Over Temperature protection.

All substitute parts maintain ROHS3 compliance, TO-220-3 package compatibility, and through-hole mounting configuration. Selection should be based on specific application requirements for output current, input voltage range, and operating temperature.

Frequently Asked Questions (FAQ)

Q: Can MC7905BTG or MC7905CTG replace LM7905CT in all applications?

A: No. MC7905BTG and MC7905CTG are rated for 1A maximum output current, while LM7905CT is rated for 1.5A. These onsemi devices are suitable only for applications requiring 1A or less. If your design requires 1.5A output current, use LM7905CT/NOPB, L7905ACV, or L7905CV instead.

Q: What is the difference between L7905ACV and L7905CV?

A: Both are STMicroelectronics devices with identical electrical specifications. The primary difference is inventory availability: L7905CV has significantly higher stock (88791 Pcs vs 11200 Pcs). Both support -35V maximum input voltage and are functionally equivalent to LM7905CT for applications within this voltage range.

Q: Are all substitute parts pin-compatible with LM7905CT?

A: Yes. All listed substitute parts use the TO-220-3 package with identical pin configuration and through-hole mounting, ensuring direct mechanical and electrical compatibility.

Q: Why does LM7905CT have lower quiescent current than STMicroelectronics alternatives?

A: Quiescent current (Iq) varies by manufacturer design. LM7905CT and LM7905CT/NOPB specify 1 mA, while L7905ACV and L7905CV specify 3 mA. This difference affects standby power consumption. For battery-powered or low-power applications, verify that the higher Iq of STMicroelectronics devices is acceptable.

Q: Can I use L7905ACV or L7905CV if my input voltage is limited to -25V?

A: Yes. L7905ACV and L7905CV are rated for -35V maximum input voltage, which exceeds the -25V requirement. They will operate correctly at -25V input with no performance degradation.

Q: What is the significance of PSRR differences between substitute parts?

A: PSRR (Power Supply Rejection Ratio) measures the regulator's ability to reject input voltage ripple. LM7905CT and LM7905CT/NOPB specify 66dB, while MC7905BTG and MC7905CTG specify 70dB (better rejection). STMicroelectronics devices specify 60dB (lower rejection). For noise-sensitive analog circuits, verify that the PSRR of your selected substitute meets application requirements.

Q: Is MC7905BTG suitable for extended temperature range applications?

A: MC7905BTG supports -40°C ~ 125°C operating temperature, compared to 0°C ~ 125°C for LM7905CT. If your application requires operation below 0°C, MC7905BTG is suitable, provided the 1A output current limitation is acceptable.