LM2991S/NOPB Equivalent & Substitute Parts

Part Overview

The LM2991S/NOPB is a linear voltage regulator IC designed for negative adjustable output applications. This Surface Mount device delivers 1A output current in a TO-263 (DDPAK-5) package and operates across an input voltage range of -26V maximum with adjustable output from -3V to -24V. The regulator includes integrated over-temperature and short-circuit protection with enable control features.

The LM2991S/NOPB is currently in Active product status with 5200 pieces available in inventory. Identifying equivalent substitute parts is necessary for supply chain continuity, design flexibility, and long-term component availability planning.

Substiute Parts

LM2991S/NOPB

Texas InstrumentsIn Stock: 5217LM2991S/NOPB Datasheet

Current PartRFQ

LM2991S

Texas InstrumentsIn Stock: 12391LM2991S Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LM2991S/NOPB are identified based on strict electrical and mechanical parameter matching. The following criteria determine substitution eligibility:

Critical Matching Parameters:

• Output Configuration: Negative
• Output Type: Adjustable
• Number of Regulators: 1
• Voltage - Input (Max): -26V
• Voltage - Output Range: -3V to -24V
• Current - Output: 1A
• Voltage Dropout (Max): 1V @ 1A
• Package / Case: TO-263-6, D2PAK (5 Leads + Tab)
• Mounting Type: Surface Mount

All substitute parts must match these parameters exactly to ensure functional and mechanical compatibility within the same application circuit.

Parameter Comparison

Engineering Selection Recommendations

The LM2991S is a direct parametric equivalent to the LM2991S/NOPB. Both parts are manufactured by Texas Instruments and share identical electrical specifications and mechanical packaging.

Product Status Consideration: The LM2991S/NOPB maintains Active status with 5200 pieces in stock. The LM2991S is designated Last Time Buy status with 12300 pieces available. For new designs or long-term production requirements, the Active status part (LM2991S/NOPB) is preferred. For immediate availability or existing inventory management, the LM2991S remains functionally equivalent.

Compliance & Certification: Both parts are ROHS3 Compliant, REACH Unaffected, and carry identical MSL ratings. No compliance barriers exist between these parts.

Frequently Asked Questions (FAQ)

Q: Can LM2991S be used as a direct replacement for LM2991S/NOPB?

A: Yes. Both parts are parametrically identical across all electrical and mechanical specifications. The primary difference is product status: LM2991S/NOPB is Active, while LM2991S is Last Time Buy. Functionally, they are interchangeable in the same circuit application.

Q: What determines if a part can substitute for the LM2991S/NOPB?

A: Substitute parts must match all critical parameters: negative output configuration, adjustable output type, 1A output current, -26V maximum input voltage, -3V to -24V output range, 1V maximum dropout at 1A, and TO-263 (DDPAK-5) Surface Mount package. Any deviation in these parameters disqualifies a part from substitution.

Q: Are there package compatibility concerns between LM2991S/NOPB and LM2991S?

A: No. Both parts use identical TO-263-6, D2PAK (5 Leads + Tab) packaging. PCB footprints, lead spacing, and mounting procedures are identical. No layout or assembly modifications are required.

Q: What is the significance of Last Time Buy status for LM2991S?

A: Last Time Buy indicates the manufacturer will discontinue production after current inventory is depleted. For new designs or applications requiring long-term component availability, the Active status LM2991S/NOPB is the recommended choice. Existing designs using LM2991S should plan transition strategies.

Q: Do both parts meet the same environmental and compliance standards?

A: Yes. Both LM2991S/NOPB and LM2991S are ROHS3 Compliant, REACH Unaffected, and carry MSL 3 (168 Hours) ratings. No environmental or regulatory differences exist between the parts.