LP38855S-0.8/NOPB Equivalent & Substitute Parts

Part Overview

The LP38855S-0.8/NOPB is a linear voltage regulator IC from Texas Instruments designed for positive fixed output applications. It delivers 1.5A output current at a fixed 0.8V output voltage in a TO-263 (DDPAK-5) surface mount package. The device is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support, production continuity, and system maintenance.

Substiute Parts

LP38855S-0.8/NOPB

Texas InstrumentsIn Stock: 1178LP38855S-0.8/NOPB Datasheet

Current PartRFQ

LP38842S-0.8/NOPB

Texas InstrumentsIn Stock: 1248LP38842S-0.8/NOPB Datasheet

Parametric EquivalentRFQ

MCP1827T-0802E/ET

Microchip TechnologyIn Stock: 1745MCP1827T-0802E/ET Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LP38855S-0.8/NOPB are identified based on the following critical parameters that must align for functional equivalence:

• Output voltage: 0.8V fixed
• Output current capability: 1.5A minimum
• Package type: TO-263 (DDPAK-5) surface mount
• Operating temperature range: -40°C to 125°C
• Output configuration: Positive fixed regulator
• Control features: Enable function

The two substitute parts listed meet these core electrical and mechanical requirements while offering improved product status and compliance characteristics.

Parameter Comparison

Engineering Selection Recommendations

LP38842S-0.8/NOPB is the primary parametric equivalent from Texas Instruments. This part maintains the same manufacturer lineage, identical output specifications, and identical package configuration. The LP38842S-0.8/NOPB is currently in active production status, ensuring long-term availability. It carries ROHS3 compliance, addressing regulatory requirements that the obsolete LP38855S-0.8/NOPB does not meet. The quiescent current is significantly reduced (30 µA versus 300 µA), providing improved power efficiency in standby conditions. The dropout voltage is slightly higher at 0.315V, which remains acceptable for most 0.8V output applications.

MCP1827T-0802E/ET from Microchip Technology is an alternative substitute that meets all core electrical and mechanical requirements. This device is also in active production with ROHS3 compliance. The MCP1827T-0802E/ET offers superior moisture sensitivity characteristics (MSL 1 versus MSL 3), beneficial for high-humidity storage and assembly environments. It includes additional control features (Power Good output) and protection (Under Voltage Lockout), providing enhanced system monitoring capabilities. The maximum input voltage is rated at 6V, offering slightly greater input headroom. The dropout voltage is higher at 0.6V, which may require evaluation in applications with tight input-to-output voltage margins.

For designs requiring direct pin-compatible replacement with minimal circuit modification, the LP38842S-0.8/NOPB is the recommended choice. For applications benefiting from enhanced protection features and superior moisture handling, the MCP1827T-0802E/ET is suitable.

Frequently Asked Questions (FAQ)

Q: Can LP38842S-0.8/NOPB directly replace LP38855S-0.8/NOPB without circuit changes?

A: Yes. Both parts share identical output voltage (0.8V), output current (1.5A), package type (TO-263 DDPAK-5), and pin configuration. The LP38842S-0.8/NOPB is a direct functional substitute. Verify that the slightly higher dropout voltage (0.315V versus 0.180V) is acceptable for your input voltage range.

Q: What is the key difference between LP38842S-0.8/NOPB and MCP1827T-0802E/ET?

A: Both deliver 1.5A at 0.8V in TO-263 packages. The LP38842S-0.8/NOPB maintains Texas Instruments design continuity with lower dropout voltage. The MCP1827T-0802E/ET offers additional features (Power Good output, UVLO protection) and superior moisture sensitivity (MSL 1). The MCP1827T-0802E/ET has higher dropout voltage (0.6V), requiring verification in low input voltage applications.

Q: Are there packaging differences between these substitutes?

A: All three parts use TO-263 (DDPAK-5) surface mount packages with identical mechanical footprints. The LP38855S-0.8/NOPB and LP38842S-0.8/NOPB are supplied in different packaging formats (standard versus tube), but the component itself is identical. The MCP1827T-0802E/ET is supplied in Tape & Reel format. PCB layout and thermal management considerations remain consistent across all three parts.

Q: Why is RoHS compliance important for this substitution?

A: The LP38855S-0.8/NOPB is RoHS non-compliant, which restricts its use in new designs and applications subject to RoHS regulations. Both substitute parts (LP38842S-0.8/NOPB and MCP1827T-0802E/ET) are ROHS3 compliant, ensuring compatibility with current manufacturing standards and regulatory requirements in most markets.

Q: Which substitute has the lowest quiescent current?

A: The LP38842S-0.8/NOPB has the lowest quiescent current at 30 µA, compared to 300 µA for the LP38855S-0.8/NOPB and 220 µA for the MCP1827T-0802E/ET. This makes the LP38842S-0.8/NOPB the preferred choice for battery-powered or low-power standby applications.

Q: Can MCP1827T-0802E/ET be used in applications requiring the lowest dropout voltage?

A: No. The MCP1827T-0802E/ET has the highest dropout voltage at 0.6V @ 1.5A. For applications with tight input-to-output voltage margins, the LP38842S-0.8/NOPB (0.315V dropout) or the original LP38855S-0.8/NOPB (0.180V dropout) are more suitable. Verify your specific input voltage range before selecting based on dropout voltage.