NCP1117LPST15T3G Equivalent & Substitute Parts

Part Overview

The NCP1117LPST15T3G is a linear voltage regulator IC from onsemi, designed for positive fixed output applications. This device delivers 1A output current with a fixed 1.5V output voltage in a SOT-223 surface mount package. The part is classified as obsolete, making identification of suitable alternatives essential for ongoing design support and procurement planning. The NCP1117LPST15T3G operates across an input voltage range up to 18V with a maximum dropout voltage of 1.4V at full load, incorporating over-current and over-temperature protection features.

Substiute Parts

NCP1117LPST15T3G

onsemiIn Stock: 5431NCP1117LPST15T3G Datasheet

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NCP1117LPSTADT3G

onsemiIn Stock: 5000506NCP1117LPSTADT3G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

The NCP1117LPSTADT3G qualifies as a substitute based on the following alignment of critical electrical and mechanical parameters:

Matching Parameters:

• Manufacturer: onsemi (same manufacturer, same product family)
• Base Product Number: NCP1117 (identical regulator platform)
• Package / Case: TO-261-4, TO-261AA (SOT-223) — identical mechanical footprint
• Voltage - Input (Max): 18V — identical maximum input voltage
• Current - Output: 1A — identical output current rating
• Voltage Dropout (Max): 1.4V @ 1A — identical dropout specification
• Operating Temperature: 0°C ~ 125°C — identical temperature range
• Mounting Type: Surface Mount — identical mounting technology
• Protection Features: Over Current, Over Temperature — identical protection
• PSRR: 60dB (120Hz) — identical power supply rejection ratio
• RoHS Status: ROHS3 Compliant — identical compliance certification

Functional Difference: The NCP1117LPSTADT3G features adjustable output voltage (1.25V to 16.6V) versus the fixed 1.5V output of the NCP1117LPST15T3G. This difference permits the substitute to function in the original application when configured to the required 1.5V output through external resistor divider networks.

Parameter Comparison

Engineering Selection Recommendations

The NCP1117LPSTADT3G is an active product from the same manufacturer and product family, providing continuity for designs currently using the obsolete NCP1117LPST15T3G. Both devices share identical mechanical packaging (SOT-223), electrical ratings (1A output, 18V maximum input, 1.4V dropout), and protection features. The substitute maintains ROHS3 compliance and operates across the same temperature range.

The primary design consideration is the transition from fixed to adjustable output configuration. The NCP1117LPSTADT3G requires external resistor divider networks to establish the 1.5V output voltage, whereas the original part provides this voltage internally. This substitution is suitable for applications where circuit board redesign to accommodate output voltage adjustment circuitry is feasible. The substitute's lower quiescent current (50 µA versus 700 µA) provides an additional benefit for battery-powered or low-power standby applications.

Frequently Asked Questions (FAQ)

Q: Can the NCP1117LPSTADT3G directly replace the NCP1117LPST15T3G without circuit modifications?

A: No. The NCP1117LPSTADT3G requires external resistor divider networks to set the output voltage to 1.5V. Direct pin-for-pin substitution will not produce the correct output voltage. Circuit redesign is necessary.

Q: Are the package dimensions identical between these two parts?

A: Yes. Both parts use the SOT-223 package (TO-261-4, TO-261AA case outline), providing identical mechanical footprint and pin spacing.

Q: What is the advantage of using the adjustable version?

A: The NCP1117LPSTADT3G offers design flexibility for applications requiring multiple output voltages and features significantly lower quiescent current (50 µA versus 700 µA), beneficial for low-power applications.

Q: Are both parts RoHS compliant?

A: Yes. Both the NCP1117LPST15T3G and NCP1117LPSTADT3G are ROHS3 compliant.

Q: Why is the original part listed as obsolete?

A: The NCP1117LPST15T3G is classified as obsolete by onsemi. The NCP1117LPSTADT3G remains in active production, making it the recommended path for new designs and ongoing procurement.

Q: Do both parts have identical electrical ratings?

A: Both parts share identical maximum input voltage (18V), output current (1A), dropout voltage (1.4V @ 1A), operating temperature range (0°C to 125°C), and protection features (over-current and over-temperature). The key difference is output voltage configuration: fixed versus adjustable.