REG1117 Linear Voltage Regulator IC Equivalent & Substitute Parts

Part Overview

The REG1117 is a linear voltage regulator IC manufactured by Texas Instruments, classified as a positive adjustable output power management integrated circuit. This device delivers 800mA output current in a SOT-223-4 surface mount package and operates across an input voltage range of up to 15V with adjustable output from 1.25V to 14.6V. The REG1117 is designated as Last Time Buy, indicating end-of-life status. Equivalent and substitute parts are necessary to ensure design continuity, maintain supply chain flexibility, and support long-term product availability for applications requiring positive adjustable linear regulation.

Key Parameters

Parameter	REG1117 Value
Manufacturer	Texas Instruments
Output Configuration	Positive
Output Type	Adjustable
Number of Regulators	1
Voltage - Input (Max)	15V
Voltage - Output (Min/Fixed)	1.25V
Voltage - Output (Max)	14.6V
Voltage Dropout (Max)	1.2V @ 800mA
Current - Output	800mA
Current - Quiescent (Iq)	10 mA
PSRR	62dB (120Hz)
Protection Features	Over Current, Over Temperature
Operating Temperature	-40°C ~ 125°C
Mounting Type	Surface Mount
Package / Case	TO-261-4, TO-261AA
Supplier Device Package	SOT-223-4
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility for the REG1117 is determined by the following critical parameters: positive output configuration, adjustable output type, single regulator topology, maximum input voltage rating of 15V or higher, adjustable output voltage range encompassing 1.25V minimum, output current capability of 800mA or greater, surface mount packaging in SOT-223 or compatible form factor, and operating temperature range that includes or exceeds -40°C to 125°C.

Substitute parts are grouped into two categories:

Category 1: Direct Electrical Equivalents (800mA Output Current) Parts maintaining 800mA output current specification with compatible electrical and thermal characteristics. These include LM1117MPX-ADJ/NOPB, LT1117 series variants (CST#PBF, CST#TRPBF, IST#PBF, IST#TRPBF), and SPX1117M3-L/TR. These parts share identical or superior PSRR performance, matching protection features, and compatible package footprints.

Category 2: Enhanced Performance Substitutes (1A Output Current) Parts exceeding the 800mA specification with 1A output capability, including AZ1117H-ADJTRE1 and AZ1117H-ADJTRG1 from Diodes Incorporated. These provide higher current headroom while maintaining adjustable output voltage range and compatible packaging.

Category 3: Alternative Package Form Factor (1A Output Current, TO-252-5) The BA00BC0WFP-E2 from Rohm Semiconductor offers 1A output current in a TO-252-5 package, suitable for applications where the larger package footprint is acceptable and additional thermal dissipation is beneficial.

Parameter Comparison

Part Number	Manufacturer	Output Current	Input Voltage (Max)	Output Voltage Range	Dropout Voltage	Iq (mA)	PSRR (dB)	Operating Temp	Package	Product Status
REG1117	Texas Instruments	800mA	15V	1.25V - 14.6V	1.2V @ 800mA	10	62 (120Hz)	-40°C ~ 125°C	SOT-223-4	Last Time Buy
LM1117MPX-ADJ/NOPB	Texas Instruments	800mA	15V	1.25V - 13.8V	1.2V @ 800mA	5	75 (120Hz)	0°C ~ 125°C	SOT-223	Active
AZ1117H-ADJTRE1	Diodes Incorporated	1A	15V	1.25V - 13.75V	1.25V @ 1A	10	75 (120Hz)	-40°C ~ 125°C	SOT-223-3	Active
AZ1117H-ADJTRG1	Diodes Incorporated	1A	15V	1.25V - 13.75V	1.25V @ 1A	10	75 (120Hz)	-40°C ~ 125°C	SOT-223-3	Active
BA00BC0WFP-E2	Rohm Semiconductor	1A	16V	1.5V - 12V	Not specified	0.5	55 (120Hz)	-40°C ~ 105°C	TO-252-5	Active
LT1117CST#PBF	Analog Devices Inc.	800mA	15V	1.25V - 13.8V	1.2V @ 800mA	Not specified	75 (120Hz)	0°C ~ 125°C	SOT-223-3	Active
LT1117CST#TRPBF	Analog Devices Inc.	800mA	15V	1.25V - 13.8V	1.2V @ 800mA	Not specified	75 (120Hz)	0°C ~ 125°C	SOT-223-3	Active
LT1117IST#PBF	Analog Devices Inc.	800mA	15V	1.25V - 13.8V	1.3V @ 800mA	Not specified	75 (120Hz)	-40°C ~ 125°C	SOT-223-3	Active
LT1117IST#TRPBF	Analog Devices Inc.	800mA	15V	1.25V - 13.8V	1.3V @ 800mA	Not specified	75 (120Hz)	-40°C ~ 125°C	SOT-223-3	Active
SPX1117M3-L/TR	MaxLinear, Inc.	800mA	20V	1.25V - 15V	1.3V @ 800mA	10	70 (120Hz)	-40°C ~ 125°C	SOT-223-3	Active

Engineering Selection Recommendations

For Direct Replacement (800mA Applications): LM1117MPX-ADJ/NOPB from Texas Instruments is the primary recommended substitute. It maintains 800mA output current, identical input voltage rating, and compatible SOT-223 packaging. The device is in Active product status with high inventory availability (650,655 pcs). Operating temperature range is 0°C to 125°C, which covers the upper portion of the REG1117 range. PSRR performance is improved at 75dB versus 62dB.

LT1117 series variants (CST#PBF, CST#TRPBF, IST#PBF, IST#TRPBF) from Analog Devices Inc. are functionally equivalent with 800mA output current and improved PSRR at 75dB. LT1117IST variants extend operating temperature to -40°C to 125°C, matching the REG1117 specification. All variants are in Active status with substantial inventory.

SPX1117M3-L/TR from MaxLinear, Inc. provides 800mA output current with extended input voltage rating to 20V and output voltage range to 15V. Operating temperature range matches the REG1117 at -40°C to 125°C. This part is suitable for applications requiring higher input voltage tolerance.

For Enhanced Current Capacity (1A Applications): AZ1117H-ADJTRE1 and AZ1117H-ADJTRG1 from Diodes Incorporated both deliver 1A output current in SOT-223-3 packaging with operating temperature range of -40°C to 125°C. These parts are suitable for applications where current headroom beyond 800mA is required. Both variants are in Active status with good inventory levels.

For Alternative Packaging (Thermal Considerations): BA00BC0WFP-E2 from Rohm Semiconductor offers 1A output current in TO-252-5 packaging, providing superior thermal dissipation compared to SOT-223 form factors. This part is appropriate for applications with elevated ambient temperatures or higher power dissipation requirements. Operating temperature range is -40°C to 105°C. The device includes Enable control feature not present in the REG1117.

All recommended substitutes comply with RoHS3 and REACH requirements, matching the REG1117 compliance profile.

Frequently Asked Questions (FAQ)

Q: Can LM1117MPX-ADJ/NOPB directly replace REG1117 in all applications? A: LM1117MPX-ADJ/NOPB is electrically compatible for applications operating within 0°C to 125°C. Applications requiring operation below 0°C must use LT1117IST variants or SPX1117M3-L/TR, which support -40°C to 125°C. Pin configuration and SOT-223 packaging are compatible.

Q: What is the difference between LT1117CST and LT1117IST variants? A: The primary difference is operating temperature range. LT1117CST operates 0°C to 125°C, while LT1117IST operates -40°C to 125°C. Both deliver 800mA output current with identical electrical specifications. Selection depends on application temperature requirements.

Q: Are AZ1117H parts suitable for 800mA applications? A: Yes. AZ1117H parts are rated for 1A output current, which exceeds the 800mA requirement. They are backward compatible with 800mA designs and provide additional current margin. Adjustable output voltage range (1.25V to 13.75V) is compatible with REG1117 applications.

Q: What is the advantage of BA00BC0WFP-E2 over SOT-223 packages? A: BA00BC0WFP-E2 uses TO-252-5 packaging, which provides larger copper area for improved thermal dissipation. This is beneficial for applications with high power dissipation or elevated ambient temperatures. The trade-off is larger PCB footprint. Output current is rated at 1A versus 800mA.

Q: Can I use SPX1117M3-L/TR with input voltages above 15V? A: Yes. SPX1117M3-L/TR is rated for maximum input voltage of 20V, compared to 15V for REG1117. This allows operation with higher input voltage sources while maintaining adjustable output regulation. All other electrical characteristics remain compatible.

Q: Are all substitute parts RoHS3 compliant? A: Yes. All recommended substitute parts listed are RoHS3 compliant and REACH unaffected, matching the REG1117 compliance status.

Q: What packaging options are available for substitutes? A: Most substitutes use SOT-223-3 or SOT-223-4 packaging, maintaining footprint compatibility with REG1117. BA00BC0WFP-E2 uses TO-252-5 packaging for enhanced thermal performance. Packaging selection depends on PCB layout constraints and thermal requirements.

Q: Which substitute has the lowest quiescent current? A: BA00BC0WFP-E2 has the lowest quiescent current at 0.5mA, compared to 10mA for REG1117. LM1117MPX-ADJ/NOPB offers reduced quiescent current at 5mA. Lower quiescent current reduces standby power consumption in battery-powered applications.

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