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LP3990MFX-3.3
Texas Instruments
IC REG LINEAR 3.3V 150MA SOT23-5
22961 Pcs New Original In Stock
Linear Voltage Regulator IC Positive Fixed 1 Output 150mA SOT-23-5
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5.0 / 5.0
- (181 Ratings)
LP3990MFX-3.3
Product Overview
1344467
DiGi Electronics Part Number
LP3990MFX-3.3-DGManufacturer
Texas Instruments
LP3990MFX-3.3
Description
IC REG LINEAR 3.3V 150MA SOT23-5Inventory
22961 Pcs New Original In Stock
Linear Voltage Regulator IC Positive Fixed 1 Output 150mA SOT-23-5
Quantity
Minimum 1
Minimum 1
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LP3990MFX-3.3 Technical Specifications
Category
Power Management (PMIC), Voltage Regulators - Linear, Low Drop Out (LDO) Regulators
Packaging
-
Series
-
Product Status
Obsolete
Output Configuration
Positive
Output Type
Fixed
Number of Regulators
1
Voltage - Input (Max)
6V
Voltage - Output (Min/Fixed)
3.3V
Voltage - Output (Max)
-
Voltage Dropout (Max)
0.2V @ 150mA
Current - Output
150mA
Current - Quiescent (Iq)
80 µA
Current - Supply (Max)
120 µA
PSRR
55dB ~ 35dB (1kHz ~ 10kHz)
Control Features
Enable
Protection Features
Over Temperature, Short Circuit
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
SC-74A, SOT-753
Supplier Device Package
SOT-23-5
Base Product Number
LP3990
Datasheet & Documents
HTML Datasheet
LP3990MFX-3.3-DG
Environmental & Export Classification
RoHS Status
RoHS non-compliant
Moisture Sensitivity Level (MSL)
1 (Unlimited)
REACH Status
REACH Unaffected
ECCN
EAR99
HTSUS
8542.39.0001
Additional Information
Standard Package
3,000
Alternative Parts
View DetailsPART NUMBER
MANUFACTURER
QUANTITY AVAILABLE
DiGi PART NUMBER
UNIT PRICE
SUBSTITUTE TYPE
Reviews
5.0/5.0-(Show up to 5 Ratings)
Dec 02, 2025
每次購買後，包裝都非常堅固，保護商品完好無損。
Dec 02, 2025
Service express et équipe après-vente toujours disponible et efficace. Je suis très content de leur professionnalisme.
Dec 02, 2025
長期的に見て、価格と商品の一貫性が非常に優れていると感じます。
Dec 02, 2025
Receiving shipments right on schedule and with high-quality parts helps me maintain high service standards.
Dec 02, 2025
Customer feedback indicates high satisfaction with their post-purchase support.
Dec 02, 2025
Their prompt response to after-sales inquiries truly showcases their commitment to customer satisfaction.
Dec 02, 2025
I love how DiGi Electronics offers great prices on quality items. It’s a win-win for me.
Dec 02, 2025
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Dec 02, 2025
Customer service was friendly and responded instantly to my questions.
Dec 02, 2025
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Frequently Asked Questions (FAQ)
Can the LP3990MFX-3.3 be used in battery-powered designs where low quiescent current is critical, and how does its 80 µA Iq impact system runtime in always-on applications?
Yes, the LP3990MFX-3.3 with 80 µA quiescent current is suitable for battery-powered systems requiring moderate efficiency in low-power modes. However, design-in engineers should note that while 80 µA is reasonable for a linear regulator with enable, newer alternatives like the MIC5318-3.3YD5-TR (45 µA Iq) offer lower consumption for ultra-low-power designs. To maximize runtime, ensure the enable pin is actively driven low when not in use—since the LP3990MFX-3.3 does not fully power down by default—and consider duty-cycling the load if feasible. Thermal performance should also be validated under maximum load and ambient conditions due to its limited PSRR above 10kHz.
What are the key risks of selecting the LP3990MFX-3.3 given that it's marked as obsolete by Texas Instruments?
Using the LP3990MFX-3.3 in new designs carries significant supply chain risk due to its obsolete status, increasing the likelihood of long-term availability issues. Engineers should evaluate direct replacement candidates such as the AP7335-33WG-7 or MIC5318-3.3YD5-TR early in the design cycle. If proceeding, secure extended inventory with MSL1 moisture protection for long-term storage and verify second-source options with compatible SOT-23-5 footprints. Include a footprint-compatible alternative in the PCB layout (e.g., 0R resistor option) to mitigate end-of-life integration disruptions.
How does the LP3990MFX-3.3's dropout voltage of 0.2V at 150mA affect performance in a 3.3V rail supplied by a single Li-ion cell?
The LP3990MFX-3.3’s 0.2V dropout enables usable operation down to ~3.5V input, which limits effective regulation as a single-cell Li-ion discharges below 3.6V. At 3.4V input, the regulator may drop out under full 150mA load, risking brownouts. Designers must either derate output current as battery voltage drops or confirm minimum operating voltage with margin: for example, limiting max load to 100mA extends usable life slightly due to lower dropout at lighter loads. For deeper discharge use, consider alternatives like the S-1315C33-M5T1U3 with lower dropout (~0.1V at 150mA) for better efficiency near end-of-discharge.
Is the LP3990MFX-3.3 suitable for noise-sensitive analog circuits given its PSRR of 55dB at 1kHz decaying to 35dB at 10kHz?
The LP3990MFX-3.3 provides moderate PSRR (55dB @ 1kHz, 35dB @ 10kHz), making it acceptable for general-purpose analog rails but risky for high-precision signal chains (e.g., ADCs, RF modules). Engineers must add external filtering—such as a ferrite bead and 1–10µF low-ESR capacitor post-regulator—to reduce switching noise from upstream DC-DC converters. Avoid using the LP3990MFX-3.3 as a post-regulator after noisy buck converters without additional LC filtering. For improved noise performance, compare with the MIC5318-3.3YD5-TR (70dB PSRR @ 1kHz) in similar applications.
What are the thermal design implications when replacing an AP7335-33WG-7 with the LP3990MFX-3.3 in a high-ambient-temperature environment?
Replacing the AP7335-33WG-7 with the LP3990MFX-3.3 in high-temperature environments requires careful thermal evaluation due to differences in package thermal resistance and power dissipation. The LP3990MFX-3.3 in SOT-23-5 has higher junction-to-ambient (θJA ~200°C/W) than some modern equivalents, limiting its ability to dissipate heat. For example, at 500mV dropout and 150mA load, it dissipates 75mW, causing ~15°C rise—acceptable below 70°C ambient, but risky near 85°C max rating. Ensure adequate PCB copper pour for thermal dissipation and derate current accordingly; consider AP7335-33WG-7’s better thermal performance if long-term reliability in hot environments is a priority.
Quality Assurance (QC)
DiGi ensures the quality and authenticity of every electronic component through professional inspections and batch sampling, guaranteeing reliable sourcing, stable performance, and compliance with technical specifications, helping customers reduce supply chain risks and confidently use components in production.
LP3990MFX-3.3 CAD Models
Texas Instruments LP3990MFX-3.3 PCB symbols & footprints
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