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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

STMicroelectronics L78L15ACZ-TR

Name: L78L15ACZ-TR
Brand: STMicroelectronics
SKU: L78L15ACZ-TR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L78L15ACZ-TR

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Datasheet:: L78L15ACZ-TR.pdf

Description:: IC REG LINEAR 15V 100MA TO92-3

Quantity:: RFQ Add To RFQ list

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Inventory:3,129

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Product details

Overview

L78L15ACZ-TR from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 15 V output at up to 100 mA, with ±4% output voltage tolerance (A grade), thermal overload protection, short-circuit protection, and 1.7 V dropout voltage. It operates across -40 °C to 125 °C junction temperature and requires no external components for basic regulation-commonly used in local on-card power conditioning for microcontroller peripherals and sensor interfaces.

For engineers reviewing the L78L15ACZ-TR datasheet, L78L15ACZ-TR pinout, L78L15ACZ-TR application, or L78L15ACZ-TR equivalent, key selection criteria include its TO-92 package compatibility, guaranteed 14.4–15.6 V output at 25 °C, 90 µV RMS output noise (10 Hz–100 kHz), 34–39 dB supply voltage rejection at 120 Hz, and quiescent current of 6.5 mA at 25 °C.

Technical Context

The L78L15ACZ-TR implements a monolithic silicon-based linear regulation architecture with internal current limiting and thermal shutdown circuitry. Its design eliminates need for external compensation or pass transistors, enabling direct replacement of Zener diode/resistor networks while reducing quiescent current and output noise.

It maintains stable 15 V output under load currents from 1 mA to 100 mA and input voltages from 17.5 V to 30 V, with line regulation of ≤250 mV and load regulation of ≤75 mV over specified conditions-making it suitable for low-noise, space-constrained embedded power rails where thermal management is limited.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	15 V nominal, 14.4–15.6 V at 25 °C (±4% A-grade tolerance)
Max Output Current	100 mA continuous-supports small-signal ICs, sensors, and logic without external pass devices
Dropout Voltage	1.7 V typical-requires minimum 16.7 V input for regulated 15 V output at full load
Quiescent Current	6.5 mA at 25 °C-enables predictable bias consumption in battery-backed or low-power systems
Output Noise	90 µV RMS (10 Hz–100 kHz)-low enough for analog sensor front-ends and precision references
SVR	34–39 dB at 120 Hz-rejects ripple from rectified AC supplies or switching pre-regulators
Operating Temp	-40 °C to +125 °C junction-qualified for industrial and automotive under-hood environments

Pinout & Package

Supplied in TO-92 package (Z suffix), with 3 leads: Pin 1 = VOUT, Pin 2 = GND, Pin 3 = VIN. The TO-92 housing provides low-cost through-hole mounting and moderate thermal dissipation (R_thJA = 200 °C/W, R_thJC = 15 °C/W) when used with minimal PCB copper area.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1	VOUT	Regulated +15 V output terminal-connects directly to load and local bypass capacitor (0.1 µF typical)
Pin 2	GND	Reference ground return-must be low-impedance path shared with input capacitor and load ground
Pin 3	VIN	Unregulated DC input (17.5–30 V)-requires 0.33 µF input capacitor close to pin for stability

Key Features

Feature	Design Value
No external components required	Internal compensation and protection eliminate need for external capacitors beyond mandatory input/output bypassing
Thermal overload protection	Automatic shutdown below 165 °C junction temperature-prevents permanent damage during sustained overload
Short-circuit protection	Current-limited output (≈150 mA typical) prevents destruction during output-to-ground faults
Low quiescent current	6.5 mA at 25 °C-reduces standby power loss in always-on subsystems
Fixed output voltage	15 V trimmed at wafer level-avoids resistor network errors and long-term drift of discrete solutions

Applications

Industrial Sensor Interface

Microcontroller Local Regulation

Use Scenario: Powering analog-output temperature/humidity sensors in PLC I/O modules.

IC Role / Device Role / Timing Role: Provides clean, stable 15 V bias for sensor excitation and op-amp signal conditioning stages.

Use Value: 90 µV output noise and 34–39 dB SVR minimize measurement error from supply ripple or EMI coupling.

Use Scenario: Supplying 15 V to ADC reference buffers and CAN transceiver bias in edge-node controllers.

IC Role / Device Role / Timing Role: Acts as dedicated local regulator isolating sensitive analog/digital domains from noisy main 24 V rail.

Use Value: ±4% tolerance and 75 mV load regulation ensure consistent reference accuracy across 1–100 mA load variation.

Legacy Equipment Retrofit

Low-Power Analog Front-End

Use Scenario: Replacing aging Zener/resistor regulators in field-installed instrumentation.

IC Role / Device Role / Timing Role: Direct drop-in substitute offering lower quiescent current and tighter voltage tolerance.

Use Value: 6.5 mA quiescent current vs. ~10–15 mA for Zener solutions reduces thermal load and improves reliability.

Use Scenario: Biasing precision op-amps and voltage references in portable test equipment.

IC Role / Device Role / Timing Role: Delivers low-noise 15 V rail decoupled from switching power supply outputs.

Use Value: 1.7 V dropout enables operation from compact 16.7 V intermediate supplies, minimizing heat generation.

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-voltage linear regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM78L15ACZ/NOPB	±5% output tolerance, higher 8 mA quiescent current, 100 µV output noise	Slightly looser regulation and higher noise-acceptable where cost sensitivity outweighs precision needs	Select if legacy TI design compatibility or dual-sourcing is required; verify 15.0 V ±5% meets system margin
MC78L15ACP	TO-92 package, ±5% tolerance, 120 µV output noise, no guaranteed 125 °C operation	Not qualified for extended temperature range-limited to commercial/industrial ambient use	Choose only for non-automotive, non-extended-temp applications where lower cost is critical

Compared with LM78L15ACZ/NOPB and MC78L15ACP, the L78L15ACZ-TR offers tighter ±4% output tolerance, lower 90 µV noise, and guaranteed operation to +125 °C junction-making it preferred for high-reliability industrial sensing and automotive body electronics where thermal robustness and voltage accuracy are critical.

Availability

L78L15ACZ-TR is available at Aetrix Electronics and suitable for industrial sensor interfaces, microcontroller local regulation, legacy equipment retrofit, and low-power analog front-end designs requiring stable component supply and long-term manufacturability.

Supply support for L78L15ACZ-TR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The L78L series belongs to ST's legacy linear regulator product line, engineered for cost-sensitive, space-constrained applications requiring fixed-output voltage regulation without external components-targeting on-card power distribution and noise-sensitive analog subsystems.

FAQ

What is the maximum allowable input voltage for L78L15ACZ-TR?

The absolute maximum DC input voltage is 35 V for 15 V output variants per STMicroelectronics datasheet DocID2145 Rev 25. Operation above 30 V is not recommended for continuous use due to increased thermal stress and reduced reliability margin. Derating is advised above 25 V input in enclosed or high-ambient-temperature environments.

Can L78L15ACZ-TR be used in surface-mount designs?

No-L78L15ACZ-TR uses a TO-92 through-hole package (Z suffix). ST offers SOT-89 (L78L15ACD-TR) and SO-8 (L78L15ACD2-TR) variants for surface-mount assembly, but the Z-TR variant is exclusively leaded and requires through-hole PCB mounting and wave or hand soldering.

Does L78L15ACZ-TR require input and output capacitors?

Yes-ST specifies a minimum 0.33 µF ceramic or tantalum input capacitor and 0.1 µF ceramic output capacitor, placed as close as possible to the respective pins. Omitting either capacitor risks instability, oscillation, or degraded transient response, especially under dynamic load conditions.

How does thermal performance compare between TO-92 and SOT-89 packages for this regulator?

In TO-92 (L78L15ACZ-TR), R_thJA is 200 °C/W (no heatsink); in SOT-89 (L78L15ACD-TR), it is 55 °C/W with 6 cm² copper pour. At 100 mA and 30 V input, TO-92 junction temperature rise exceeds 100 °C-limiting safe continuous operation. SOT-89 supports full 100 mA output in most PCB layouts without forced air.

L78L15ACZ-TR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 35V

Voltage - Output (Min/Fixed):: 15V

Voltage - Output (Max):: -

Voltage Dropout (Max):: -

Current - Output:: 100mA

Current - Quiescent (Iq):: 6 mA

Current - Supply (Max):: 6.5 mA

PSRR:: 39dB (120Hz)

Control Features:: -

Protection Features:: Over Current, Over Temperature, Short Circuit

Operating Temperature:: 0°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

L78L15ACZ-TR FAQ

1.How can I place an order for L78L15ACZ-TR through Aetrix?

Please submit a Request for Quotation (RFQ) for L78L15ACZ-TR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for L78L15ACZ-TR reliable?

The price and inventory of L78L15ACZ-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L78L15ACZ-TR is usually 5 days.

3.What payment methods are accepted for L78L15ACZ-TR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L78L15ACZ-TR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L78L15ACZ-TR?

L78L15ACZ-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L78L15ACZ-TR order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for L78L15ACZ-TR?

For technical support, including L78L15ACZ-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L78L15ACZ-TR requirements.

6.How does Aetrix verify that L78L15ACZ-TR is sourced from the original manufacturer or authorized distributors?

All L78L15ACZ-TR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that L78L15ACZ-TR meets industry standards.

7.What is the process for return or replacement of L78L15ACZ-TR?

All L78L15ACZ-TR units undergo pre-shipment inspection (PSI). If there is an issue with L78L15ACZ-TR, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The L78L15ACZ-TR part is unused and in its original packaging.

Return procedure for L78L15ACZ-TR:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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