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

STMicroelectronics L78L24ACD-TR

Name: L78L24ACD-TR
Brand: STMicroelectronics
SKU: L78L24ACD-TR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L78L24ACD-TR

Manufacturer:: STMicroelectronics

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

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: L78L24ACD-TR.pdf

Description:: IC REG LINEAR 24V 100MA 8SO

Quantity:: RFQ Add To RFQ list

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Inventory:1,049

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Product details

Overview

L78L24ACD-TR from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 24 V output at up to 100 mA, featuring internal current limiting, thermal overload protection, and short-circuit protection. It requires no external components and is rated for operation from −40 °C to +125 °C, commonly used in local on-card regulation for industrial control I/O modules and sensor signal conditioning circuits.

For engineers reviewing the L78L24ACD-TR datasheet, L78L24ACD-TR pinout, L78L24ACD-TR application, or L78L24ACD-TR equivalent, key selection criteria include output voltage tolerance (±4%), dropout voltage (1.7 V), quiescent current (6.5 mA typ.), and SO-8 package thermal performance with integrated die-attach flag for enhanced heat dissipation.

Technical Context

The L78L24ACD-TR implements a monolithic silicon-based series pass regulator architecture with built-in foldback current limiting and thermal shutdown circuitry. Its internal reference and error amplifier maintain output regulation across input voltages from 27 V to 38 V and load currents from 1 mA to 100 mA.

It operates without external capacitors for stability but specifies 0.33 µF input and 0.1 µF output ceramic capacitors for optimal transient response and noise suppression. The SO-8 package integrates pins 2, 3, 6, and 7 to the die attach flag, reducing junction-to-case thermal resistance to 20 °C/W.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	24 V ±4% (23–25 V) at TJ = 25 °C; ensures stable supply for 24 V logic interfaces and analog front-ends
Output Current	Up to 100 mA continuous; sufficient for powering microcontroller peripherals, op-amps, and low-power sensors
Dropout Voltage	1.7 V typical at 40 mA; enables regulation from 25.7 V minimum input when outputting 24 V
Quiescent Current	6.5 mA typical at 25 °C; low static consumption supports battery-backed or energy-sensitive systems
Supply Rejection	31–37 dB at 120 Hz (VI = 29–33 V); attenuates ripple from unregulated DC-DC stages or rectified AC supplies
Noise Voltage	200 µV RMS (10 Hz–100 kHz); suitable for noise-sensitive analog signal chains without additional filtering
Thermal Resistance	R_thJC = 20 °C/W (SO-8); enables 1.2 W power dissipation with ≤25 °C case-to-ambient gradient under PCB copper heatsinking

Pinout & Package

The L78L24ACD-TR is housed in an SO-8 surface-mount package with exposed die attach flag connected to pins 2, 3, 6, and 7 for thermal enhancement. Pin 1 is V_OUT, pin 4 is GND, and pin 5 is V_IN.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1	V_OUT	Regulated 24 V output; connects directly to load and output capacitor (0.1 µF ceramic)
Pin 4	GND	Ground reference for both input and output circuits; must be low-impedance return path
Pin 5	V_IN	Unregulated input (27–38 V); requires 0.33 µF ceramic capacitor placed near pin
Pins 2, 3, 6, 7	Thermal Flag / GND	Internally bonded to die attach flag; must be soldered to ≥6 cm² PCB copper pour for thermal management

Key Features

Feature	Design Value
Fixed Output Voltage	24 V with ±4% tolerance over temperature and load - eliminates need for external feedback resistors
Integrated Protection	Thermal shutdown and short-circuit foldback limit fault energy and prevent device destruction during overloads
No External Components	Stable operation with only input/output bypass capacitors - reduces BOM count and board space vs. adjustable regulators
Low Noise Performance	200 µV RMS output noise (10 Hz–100 kHz) - avoids post-regulation filtering in precision analog subsystems
Enhanced Thermal SO-8	Die attach flag tied to four pins lowers R_thJA to 55 °C/W with 6 cm² copper - enables higher ambient operation than TO-92

Applications

Industrial PLC I/O Modules

Automotive Body Control Units

Use Scenario: Powering isolated digital input buffers and relay driver circuits in DIN-rail mounted programmable logic controllers.

IC Role / Device Role: Local 24 V regulation for field-side interface circuitry, decoupling noisy 24 V bus from sensitive logic.

Use Value: Maintains 24 V compliance under 100 mA load steps while rejecting >30 dB of conducted bus ripple.

Use Scenario: Supplying microcontroller peripherals and CAN transceiver bias in non-safety-critical body electronics.

IC Role / Device Role: Secondary regulation stage after main automotive DC-DC converter, providing clean 24 V for LIN/CAN subsystems.

Use Value: Operates across −40 °C to +125 °C junction range and withstands load dump transients via internal protection.

Medical Sensor Signal Conditioning

Test & Measurement Equipment

Use Scenario: Biasing precision op-amps and ADC drivers in portable patient monitoring devices with isolated analog front-ends.

IC Role / Device Role: Low-noise 24 V rail generator for instrumentation amplifiers requiring high PSRR and minimal output ripple.

Use Value: 200 µV RMS noise and 37 dB SVR enable <1 LSB noise contribution in 16-bit medical ADC designs.

Use Scenario: Providing stable excitation voltage for strain gauge bridges and RTD measurement circuits in benchtop analyzers.

IC Role / Device Role: Fixed-voltage source for ratiometric sensor excitation where absolute accuracy is secondary to stability and repeatability.

Use Value: ±4% output tolerance and <100 mV load regulation ensure consistent bridge bias across varying sensor impedances.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM78L24ACM/NOPB	Same 24 V ±5% output, but TO-92 package (R_thJA = 200 °C/W); higher quiescent current (7.5 mA)	Limited to ≤30 mA continuous in still air; unsuitable for high-density or thermally constrained PCBs	Select only if through-hole assembly is required and thermal budget allows derating
TL78L24ACDR	24 V ±5%, SO-8 package, but lower SVR (28 dB @ 120 Hz) and higher noise (350 µV)	Requires additional LC filtering for noise-sensitive analog loads; less robust against input ripple	Prefer only in cost-sensitive, non-precision applications where thermal and noise specs are relaxed

Compared with LM78L24ACM/NOPB and TL78L24ACDR, the L78L24ACD-TR offers superior thermal performance in SO-8, tighter output tolerance (±4% vs. ±5%), and lower noise-making it optimal for compact, high-reliability industrial and test equipment designs.

Availability

L78L24ACD-TR is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, and test & measurement equipment requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for L78L24ACD-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 sensing solutions for industrial, automotive, and consumer markets.

The L78L series was developed as a modern, thermally enhanced replacement for legacy 78Lxx regulators, targeting space-constrained and thermally demanding applications where reliability and ease of use are critical.

FAQ

What is the minimum input voltage required for the L78L24ACD-TR to regulate at full load?

The L78L24ACD-TR requires a minimum input voltage of 25.7 V to maintain 24 V output at 100 mA load, based on its 1.7 V typical dropout voltage. At light loads (<10 mA), regulation is sustained down to ~24.5 V, but design margin should include worst-case dropout (up to 2.0 V) and input ripple.

Can the L78L24ACD-TR be used in parallel to increase output current?

No-parallel operation is not recommended due to mismatch in output voltage tolerances (±4%) and lack of current-sharing circuitry. Uneven current distribution may cause thermal runaway. For >100 mA, use a single higher-current regulator or add an external pass transistor with proper biasing.

Is a heat sink required for the SO-8 package in typical applications?

A dedicated heat sink is not required, but the die attach flag (pins 2/3/6/7) must be soldered to ≥6 cm² of 2-oz copper on the PCB to achieve the specified R_thJA of 55 °C/W. Without this copper area, junction temperature rise exceeds safe limits above ~50 mA at 70 °C ambient.

Does the L78L24ACD-TR require input and output capacitors, and what values are recommended?

Yes-STMicroelectronics specifies a 0.33 µF ceramic capacitor at the input (close to pin 5) and a 0.1 µF ceramic capacitor at the output (close to pin 1) for stability and transient response. Larger bulk capacitance may be added externally, but these minimum values are mandatory for guaranteed operation.

L78L24ACD-TR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 40V

Voltage - Output (Min/Fixed):: 24V

Voltage - Output (Max):: -

Voltage Dropout (Max):: -

Current - Output:: 100mA

Current - Quiescent (Iq):: 6 mA

Current - Supply (Max):: 6.5 mA

PSRR:: 37dB (120Hz)

Control Features:: -

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

Operating Temperature:: 0°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

L78L24ACD-TR FAQ

1.How can I place an order for L78L24ACD-TR through Aetrix?

Please submit a Request for Quotation (RFQ) for L78L24ACD-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 L78L24ACD-TR reliable?

The price and inventory of L78L24ACD-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L78L24ACD-TR is usually 5 days.

3.What payment methods are accepted for L78L24ACD-TR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L78L24ACD-TR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L78L24ACD-TR?

L78L24ACD-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L78L24ACD-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 L78L24ACD-TR?

For technical support, including L78L24ACD-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L78L24ACD-TR requirements.

6.How does Aetrix verify that L78L24ACD-TR is sourced from the original manufacturer or authorized distributors?

All L78L24ACD-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 L78L24ACD-TR meets industry standards.

7.What is the process for return or replacement of L78L24ACD-TR?

All L78L24ACD-TR units undergo pre-shipment inspection (PSI). If there is an issue with L78L24ACD-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 L78L24ACD-TR part is unused and in its original packaging.

Return procedure for L78L24ACD-TR:

1.Submit a request within 90 days.

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

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