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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Special Purpose Regulators

STMicroelectronics L4943

Name: L4943
Brand: STMicroelectronics
SKU: L4943
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L4943

Manufacturer:: STMicroelectronics

Category:: Special Purpose Regulators

Package:: Multiwatt-15 (Vertical, Bent and Staggered Leads)

Datasheet:: L4943.pdf

Description:: IC REG CONV CAR 3OUT 15MULTIWATT

Quantity:: RFQ Add To RFQ list

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Inventory:1,995

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Product details

Overview

L4943 from STMicroelectronics is a multifunction voltage regulator IC for automotive car radio systems, integrating three independently programmable linear regulators (5V/0.5A standby, 3–11V/0.5A adj1, 3–11V/0.5A adj2) and a 0.4A high-side driver with load-dump protection and thermal shutdown. It supports data retention during fault via STCAP-supplied reserve energy and operates across –40°C to +85°C.

For engineers reviewing the L4943 datasheet, L4943 pinout, L4943 application, or L4943 equivalent, key selection criteria include triple-output voltage programmability, independent EN1/EN2 standby control, integrated high-side driver dropout <0.6V at 400mA, load-dump protection, and Multiwatt-15 package thermal resistance of 2°C/W.

Technical Context

The L4943 implements three separate linear regulator channels with adjustable output voltages set by external resistor dividers (1+R1/R2 = 2.4–5.6 for VMEM; up to 8.8 for VADJ1/VADJ2), each delivering up to 500mA with dropout as low as 0.36V. Standby outputs remain active during thermal shutdown or faults using energy stored on the STCAP capacitor.

The integrated high-side driver features enable-controlled switching (EN2H threshold 1.3V), 400mA continuous current capability, <0.6V dropout at 9–16V supply, and built-in load-dump transient suppression. All regulators share a common VS input (–0.6V to 30V DC, 50V transient) and dual ground pins (P-GND/S-GND) for noise isolation.

Key Specifications

Parameter	Value and Actual Design Meaning
VMEM Output	3–7V @ 500mA; factory-trimmed to 5V ±5% with STCAP-supported data-retention hold-up
VADJ1/VADJ2	3–11V @ 500mA each; independently programmable via external resistors; SVR ≥45dB (0.1–10kHz)
HSD Current	400mA continuous; 0.45–0.8A short-circuit limit; EN2H ON threshold = 1.3V
Dropout Voltage	0.36V (VMEM, 200mA); 0.45V (VADJ1/VADJ2, 200mA); 0.2V (HSD, 400mA)
Thermal Protection	Active thermal shutdown with latch-off; junction-to-case R_th = 2°C/W (Multiwatt-15)
Supply Range	VS = –0.6V to 30V DC; withstands 50V/50ms transients per ISO 7637-2
Operating Temp	–40°C to +85°C ambient; qualified for automotive infotainment power rails

Pinout & Package

Package: Multiwatt-15 (vertical, tab-connected to Pin 8, P-GND), with thermal pad for 2°C/W junction-to-case dissipation. Dimensions per STMicroelectronics outline D97AU672B (L = 22.2mm, H2 = 20.2mm, tab width = 17.75mm).

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 13, 14, 15	Regulator outputs, enables, supplies, grounds	VMEM_feed (1), VADJ1_feed (2), VADJ2_feed (3), STCAP (4), EN1 (5), EN2 (6), VS (7), P-GND (9), S-GND (10), FILTER CAP (11), HSD (13), VADJ2 (14), VADJ1 (15)
8	Thermal tab / Power ground	Internally connected to Pin 8; must be soldered to PCB copper pour for thermal management
12	VMEM output	Main 5V standby rail; remains active during fault conditions if STCAP charged

Key Features

Feature	Design Value
Triple independent regulators	Three fully decoupled LDOs: one fixed 5V standby (VMEM), two adjustable (VADJ1/VADJ2) with separate EN controls
STCAP-assisted fault hold-up	STCAP pin sustains µP data-save operation during thermal shutdown or overcurrent events using external capacitor energy
Integrated high-side driver	0.4A rated switch with <0.6V dropout, load-dump clamping, and EN2H logic-level interface (1.3V threshold)
Dual ground separation	P-GND (pins 9 & 8) and S-GND (pin 10) isolate power and signal return paths to reduce noise coupling
Automotive transient robustness	Withstands 50V/50ms load-dump pulses per ISO 7637-2 without external TVS or clamp diodes

Applications

Car Radio Power Management

Infotainment System Core Supply

Use Scenario: Primary power distribution unit in OEM car radios, supplying µP core, display backlight, and audio DAC rails.

IC Role / Device Role / Timing Role: Triple-output LDO regulator + HSD for speaker protection switching.

Use Value: Eliminates need for discrete 5V standby LDO + two adjustable regulators + external high-side switch, reducing BOM count by ≥4 components.

Use Scenario: Central power controller in head-unit designs requiring isolated 5V standby, 8V audio bias, and 10V display supply.

IC Role / Device Role / Timing Role: Programmable multi-rail voltage source with fault-tolerant hold-up for system state preservation.

Use Value: STCAP-enabled 5V rail maintains µP operation >100ms after main supply loss, enabling safe firmware save before shutdown.

Automotive Telematics Module

Aftermarket Display Controller

Use Scenario: Power subsystem for LTE/GPS modules where low quiescent current and transient immunity are critical.

IC Role / Device Role / Timing Role: High-reliability regulator with integrated load-dump protection for CAN-connected modules.

Use Value: Built-in 50V transient tolerance eliminates need for external TVS diodes on VS line, saving board space and cost.

Use Scenario: Power management in aftermarket LCD dash displays requiring multiple regulated rails and backlight control.

IC Role / Device Role / Timing Role: Adjustable regulator pair (VADJ1/VADJ2) + HSD for LED string switching and brightness control.

Use Value: HSD enables direct PWM dimming of 12V LED strings without external MOSFET, simplifying layout and improving EMI performance.

Equivalent & Alternatives

The following parts are listed as comparable options for similar multifunction automotive regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TLE4275G	Single 5V/400mA LDO; no adjustable outputs or HSD; lower I_q (70µA vs 350µA)	Only suitable for basic 5V-only systems; lacks triple-rail flexibility and driver integration	Select when only 5V regulation is needed and board space is constrained
L9752	Dual 5V/500mA LDOs + 0.5A HSD; no VMEM/STCAP hold-up; no adjustable outputs	Supports dual-rail but not data-retention standby; missing STCAP functionality for µP save	Select for dual-regulator + HSD needs where fault hold-up is not required

Compared with TLE4275G and L9752, the L4943 uniquely combines triple programmable outputs, STCAP-based data retention, and integrated HSD-making it the only option for automotive infotainment systems requiring simultaneous 5V standby, dual adjustable rails, and speaker protection switching in one package.

Availability

L4943 is available at Aetrix Electronics and suitable for car radio power management, infotainment system core supply, and automotive telematics module design requiring stable component supply across extended temperature and transient-voltage environments.

Supply support for L4943 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, designing and manufacturing analog, microcontroller, power, and automotive ICs for industrial, automotive, and consumer markets.

The L4943 belongs to ST's automotive power management product line, engineered specifically for car radio and infotainment systems needing integrated multi-rail regulation, fault-tolerant standby, and high-side load switching in harsh electrical environments.

FAQ

What is the function of the STCAP pin on the L4943?

The STCAP pin connects to an external capacitor that stores energy to maintain the 5V VMEM standby output during fault conditions-including thermal shutdown, overcurrent, or main supply loss. This allows the connected microprocessor to execute a controlled data-save routine before complete power-down, supporting automotive safety and reliability requirements.

Can the L4943's adjustable regulators be set below 3V?

No-the L4943's VADJ1 and VADJ2 outputs are specified for 3V to 11V operation only, with minimum output voltage limited by internal reference and error amplifier architecture. Attempting sub-3V configuration results in regulation failure or uncontrolled dropout behavior, as confirmed by electrical characteristics tables showing 2.85V minimum under nominal conditions.

How does the L4943 handle load-dump transients?

The L4943 withstands 50V/50ms load-dump transients per ISO 7637-2 on its VS pin without external protection, using internal clamp circuitry and robust junction design. Its absolute maximum VS rating is 50V, and thermal shutdown activates only if sustained dissipation exceeds 33W-ensuring continued operation during typical automotive transients.

Is the L4943 pin-compatible with newer ST automotive regulators like the L9752?

No-the L4943 uses a Multiwatt-15 package with unique pin assignments (e.g., STCAP at Pin 4, VMEM at Pin 12, tab tied to Pin 8), while the L9752 uses PowerSSO-36 and assigns functions differently (no STCAP, different EN logic thresholds, no VMEM feed). Direct replacement requires PCB redesign and firmware adaptation.

L4943 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: Multiwatt-15 (Vertical, Bent and Staggered Leads)

Packaging:: Tube

Product Status:: Obsolete

Applications:: Converter, Car Audio System

Voltage - Input:: 11V ~ 18V

Number of Outputs:: 3

Voltage - Output:: 3V ~ 11V

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: 15-Multiwatt

L4943 FAQ

1.How can I place an order for L4943 through Aetrix?

Please submit a Request for Quotation (RFQ) for L4943 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 L4943 reliable?

The price and inventory of L4943 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L4943 is usually 5 days.

3.What payment methods are accepted for L4943?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L4943 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L4943?

L4943 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L4943 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 L4943?

For technical support, including L4943 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L4943 requirements.

6.How does Aetrix verify that L4943 is sourced from the original manufacturer or authorized distributors?

All L4943 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 L4943 meets industry standards.

7.What is the process for return or replacement of L4943?

All L4943 units undergo pre-shipment inspection (PSI). If there is an issue with L4943, 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 L4943 part is unused and in its original packaging.

Return procedure for L4943:

1.Submit a request within 90 days.

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

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