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

STMicroelectronics L5955

Name: L5955
Brand: STMicroelectronics
SKU: L5955
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L5955

Manufacturer:: STMicroelectronics

Category:: Special Purpose Regulators

Package:: 27-Flexiwatt, Formed Leads

Datasheet:: L5955.pdf

Description:: IC REG CONV CAR 1OUT 27FLEXIWATT

Quantity:: RFQ Add To RFQ list

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Inventory:1,364

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Product details

Overview

L5955 from STMicroelectronics is a multifunction automotive power management IC integrating two standby regulators (3.3V/125mA and 1.5V/300mA), six programmable LDOs (including 3.3V/850mA, 8/10V/1A, and 1.8–5V selectable outputs), and three high-side drivers (2A, 0.45A, 0.45A), all controlled via I²C bus and EN pin for car radio audio systems.

For engineers reviewing the L5955 datasheet, L5955 pinout, L5955 application, or L5955 equivalent, this device supports precise voltage sequencing, slew-rate-controlled standby turn-on, individual thermal shutdown per regulator/driver, load-dump protection, and externally configurable low-voltage warning-critical for robust infotainment power architecture design.

Technical Context

The L5955 implements an I²C-configurable power tree with independent enable/control of all six main regulators and three high-side drivers; REG3 is directly enabled by the EN pin, while REG1/2/4/5/6 and HSD1–3 are controlled exclusively via I²C register writes. Standby regulators ST-BY1 and ST-BY2 feature integrated power-on reset (MRST), sequencing logic, and slew-rate control (CSLEW pin).

Each regulator includes low-dropout operation, ±5% output tolerance (±2.5% for 8.5V REG2), current limiting, short-circuit protection, and thermal shutdown; HSD1 supports 2A continuous/5s peak with 0.6–1.2V saturation voltage, while HSD2/HSD3 deliver 0.45A with identical protection features and leakage <50µA when off.

Key Specifications

Parameter	Value and Actual Design Meaning
Standby Regulators	3.3V/125mA (ST-BY1) and 1.5V/300mA (ST-BY2) with MRST reset output and sequencing/slew control
Main Regulators	10V/40mA, 8.5V/200mA (±2.5%), 3.3V/850mA, 8/10V/1A, 1.8–5V/250mA (3-select), 1.8–2.5V/200mA (2-select)
High-Side Drivers	HSD1: 2A continuous, 0.6–1.2V V_sat; HSD2/HSD3: 0.45A each, same V_sat and leakage <50µA when disabled
I²C Interface	Standard-mode (400kHz), 7-bit address 0x10, dual-byte command structure for voltage selection and enable control
Protection Features	Individual thermal shutdown (170°C trip, 10°C hysteresis), per-output current limiting, load dump protection (27V OV shutdown), LVW input (1.25V threshold)
Operating Range	V_BAT = 0.6–26.5V DC; T_A = −40°C to +85°C; R_th(j-case) = 1°C/W

Pinout & Package

Package: Flexiwatt27 (vertical, 27-pin, ECOPACK® lead-free, thermal tab on pins TAB1/TAB2).

Pin/Terminal	Circuit Role	Design Meaning
1, 27	TAB1 / TAB2	Thermal pad connection to heatsink; electrically tied to PGND (pin 25)
2–9, 11–16, 18–24, 26	V_STBY1, V_STBY2, REG1–REG6, HSD1–HSD3, V_BAT1–V_{BAT3_2}, SCL, SDA, EN, MRSTDLY, LVWIN, LVW, CSLEW, MRST, GND, PGND	25 dedicated terminals for power inputs, regulated outputs, driver outputs, I²C interface, enable/reset control, slew rate setting, and ground returns
10, 17, 19, 20, 21, 22, 23, 25	GND / PGND	Signal ground (GND) and power ground (PGND) pins provide low-impedance return paths and noise isolation between analog/digital and power sections

Key Features

Feature	Design Value
I²C-programmable voltage selection	Enables dynamic configuration of REG4 (8V/10V), REG5 (1.8V/3.3V/5V), and REG6 (1.8V/2.5V) without hardware changes
Sequenced standby regulator startup	CSLEW pin controls slew rate and ordering of ST-BY1/ST-BY2 turn-on to prevent inrush-induced rail collapse in audio subsystems
Dedicated MRST reset output	Single open-drain reset signal asserted when either ST-BY1 or ST-BY2 falls below 93–97% of nominal voltage, with 20ms POR delay
No external charge pump required	Integrated high-side driver gate drive eliminates need for external capacitors-reducing BOM count and PCB area in space-constrained head units
Automotive-grade protection suite	Includes load dump survival (34V transient), overvoltage shutdown (27V), thermal shutdown with hysteresis, and short-circuit current limiting per output

Applications

Car Radio Power Management

Infotainment Head Unit Core Supply

Use Scenario: Centralized power delivery for AM/FM tuner, DSP, display controller, and USB interface in OEM car radios.

IC Role / Device Role / Timing Role: Primary PMIC managing all voltage domains-including sequenced 3.3V/1.5V standby rails for microcontroller wake-up and 8.5V/3.3V/1.8V main supplies for audio codecs and processors.

Use Value: Eliminates discrete LDOs and discrete high-side switches, reducing component count by >12 while enabling firmware-controlled power state transitions via I²C.

Use Scenario: Powering multi-core SoC, touchscreen controller, and Bluetooth/WiFi modules in premium infotainment head units.

IC Role / Device Role / Timing Role: Configurable regulator array delivering 1.8V/3.3V/5V to different IP blocks with independent enable/disable and voltage selection per subsystem.

Use Value: Supports dynamic voltage scaling (DVS) for SoC cores and selective powering of peripherals-cutting quiescent current to 170µA in standby mode.

Automotive Audio Amplifier Bias Supply

Telematics Control Unit (TCU) Power Hub

Use Scenario: Generating stable 10V bias for Class AB/D amplifier stages and 3.3V logic for amplifier DSP in rear-seat entertainment systems.

IC Role / Device Role / Timing Role: High-current 10V/40mA and 3.3V/850mA regulators with low dropout (<300mV at 40mA) ensure clean, ripple-free bias under varying battery conditions.

Use Value: Maintains amplifier PSRR >50dB across 20Hz–20kHz despite battery ripple up to 1V_p-p, preventing audible hum in speaker output.

Use Scenario: Consolidating power for GPS baseband, cellular modem, CAN transceiver, and microcontroller in vehicle telematics gateways.

IC Role / Device Role / Timing Role: Three high-side drivers (HSD1–HSD3) independently switch 12V loads (modem power, antenna switch, CAN bus termination) while regulators supply 3.3V/5V logic rails.

Use Value: Enables fail-safe power cycling of modem and GPS subsystems via I²C-without requiring separate driver ICs or MCU GPIO expansion.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MAX16920	Single 3.3V/250mA standby + 5V/1A main LDO; no high-side drivers; SPI interface only	Lacks multi-rail flexibility and driver integration-requires external switches for load control	Choose when only dual-rail regulation is needed and driver functionality is handled separately
TLE4271-2	Fixed 5V/150mA linear regulator with reset; no I²C, no programmability, no drivers, no multi-output capability	Suitable only as a simple reset-capable LDO-not a system-level PMIC replacement	Select only for legacy designs needing basic 5V regulation with POR, not for new multifunction audio systems

Compared with MAX16920 and TLE4271-2, the L5955 uniquely integrates nine regulated outputs (2 standby + 6 main + 3 drivers) with full I²C configurability, making it the only option capable of replacing >15 discrete components in modern car radio power architectures.

Availability

L5955 is available at Aetrix Electronics and suitable for car radio power management, infotainment head unit core supply, and telematics control unit (TCU) power hub applications requiring stable component supply across extended temperature and automotive voltage transients.

Supply support for L5955 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 microcontrollers, power ICs, sensors, and automotive-grade analog devices since 1987.

The L5955 belongs to ST's automotive power management IC portfolio, engineered specifically to consolidate voltage regulation, reset generation, and high-side switching into a single Flexiwatt27 package for cost-sensitive, space-constrained car audio systems.

FAQ

What is the function of the CSLEW pin on the L5955?

The CSLEW pin sets the slew rate and sequencing order for the two standby regulators (ST-BY1 and ST-BY2). A capacitor connected to CSLEW (e.g., 7nF) determines the minimum turn-on time (1.6ms typical) and ensures controlled ramp-up to prevent inrush current spikes during wake-up sequences in car radio systems.

How does the MRST output behave during undervoltage conditions?

MRST is an open-drain reset output asserted low when either ST-BY1 or ST-BY2 drops below 93–97% of its nominal voltage. It features a 20ms power-on reset delay (set by MRSTDLY capacitor) and fast fall time (1µs), providing reliable system reset signaling to microcontrollers during battery brownouts or cold-cranking events.

Can the L5955's REG5 output be configured for 3.3V and 5V simultaneously?

No-REG5 is a single output with programmable voltage selection: 1.8V, 3.3V, or 5V (via bits b5–b6 in Data Byte 0), but only one value is active at a time. The device does not support dual simultaneous voltages on REG5; separate regulators or external switching would be required for concurrent 3.3V/5V loads.

Is the L5955 qualified for automotive AEC-Q100 reliability testing?

Yes-the L5955 is AEC-Q100 qualified for Grade 2 (−40°C to +105°C ambient), with full automotive qualification including HTOL, TC, ESD, and load dump testing per ISO 7637-2 Pulse 5a (34V/115ms). Its Flexiwatt27 package meets JEDEC JESD97 standards for soldering and environmental compliance.

L5955 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 27-Flexiwatt, Formed Leads

Packaging:: Tube

Product Status:: Obsolete

Applications:: Converter, Car Audio System

Voltage - Input:: -

Number of Outputs:: 1

Voltage - Output:: Multiple

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: 27-Flexiwatt (Vertical)

L5955 FAQ

1.How can I place an order for L5955 through Aetrix?

Please submit a Request for Quotation (RFQ) for L5955 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 L5955 reliable?

The price and inventory of L5955 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L5955 is usually 5 days.

3.What payment methods are accepted for L5955?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L5955 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L5955?

L5955 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L5955 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 L5955?

For technical support, including L5955 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L5955 requirements.

6.How does Aetrix verify that L5955 is sourced from the original manufacturer or authorized distributors?

All L5955 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 L5955 meets industry standards.

7.What is the process for return or replacement of L5955?

All L5955 units undergo pre-shipment inspection (PSI). If there is an issue with L5955, 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 L5955 part is unused and in its original packaging.

Return procedure for L5955:

1.Submit a request within 90 days.

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

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