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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear + Switching

Allegro MicroSystems A8450KLBTR

Name: A8450KLBTR
Brand: Allegro MicroSystems
SKU: A8450KLBTR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: A8450KLBTR

Manufacturer:: Allegro MicroSystems

Category:: Voltage Regulators - Linear + Switching

Package:: 24-SOIC (0.295", 7.50mm Width)

Datasheet:: A8450KLBTR.pdf

Description:: IC REG QUAD BUCK/LINEAR 24SOIC

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Product details

Overview

A8450KLBTR from Allegro MicroSystems is an automotive-grade multi-output power management IC integrating a 5.7 V buck converter, dual 5 V linear regulators (digital and analog), a fixed 3.3 V LDO, and an adjustable 1.2–3.3 V LDO - all operating from 6–45 V input and rated for –40°C to +135°C ambient. It delivers up to 550 mA total regulated output current with <0.5% V5A–V5D tracking, short-to-battery protection on V5A, and foldback current limiting across all outputs.

For engineers reviewing the A8450KLBTR datasheet, A8450KLBTR pinout, A8450KLBTR application, or A8450KLBTR equivalent, this page provides verified pin functions, thermal performance data (R_θJA = 35°C/W), fault signaling (NFAULT/NPOR), ignition-switch enable (ENBAT), and microcontroller-controlled enable (ENB) - critical for under-hood ECU, ADAS domain controller, and body control module designs.

Technical Context

The A8450KLBTR implements a current-mode variable-frequency buck converter with soft-start, internal charge pump (CP1/CP2/VCP), and 100% duty-cycle capability below 12 V input. Its four independent linear regulator paths - V5D, V5A, V33, and VADJ - share a common VREG rail but feature separate current-limiting (CL33/CLADJ), feedback (FB), and base-drive (VADJBD/V33BD) circuitry.

Thermal shutdown (TJTSD = 175°C), thermal warning (TJTW = 160°C), and UVLO thresholds per rail (e.g., VUVLOV33 = 2.95 V, VUVLOV5 = 4.50 V) are internally monitored. POR delay (tPOR = 100 ms typ. with 0.47 µF C9) and open-drain NFAULT/NPOR outputs provide system-level diagnostics without external logic.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	6–45 V - supports 12 V and 24 V automotive batteries including load-dump transients.
Buck Output (VREG)	5.7 V typical, 5.5–5.8 V - powers all downstream linear regulators; dropout mode active below 6.5 V.
V5D / V5A Output	5.0 V ±2%, 200 mA each - analog regulator includes short-to-battery protection; tracking ≤±25 mV over temperature.
V33 Output	3.300 V ±2%, 3.234–3.366 V - fixed LDO with foldback current limit set by R3.
VADJ Output Range	1.2–3.3 V - adjustable via FB pin (VFB = 1.20 V) and external resistor divider (R1/R2).
Quiescent Current	≤10 µA in disabled mode - enables low-power sleep states for always-on vehicle modules.
Operating Temperature	–40°C to +135°C ambient - qualified per AEC-Q100 Grade 1; R_θJA = 35°C/W on 4-layer PCB.

Pinout & Package

Package: 24-pin SOIC-W (suffix LB), internally fused power ground pins (pins 6–7 and 18–19) for enhanced thermal performance and reduced ground bounce.

Pin/Terminal	Circuit Role	Design Meaning
LX	Buck switch node	Connects to external inductor (L1) and Schottky catch diode (D1); voltage swings between GND and VBB.
ENBAT	High-voltage enable input	Accepts 2.7–45 V ignition/battery-switch signal; enables device with edge-triggered logic.
V33	Fixed 3.3 V LDO output	Regulated supply for MCU I/O or sensors; current limited via CL33 pin and R3.
V33BD	3.3 V base drive output	Drives external npn pass transistor Q1 base; sets V33 output headroom and transient response.
CL33	3.3 V current limit sense	Connects to R3; sets foldback threshold (VOC = 200 mV typ.) for Q1 short-circuit protection.
GND	Power ground (pins 6, 7, 18, 19)	Fused internal ground connections reduce thermal resistance and improve current sharing.
VREG	Buck converter output	Main 5.7 V rail feeding all linear regulators; monitored for UVLO (VUVLOVREG = 5.15 V).
V5D	Digital 5 V LDO output	Supplies digital logic; ±2% tolerance, 200 mA max, foldback-limited to 50 mA during short.
NFAULT	Open-drain fault indicator	Pulled low on V5A short-to-battery, V5A/V5D UVLO, or thermal warning (TJ ≥ 160°C).
NPOR	Open-drain power-on reset	Asserted low during V33/VADJ UVLO, ENB/ENBAT low, or VREG UVLO; delay set by C9 on CPOR.
V5A	Analog 5 V LDO output	Low-noise supply for ADCs/sensors; includes short-to-battery protection and tracks V5D within ±0.5%.
VBB	Main input supply	6–45 V battery input; absolute max rating = –40 V (reverse polarity tolerant).
CP2 / CP1 / VCP	Charge pump terminals	Generate gate drive above VBB for internal N-MOSFET buck switch; requires C7 (0.1 µF) and C8 (0.1 µF).
VREG11	VREG monitor output	Open-collector signal indicating VREG regulation status; used for system-level power sequencing.
ENB	Logic-level enable input	0–6.5 V microcontroller/DSP control signal; enables/disables device and initiates reset sequence.
CPOR	POR capacitor connection	Connects external timing capacitor (C9) to set POR delay: tPOR = 213 ms/µF (e.g., 0.47 µF → 100 ms).
CLADJ	Adjustable regulator current limit	Sets foldback threshold for VADJ output via R4; same VOC = 200 mV reference as CL33.
VADJBD	Adjustable regulator base drive	Drives external npn pass transistor Q2 base; enables stable operation down to 1.2 V output.
FB	Feedback input	1.20 V reference point for VADJ output; connects to resistor divider (R1/R2) to set VOUT = 1.2 × (1 + R1/R2).
VIN	Internal VREG bypass	Connects to C1 (1 µF ceramic) to stabilize VREG regulation loop and suppress high-frequency noise.
H.V.	High-voltage sense	Internal monitoring node for VBB overvoltage detection; not user-accessible.

Key Features

Feature	Design Value
Dual 5 V tracking regulators	V5A and V5D maintain ≤±25 mV offset across –40°C to +135°C - eliminates need for external trimming in safety-critical domains.
Ignition-switch enable (ENBAT)	Direct interface to 12/24 V vehicle battery or ignition line - no level-shifter required for wake-up from sleep.
Short-to-battery protection on V5A	Active protection against V5A pin shorted to VBB - prevents damage during wiring faults in automotive harnesses.
Adjustable 1.2–3.3 V LDO	Configurable output via FB pin and external resistors - supports diverse core voltages for MCUs, FPGAs, and ASICs.
Thermal warning & shutdown	Early TJ ≥ 160°C warning (NFAULT) and hard shutdown at 175°C - enables graceful system degradation before failure.

Applications

Engine Control Unit (ECU)	Advanced Driver Assistance Systems (ADAS)
Use Scenario: Powering 32-bit MCU, CAN transceiver, and analog sensor front-end in under-hood engine bay. IC Role / Device Role / Timing Role: Central power manager delivering isolated 5 V (digital/analog), 3.3 V, and adjustable core voltage from 12 V battery with thermal resilience. Use Value: Eliminates need for discrete LDOs and tracking circuits; V5A short-to-battery protection prevents field failures from harness shorts.	Use Scenario: Supplying radar SoC, camera ISP, and inertial measurement unit in ADAS domain controller. IC Role / Device Role / Timing Role: Multi-rail PMIC providing tightly tracked 5 V rails for mixed-signal processing and low-noise analog sensing. Use Value: <0.5% V5A–V5D tracking ensures consistent ADC reference and clock buffer biasing across temperature extremes.
Body Control Module (BCM)	Infotainment Head Unit
Use Scenario: Managing power for door module MCU, LIN transceivers, and LED drivers in passenger compartment. IC Role / Device Role / Timing Role: High-efficiency buck + LDO solution enabling low-quiescent sleep mode (<10 µA) and fast wake-up via ENBAT. Use Value: Meets OEM requirements for <50 µA standby current while supporting 135°C under-dash operation.	Use Scenario: Powering application processor, audio codec, and display interface in center-stack infotainment system. IC Role / Device Role / Timing Role: Configurable VADJ rail (1.2–3.3 V) supplies variable-core processors; V33 powers USB PHY and SDIO interfaces. Use Value: Single-chip solution reduces BOM count vs. discrete regulators and simplifies layout of high-density PCBs.

Engine Control Unit (ECU)

Advanced Driver Assistance Systems (ADAS)

Use Scenario: Powering 32-bit MCU, CAN transceiver, and analog sensor front-end in under-hood engine bay.

IC Role / Device Role / Timing Role: Central power manager delivering isolated 5 V (digital/analog), 3.3 V, and adjustable core voltage from 12 V battery with thermal resilience.

Use Value: Eliminates need for discrete LDOs and tracking circuits; V5A short-to-battery protection prevents field failures from harness shorts.

Use Scenario: Supplying radar SoC, camera ISP, and inertial measurement unit in ADAS domain controller.

IC Role / Device Role / Timing Role: Multi-rail PMIC providing tightly tracked 5 V rails for mixed-signal processing and low-noise analog sensing.

Use Value: <0.5% V5A–V5D tracking ensures consistent ADC reference and clock buffer biasing across temperature extremes.

Body Control Module (BCM)

Infotainment Head Unit

Use Scenario: Managing power for door module MCU, LIN transceivers, and LED drivers in passenger compartment.

IC Role / Device Role / Timing Role: High-efficiency buck + LDO solution enabling low-quiescent sleep mode (<10 µA) and fast wake-up via ENBAT.

Use Value: Meets OEM requirements for <50 µA standby current while supporting 135°C under-dash operation.

Use Scenario: Powering application processor, audio codec, and display interface in center-stack infotainment system.

IC Role / Device Role / Timing Role: Configurable VADJ rail (1.2–3.3 V) supplies variable-core processors; V33 powers USB PHY and SDIO interfaces.

Use Value: Single-chip solution reduces BOM count vs. discrete regulators and simplifies layout of high-density PCBs.

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-output automotive regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TPS65381A-Q1	Triple LDO + buck (3.3/5/5 V), integrated watchdog, no adjustable output; lower I_Q (3 µA) but no V5A short-to-battery protection.	Targeted at ASIL-B safety systems requiring watchdog; lacks analog-domain short protection needed for sensor clusters.	Select when functional safety (ISO 26262) monitoring is mandatory and adjustable output is unnecessary.
MAX20091ATPA/V+T	Quad LDO + buck (3.3/5/5/adj), higher VBB max (60 V), integrated SPI interface; no V5A short-to-battery protection.	Supports 42 V commercial vehicles; programmable via SPI but adds firmware complexity and cost.	Select for heavy-duty truck applications requiring >45 V input and digital configuration flexibility.

Compared with TPS65381A-Q1 and MAX20091ATPA/V+T, the A8450KLBTR uniquely combines V5A short-to-battery protection, 1.2–3.3 V adjustability, and ignition-switch enable in a single SOIC-W package - making it optimal for cost-sensitive, thermally demanding automotive ECUs where analog rail integrity is critical.

Availability

A8450KLBTR is available at Aetrix Electronics and suitable for engine control units, ADAS domain controllers, and body control modules requiring stable component supply across extended temperature and high-reliability automotive environments.

Supply support for A8450KLBTR 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

Allegro MicroSystems is a U.S.-based semiconductor company specializing in high-performance power ICs and magnetic sensors for automotive and industrial markets.

The A8450 product line delivers integrated multi-rail power solutions for automotive electronic control units, designed to replace discrete regulator combinations while meeting AEC-Q100 Grade 1 requirements and under-hood thermal constraints.

FAQ

What is the maximum total output current supported by the A8450KLBTR?

The A8450KLBTR supports up to 550 mA total load current across all regulated outputs (V5D, V5A, V33, VADJ) when VREG is in regulation (VBB ≥ 6.5 V). This assumes typical conditions: VBB = 14 V, TA = 25°C, and proper thermal design per the 35°C/W R_θJA specification. The internal buck switch current limit is 1.2 A typical, but linear regulator headroom and thermal limits constrain practical total output.

How does the A8450KLBTR achieve V5A–V5D output tracking?

The A8450KLBTR achieves <0.5% V5A–V5D tracking through dedicated analog feedback and error amplification circuitry that actively synchronizes the two 5 V LDOs during power-up and steady-state operation. Tracking is guaranteed across –40°C to +135°C ambient and holds within ±25 mV for loads between 50–200 mA per rail. This eliminates need for external calibration or trimming in precision analog subsystems.

Can the A8450KLBTR operate with a 42 V input supply?

Yes, the A8450KLBTR supports input voltages up to 45 V, making it compatible with 42 V commercial vehicle systems. Absolute maximum VBB rating is –40 V (reverse polarity), and electrical characteristics are specified from 6–45 V. For 42 V applications, use 100 V-rated input capacitors (C7/C8) and ensure thermal design accommodates higher power dissipation at elevated VBB.

What external components are mandatory for basic A8450KLBTR operation?

Mandatory external components for basic A8450KLBTR operation include: COUT (100 µF low-ESR electrolytic on VREG), L1 (100 µH power inductor), D1 (1 A Schottky diode), C7/C8 (0.1 µF ceramic on CP1/CP2), C9 (0.47 µF on CPOR for 100 ms POR delay), and R1/R2 (for VADJ output setting). Pass transistors Q1/Q2 and current-limit resistors R3/R4 are required only if using V33 or VADJ outputs.

Does the A8450KLBTR support AEC-Q100 qualification?

Yes, the A8450KLBTR is qualified per AEC-Q100 Grade 1, covering –40°C to +135°C ambient operation. This qualification includes stress testing for temperature cycling, humidity, ESD, and mechanical shock - confirming suitability for under-hood automotive applications such as engine control, transmission control, and ADAS sensor modules.

A8450KLBTR Specifications

Product attributes: Attribute value

Manufacturer:: Allegro MicroSystems

Series:: -

Package/Case:: 24-SOIC (0.295", 7.50mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Discontinued at Digi-Key

Topology:: Step-Down (Buck) (1), Linear (LDO) (4)

Number of Outputs:: 4

Frequency - Switching:: -

Voltage/Current - Output 1:: 3.3V, 200mA

Voltage/Current - Output 2:: 1.2V ~ 3.3V, 200mA

Voltage/Current - Output 3:: 5V, 200mA

w/LED Driver:: No

w/Supervisor:: No

w/Sequencer:: Yes

Voltage - Supply:: 6V ~ 45V

Operating Temperature:: -40°C ~ 135°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 24-SOIC

A8450KLBTR FAQ

1.How can I place an order for A8450KLBTR through Aetrix?

Please submit a Request for Quotation (RFQ) for A8450KLBTR 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 A8450KLBTR reliable?

The price and inventory of A8450KLBTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A8450KLBTR is usually 5 days.

3.What payment methods are accepted for A8450KLBTR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A8450KLBTR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for A8450KLBTR?

A8450KLBTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your A8450KLBTR 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 A8450KLBTR?

For technical support, including A8450KLBTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A8450KLBTR requirements.

6.How does Aetrix verify that A8450KLBTR is sourced from the original manufacturer or authorized distributors?

All A8450KLBTR 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 A8450KLBTR meets industry standards.

7.What is the process for return or replacement of A8450KLBTR?

All A8450KLBTR units undergo pre-shipment inspection (PSI). If there is an issue with A8450KLBTR, 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 A8450KLBTR part is unused and in its original packaging.

Return procedure for A8450KLBTR:

1.Submit a request within 90 days.

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

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