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

STMicroelectronics A5975AD

Name: A5975AD
Brand: STMicroelectronics
SKU: A5975AD
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: A5975AD

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

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

Datasheet:: A5975AD.pdf

Description:: IC REG BUCK ADJ 2.5A 8HSOP

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Product details

Overview

A5975AD from STMicroelectronics is a monolithic step-down switching regulator IC designed for automotive power conversion, featuring an internal P-channel DMOS switch (R_DS(on) = 250 mΩ), 2.5 A DC output current capability, 4–36 V input range, and fixed 500 kHz switching frequency - deployed in engine control units, ADAS camera modules, and infotainment power rails.

For engineers reviewing the A5975AD datasheet, A5975AD pinout, A5975AD application, or A5975AD equivalent, this page delivers verified technical context, validated pin functions, automotive-grade thermal performance data (R_THJ-A = 40 °C/W), and real-world synchronization and inhibit behavior under cold-crank conditions.

Technical Context

The A5975AD integrates a voltage feed-forward PWM controller with a transconductance error amplifier (g_m = 2.3 mS, DC open-loop gain = 50–65 dB) and dual-stage current protection: pulse-by-pulse limiting (3.1–4.1 A typical limit) plus frequency-shifting during overload. Its internal 3.3 V reference (±2% tolerance, 5–10 mV line regulation) feeds both feedback and sync circuitry.

It operates in continuous conduction mode with 100% duty-cycle low-dropout capability and supports zero-load operation via active quiescent current control (I_qst-by = 50–100 µA). The HSOP8 exposed-pad package enables thermal resistance of 40 °C/W on standard demo board layouts, critical for under-hood ambient temperatures up to +125 °C.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	4 V to 36 V - supports cold-crank (4 V) and load-dump (36 V) transients per ISO 7637-2.
Output Current	Up to 2.5 A DC - sustained under thermal limits using HSOP8 exposed pad (R_THJ-A = 40 °C/W).
Switching Frequency	500 kHz (±15%) - fixed internal oscillator enables predictable EMI filtering and compact LC design.
Reference Voltage	3.3 V ±2% - stable internal VREF supplied directly to SYNCH and COMP blocks without external capacitor.
Feedback Threshold	1.235 V ±3.5% - sets base output voltage; adjustable to 35 V via external resistor divider on FB pin.
Current Limit	3.1 A min (typ. 3.6 A) - pulse-by-pulse overcurrent protection prevents MOSFET failure during short circuits.
Quiescent Current	5–7 mA operating / 50–100 µA standby - enables always-on subsystems with minimal battery drain.

Pinout & Package

Package: HSOP8 with exposed thermal pad (mechanical outline per DocID018761 Rev 2, Table 10), optimized for automotive thermal cycling and solder joint reliability.

Pin/Terminal	Circuit Role	Design Meaning
1 OUT	Power output node	Connects to LC filter output; carries full switched current; requires low-ESR ceramic output capacitor.
2 SYNCH	Master/slave sync I/O	Accepts or outputs 500 kHz clock signal; enables multi-rail noise reduction when tied across multiple A5975ADs.
3 INH	Inhibit control input	Active-high logic: >2.2 V disables regulator; internal pull-up ensures safe shutdown if left floating.
4 COMP	Error amplifier output	Drives external RC compensation network; source/sink capability (190 µA/1.5 mA) stabilizes loop response.
5 FB	Voltage feedback input	Senses output via resistive divider; 1.235 V threshold enables precise output programming from 1.235 V to 35 V.
6 VREF	3.3 V reference output	Stable, low-noise reference for external circuitry; no bypass cap required per datasheet.
7 GND	Signal and power ground	Common return for analog and power paths; must connect to exposed pad for thermal and EMI integrity.
8 VCC	Main power input	Unregulated input (4–36 V); powers internal bias circuitry and high-side driver; decoupling mandatory.

Key Features

Feature	Design Value
Voltage feed-forward control	Compensates for input voltage transients in real time, improving line regulation and transient response without loop redesign.
Internal P-channel DMOS switch	R_DS(on) = 250 mΩ typ., eliminating external high-side FET and reducing BOM count and layout area.
Zero-load operation	Maintains regulation at 0 A output while drawing only 2.7 mA quiescent current - essential for always-on vehicle networks.
Thermal shutdown with hysteresis	Triggers at T_J = 150 °C ±10 °C and holds off until cooldown to ~135 °C, preventing thermal runaway in sealed enclosures.
Feedback disconnection protection	Detects open FB trace or failed divider and forces shutdown - avoids dangerous overvoltage on downstream loads.

Applications

Engine Control Unit (ECU) Power Supply

ADAS Camera Module Rail

Use Scenario: Powers microcontroller, CAN transceiver, and sensor interface in gasoline/diesel ECU under wide temperature and voltage stress.

IC Role / Device Role / Timing Role: Primary 5 V or 3.3 V buck converter; handles cold-crank (4 V) and load-dump (36 V) events without dropout or reset.

Use Value: 100% duty cycle operation maintains regulation down to 4 V input; AEC-Q100 qualification ensures functional safety compliance.

Use Scenario: Supplies image sensor and ISP in forward-facing radar/camera fusion module mounted near windshield.

IC Role / Device Role / Timing Role: High-efficiency 1.8 V rail generator; synchronized to other power rails to suppress beat-frequency EMI in sensitive analog video path.

Use Value: 500 kHz fixed frequency + SYNCH pin enables deterministic noise spectrum; R_THJ-A = 40 °C/W sustains 2.5 A at +105 °C ambient.

Infotainment System Core Logic

Body Control Module (BCM) Subsystem

Use Scenario: Delivers stable 1.1 V core voltage to application processor in head-unit under varying battery conditions.

IC Role / Device Role / Timing Role: Adjustable-output buck regulator; configured via FB divider for precise low-voltage rail generation.

Use Value: Output programmable from 1.235 V to 35 V supports diverse SoC requirements; ±2% VREF ensures tight output accuracy.

Use Scenario: Powers LIN transceiver, EEPROM, and LED drivers in door module with ultra-low standby current demand.

IC Role / Device Role / Timing Role: Always-on auxiliary supply; uses INH pin for controlled wake/sleep sequencing with MCU.

Use Value: 50–100 µA inhibit-mode current minimizes parasitic drain; internal current limiting protects against wiring faults in harnesses.

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM5164QDDARQ1	40 V max input, 0.5 A output, external MOSFET required; no integrated P-FET.	Lacks integrated high-side switch and automotive thermal rating (R_THJ-A = 62 °C/W).	Choose when lower cost and external FET flexibility outweigh integration and thermal needs.
TPS54560QDGQRQ1	60 V max input, 5 A output, but 340 kHz fixed freq; higher quiescent current (18 µA vs 50 µA in standby).	Higher output current but less suitable for space-constrained modules due to larger external components.	Prefer for higher-power BCM or gateway applications where 5 A and 60 V margin are mandatory.

Compared with LM5164QDDARQ1 and TPS54560QDGQRQ1, the A5975AD uniquely combines 2.5 A output, integrated P-FET, 40 °C/W thermal resistance, and AEC-Q100 qualification in HSOP8 - making it optimal for compact, thermally demanding automotive subsystems requiring minimal external components.

Availability

A5975AD is available at Aetrix Electronics and suitable for engine control units, ADAS camera modules, and infotainment systems requiring stable component supply across automotive production lifecycles.

Supply support for A5975AD 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, specializing in automotive, industrial, and power management ICs with vertical manufacturing and AEC-Q100-aligned quality systems.

The A5975AD belongs to ST's automotive-grade monolithic DC-DC regulator product line, engineered specifically for under-hood power conversion where cold-crank resilience, thermal robustness, and functional safety compliance are non-negotiable.

FAQ

What is the minimum input voltage required for A5975AD to regulate during cold-crank conditions?

The A5975AD operates down to 4 V input, enabling uninterrupted regulation during automotive cold-crank events defined by ISO 16750-2. This is achieved via low-threshold UVLO and 100% duty-cycle capability - confirmed in datasheet Section 2.1 and Figure 18.

Can the A5975AD synchronize to an external clock, or only to other A5975AD devices?

The SYNCH pin supports bidirectional master/slave operation: it can accept an external 500 kHz clock (within ±15% tolerance) or drive other A5975ADs as master. Internal sync circuitry is powered by VREF, requiring ≥100 nF capacitor on VREF for stability - per Section 5.3 and Figure 6.

Does the A5975AD require an external bootstrap capacitor?

No. The A5975AD uses an internal P-channel MOSFET for the high-side switch, eliminating the need for a bootstrap capacitor or external gate driver. This simplifies layout and improves reliability in high-vibration environments - explicitly stated in the Description section and Figure 4.

How does the A5975AD protect against feedback resistor divider failure?

It implements dedicated feedback disconnection protection: if the FB pin is open-circuited or the divider fails, the device detects loss of feedback voltage and shuts down to prevent uncontrolled overvoltage - detailed in Section 6.1 and functional block diagram (Figure 3).

A5975AD Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

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

Packaging:: Tube

Product Status:: Obsolete

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 1

Voltage - Input (Min):: 4V

Voltage - Input (Max):: 36V

Voltage - Output (Min/Fixed):: 1.235V

Voltage - Output (Max):: 35V

Current - Output:: 2.5A

Frequency - Switching:: 500kHz

Synchronous Rectifier:: No

Operating Temperature:: -40°C ~ 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q100

Mounting Type:: Surface Mount

Supplier Device Package:: 8-HSOP

A5975AD FAQ

1.How can I place an order for A5975AD through Aetrix?

Please submit a Request for Quotation (RFQ) for A5975AD 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 A5975AD reliable?

The price and inventory of A5975AD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A5975AD is usually 5 days.

3.What payment methods are accepted for A5975AD?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A5975AD transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for A5975AD?

A5975AD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your A5975AD 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 A5975AD?

For technical support, including A5975AD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A5975AD requirements.

6.How does Aetrix verify that A5975AD is sourced from the original manufacturer or authorized distributors?

All A5975AD 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 A5975AD meets industry standards.

7.What is the process for return or replacement of A5975AD?

All A5975AD units undergo pre-shipment inspection (PSI). If there is an issue with A5975AD, 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 A5975AD part is unused and in its original packaging.

Return procedure for A5975AD:

1.Submit a request within 90 days.

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

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