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

STMicroelectronics L5986ATR

Name: L5986ATR
Brand: STMicroelectronics
SKU: L5986ATR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L5986ATR

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

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

Datasheet:: L5986ATR.pdf

Description:: IC REG BUCK ADJ 2.5A 8HSOP

Quantity:: RFQ Add To RFQ list

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Inventory:4,119

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Product details

Overview

L5986ATR from STMicroelectronics is a 2.5 A synchronous step-down switching regulator with integrated high-side P-channel MOSFET, designed for DC-DC conversion in space-constrained power rails. It operates from 2.9 V to 18 V input, delivers adjustable output down to 0.6 V, features 250 kHz–1 MHz programmable switching frequency, internal soft-start, and 100% duty-cycle low-dropout operation - used in LCD TV power supplies and FPGA core voltage regulation.

For engineers reviewing the L5986ATR datasheet, L5986ATR pinout, L5986ATR application, or L5986ATR equivalent, key selection criteria include input voltage range (2.9–18 V), output current capability (2.5 A), thermal resistance (40 °C/W in HSOP8), synchronization capability via SYNCH pin, and zero-load quiescent current (20–30 µA) for always-on systems.

Technical Context

The L5986ATR implements voltage-mode PWM control with feedforward compensation for stable line transient response. Its oscillator supports free-running (250 kHz) or resistor-programmed operation up to 1 MHz, and external synchronization via the SYNCH pin enables phase-shifted multi-phase operation with matched devices.

Functional blocks include a 0.6 V reference error amplifier with COMP pin for Type II/III loop compensation, peak-current-limited P-channel MOSFET driver (R_DS(on) = 140–220 mΩ), hiccup-mode overcurrent protection, and hysteretic thermal shutdown (150 °C trip, 130 °C recovery). The inhibit (INH) pin provides logic-level enable/disable with <30 µA standby current.

Key Specifications

Parameter	Value and Actual Design Meaning
Output current	2.5 A continuous - sufficient for FPGA core or audio amplifier rail without external boost
Input voltage range	2.9 V to 18 V - supports 3.3 V bus and 12 V industrial inputs
Output voltage range	0.6 V to V_IN - enables 1.2 V, 1.8 V, 3.3 V, or 5 V regulation with resistor divider
Switching frequency	250 kHz (default) to 1 MHz - higher frequencies reduce inductor size; feedforward maintains PWM gain stability
R_DS(on)	140–220 mΩ - limits conduction loss at full load; enables >90% efficiency at 12 V→3.3 V/2 A
Quiescent current	20–30 µA in standby - suitable for battery-backed or always-on subsystems
Thermal resistance (HSOP8)	40 °C/W - allows 2.5 A operation at +85 °C ambient with minimal heatsinking

Pinout & Package

Available in HSOP8 (exposed pad) and VFQFPN 3×3 mm –8L packages. The HSOP8 variant offers lower thermal resistance (40 °C/W vs. 60 °C/W), making it preferred for high-current or thermally constrained applications.

Pin/Terminal	Circuit Role	Design Meaning
OUT	Regulator output	Power node connected to inductor and output capacitor; carries full load current and switching ripple
SYNCH	Synchronization I/O	Master/slave sync interface: floating = 180° phase-shifted clock; driven externally = zero-phase lock to external source
INH	Inhibit control (active-high)	Logic-level enable: <0.6 V = ON, >1.9 V = OFF; internal pull-up disables device if left floating
COMP	Error amplifier output	Connects to external compensation network (Type II/III) to stabilize feedback loop across load/line transients
FB	Feedback input	Senses output voltage via resistor divider; internal 0.6 V reference sets regulation threshold
FSW	Frequency set/sync input	Resistor-to-ground sets frequency (250 kHz–1 MHz); open = default 250 kHz; external clock overrides
GND	Power and signal ground	Common return for power path, control circuitry, and exposed thermal pad (HSOP8/VFQFPN)
VCC	Unregulated input supply	Bias rail for internal circuitry; must be ≥2.9 V to enable UVLO; powers gate driver and error amplifier

Key Features

Feature	Design Value
Voltage feedforward	Maintains constant PWM gain across input voltage changes by dynamically adjusting sawtooth slope
Programmable frequency up to 1 MHz	Enables compact magnetics and noise spectrum shifting away from sensitive bands (e.g., audio or RF)
Hiccup-mode overcurrent protection	Prevents thermal runaway during sustained overload or short-circuit while allowing automatic recovery
100% duty-cycle operation	Supports dropout-free regulation when V_IN ≈ V_OUT, e.g., 3.3 V input → 3.3 V output with minimal headroom
Zero-load quiescent current	20–30 µA standby draw enables use in always-on system rails without significant battery drain

Applications

Consumer LCD TV Power Supply

FPGA Core Voltage Regulation

Use Scenario: Generating 1.2 V or 1.8 V core supply for mid-range FPGAs in flat-panel TV mainboards with limited PCB area.

IC Role / Device Role / Timing Role: Primary buck converter delivering regulated core voltage; synchronized to system clock via SYNCH pin to reduce EMI.

Use Value: Integrated MOSFET eliminates external high-side switch; 2.5 A rating covers typical FPGA dynamic loads; 40 °C/W HSOP8 package sustains operation without forced air.

Use Scenario: Providing clean, tightly regulated 1.2 V supply to Xilinx Spartan-6 or Intel Cyclone IV FPGA core logic under variable load conditions.

IC Role / Device Role / Timing Role: Constant-frequency voltage-mode regulator with programmable soft-start (7.4–9.1 ms) to prevent inrush into large FPGA decoupling banks.

Use Value: COMP pin enables precise loop compensation for fast load-step response (<10 µs recovery); FB pin tolerance (±0.7%) ensures ±1% output accuracy.

Automotive Infotainment Audio Rail

Industrial PLC I/O Module Supply

Use Scenario: Generating 5 V or 3.3 V bias for Class D audio amplifiers and DSPs in car audio head units operating from 9–16 V battery input.

IC Role / Device Role / Timing Role: Input-wide buck regulator with UVLO (2.9 V turn-on) and thermal shutdown (150 °C) for under-hood reliability.

Use Value: 2.9–18 V input range accommodates cold-crank (6.5 V) and load-dump (18 V); hiccup protection prevents latch-up during speaker short events.

Use Scenario: Powering isolated I/O channel circuitry (ADCs, digital isolators, level shifters) in DIN-rail mounted PLC modules with 24 V nominal input.

IC Role / Device Role / Timing Role: Compact, robust DC-DC stage converting 24 V to 3.3 V or 5 V for microcontroller peripherals and sensor interfaces.

Use Value: Low 30 µA standby current supports deep-sleep modes; INH pin enables firmware-controlled power gating of I/O banks.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP2315DJ-LF-Z	2.5 A, 4.5–24 V input, fixed 3.3 V or 5 V output; no adjustable V_OUT or SYNC pin	Lacks programmable frequency and synchronization; suited only for fixed-output, single-rail designs	Select when simplicity and BOM count reduction outweigh flexibility needs
TPS54202DRCT	2 A, 4.5–17 V input, 0.6 V reference, 500 kHz–2.5 MHz adjustable frequency, EN/SYNC pins	Lower current rating; higher max frequency; requires external high-side MOSFET	Choose for higher-frequency, lower-profile designs where external FET layout is acceptable

Compared with MP2315DJ-LF-Z and TPS54202DRCT, the L5986ATR uniquely combines 2.5 A current, wide 2.9–18 V input, adjustable output, and true synchronization capability in a single IC - enabling multi-rail coordination and superior thermal performance in HSOP8.

Availability

L5986ATR is available at Aetrix Electronics and suitable for consumer LCD TV power supplies, FPGA core voltage regulation, automotive infotainment audio rails, and industrial PLC I/O module supplies requiring stable component supply and long-term manufacturability.

Supply support for L5986ATR 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, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The L5986 belongs to ST's high-efficiency monolithic DC-DC regulator product line, engineered for space-constrained, thermally demanding applications requiring integrated power switches and robust protection features.

FAQ

What is the minimum input voltage required for L5986ATR startup?

The L5986ATR has a guaranteed turn-on threshold of 2.9 V with 175–300 mV hysteresis. Below 2.9 V, the UVLO circuit holds the device disabled. This allows reliable operation directly from a 3.3 V bus or post-LDO 3.3 V rail, even under brownout conditions.

Can L5986ATR operate in 100% duty cycle mode, and what does that enable?

Yes - the L5986ATR supports true 100% duty cycle operation, meaning the high-side MOSFET remains continuously on when V_OUT ≥ V_IN − V_SW. This enables dropout-free regulation in near-input-output scenarios, such as generating 3.3 V from a 3.6 V Li-ion battery or 5 V from a 5.2 V USB PD rail.

How does the SYNCH pin function when connecting two L5986ATR devices?

When SYNCH pins of two L5986ATR devices are tied together, the higher-frequency unit becomes master and the other slave. Their power switches operate 180° out-of-phase, reducing RMS input capacitor current by up to 30% and easing EMI filtering - confirmed in ST's application notes for multi-phase buck designs.

What compensation topology is recommended for ceramic-output-capacitor designs?

For low-ESR ceramic output capacitors, ST recommends a Type II compensation network (one pole, one zero) connected between COMP and FB. This provides adequate phase margin with minimal components, as the capacitor's ESR zero naturally compensates the LC double-pole - detailed in Section 6.4.2 of the official datasheet.

L5986ATR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

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

Packaging:: Tape & Reel (TR)

Product Status:: Active

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 1

Voltage - Input (Min):: 2.9V

Voltage - Input (Max):: 18V

Voltage - Output (Min/Fixed):: 0.6V

Voltage - Output (Max):: 18V

Current - Output:: 2.5A

Frequency - Switching:: 250kHz ~ 1MHz

Synchronous Rectifier:: No

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-HSOP

L5986ATR FAQ

1.How can I place an order for L5986ATR through Aetrix?

Please submit a Request for Quotation (RFQ) for L5986ATR 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 L5986ATR reliable?

The price and inventory of L5986ATR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L5986ATR is usually 5 days.

3.What payment methods are accepted for L5986ATR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L5986ATR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L5986ATR?

L5986ATR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L5986ATR 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 L5986ATR?

For technical support, including L5986ATR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L5986ATR requirements.

6.How does Aetrix verify that L5986ATR is sourced from the original manufacturer or authorized distributors?

All L5986ATR 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 L5986ATR meets industry standards.

7.What is the process for return or replacement of L5986ATR?

All L5986ATR units undergo pre-shipment inspection (PSI). If there is an issue with L5986ATR, 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 L5986ATR part is unused and in its original packaging.

Return procedure for L5986ATR:

1.Submit a request within 90 days.

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

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