Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

STMicroelectronics L6986ITR

Name: L6986ITR
Brand: STMicroelectronics
SKU: L6986ITR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: L6986ITR

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 16-PowerTSSOP (0.173", 4.40mm Width)

Datasheet:: L6986ITR.pdf

Description:: IC REG BUCK ADJ 16HTSSOP

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:1,862

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

L6986ITR from STMicroelectronics is a synchronous isolated buck (iso-buck) DC-DC converter IC designed for primary-side regulation in transformer-coupled isolated power supplies. It integrates P-channel high-side and N-channel low-side MOSFETs (R_DS(on) = 180 mΩ / 150 mΩ), operates from 4 V to 38 V input, delivers up to 1.9 A peak sink current, and supports forced PWM with 300 ns current-sense blanking - enabling robust energy transfer to secondary windings for SiC/IGBT gate drivers and isolated interfaces.

For engineers reviewing the L6986ITR datasheet, L6986ITR pinout, L6986ITR application, or L6986ITR equivalent, this device is selected for its optocoupler-free primary voltage regulation, adjustable soft-start with tracked secondary ramp-up, embedded overvoltage protection, and synchronization-capable switching frequency (250–1000 kHz) - critical for EV charger auxiliary supplies, motor drive isolation, and industrial UPS systems.

Technical Context

The L6986ITR implements a peak current mode control architecture with fixed-frequency forced PWM operation, enabling precise primary output regulation without optocouplers by leveraging transformer turns ratio for secondary voltage derivation. Its P-channel high-side switch enables 100% duty cycle capability, while pulse-by-pulse current sensing on both MOSFETs provides primary-side constant-current protection and secondary short-circuit immunity via reverse current limiting.

Internal blocks include a transconductance error amplifier (100 dB gain, 0.85 V reference), programmable slope compensation, switchover regulator (VBIAS-supported quiescent current reduction), and an open-drain RST output with adjustable delay and threshold strapping (via MLF pin resistor). The 300 ns blanking time suppresses leakage-inductance-induced oscillations at LX, ensuring stable current sensing across wide input and load ranges.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	4 V to 38 V - supports wide industrial and automotive battery inputs including 12 V, 24 V, and 36 V nominal rails.
Peak Primary Sink Current	1.9 A typical - ensures sufficient energy transfer during soft-start and heavy-load transients to maintain regulated secondary output.
Switching Frequency	250 kHz to 1000 kHz, selectable via FSW pin strapping - balances EMI, efficiency, and transformer size for compact isolated designs.
R_DS(on) HS / LS	180 mΩ / 150 mΩ - reduces conduction losses in primary-side synchronous rectification, improving full-load efficiency.
Quiescent Current (Shutdown)	8 µA typical - minimizes standby power in always-on isolated bias supplies for gate drivers and communication interfaces.
Soft-Start Time	Adjustable via external capacitor on SS/INH - controls inrush current and enables tracked ramp-up of secondary output voltage.
Overvoltage Protection	1.2× V_REF (±5%) trip with hysteresis - discharges output capacitor to prevent damage during regulation failure or transformer saturation.

Pinout & Package

HTSSOP16 package (exposed pad connected to SGND+PGND); thermal resistance R_thJA = 40 °C/W on ST demo board.

Pin/Terminal	Circuit Role	Design Meaning
RST	Open-collector reset output	Asserts low when primary output voltage falls out of regulation; delay and threshold configurable via external components.
VCC	Internal analog supply	Supplies internal circuitry; requires ≥470 nF ceramic capacitor for stable bandgap reference and error amplifier operation.
SS/INH	Soft-start / inhibit control	Charged by internal 4 µA current source for soft-start; pulled low to disable device - dual-function pin with hysteresis.
FSW	Frequency selection	Strapped to VCC or GND with E24 resistors to set f_SW before soft-start; enables master/slave sync in slave mode.
FB	Primary output voltage feedback	Connects to resistive divider from primary output; referenced to 0.85 V internal error amplifier threshold.
LX	Switching node	Drives transformer primary winding; dual pins (13 & 14) reduce parasitic inductance and improve layout for high di/dt switching.
PGND / SGND	Power / signal ground	Separate PGND (pins 11,12) and SGND (pin 10) minimize noise coupling into sensitive analog blocks like COMP and FB.
VBIAS	Switchover supply input	Accepts 3–5.5 V external regulated voltage (e.g., primary output) to reduce VIN quiescent current by ~50%.

Key Features

Feature	Design Value
Optocoupler-free regulation	Primary-side voltage control eliminates optocoupler latency, aging, and CMTI limitations - simplifies BOM and improves long-term stability.
Tracked secondary soft-start	Forced PWM operation during soft-start enables simultaneous, proportional ramp-up of primary and secondary outputs - prevents secondary overvoltage at startup.
Programmable RST supervision	MLF pin resistor selects RST threshold (80–96% of V_OUT); DELAY capacitor sets release timing - enables flexible power-good sequencing.
Leakage-inductance tolerant sensing	300 ns blanking window + slope compensation rejects transformer ringing - ensures reliable current-mode control without snubber dependency.
Synchronization-ready architecture	SYNCH pin supports daisy-chained master/slave operation up to 6 devices - enables phase interleaving and EMI reduction in multi-rail isolated systems.

Applications

SiC/IGBT Gate Driver Supply

Isolated Communication Interface

Use Scenario: Providing isolated ±15 V bias to high-speed SiC MOSFET gate drivers in traction inverters.

IC Role / Device Role / Timing Role: Primary-side regulated iso-buck controller generating stable 15 V primary output, with transformer-coupled secondary delivering gate drive voltage.

Use Value: Eliminates optocoupler-based feedback, reducing propagation delay and improving CMTI (>100 kV/µs), while 1.9 A sink current ensures fast gate charging under transient loads.

Use Scenario: Powering isolated RS-485 or SPI isolators in factory automation PLC I/O modules.

IC Role / Device Role / Timing Role: Compact isolated DC-DC source delivering 3.3 V or 5 V to secondary-side digital isolators and level shifters.

Use Value: Adjustable f_SW avoids noise overlap with data rates; 8 µA shutdown current extends system sleep mode duration without compromising wake-up response.

EV Onboard Charger Auxiliary Rail

Industrial UPS Hold-Up Supply

Use Scenario: Generating isolated 12 V bias for microcontrollers and sensors in bidirectional AC/DC converters.

IC Role / Device Role / Timing Role: Regulated primary output powers MCU and ADC; secondary side supplies isolated CAN transceivers and current sense amplifiers.

Use Value: 4–38 V input range accommodates wide battery voltage swings (e.g., 24 V–48 V systems); OVP and thermal shutdown ensure safety during grid fault conditions.

Use Scenario: Delivering isolated 5 V standby power to control logic during mains failure in line-interactive UPS units.

IC Role / Device Role / Timing Role: Maintains regulation during brownouts using hold-up capacitors on VIN; RST output signals loss of primary regulation to system supervisor.

Use Value: 100% duty cycle capability sustains output down to 4 V input; programmable DELAY allows timed graceful shutdown before backup battery depletion.

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated buck controller applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
UCC28911DR	Primary-side flyback controller with integrated 700 V MOSFET; no synchronous rectification; requires optocoupler for tight regulation.	Better suited for lower-power (<2 W), cost-sensitive flyback topologies; lacks iso-buck's transformer utilization efficiency and secondary tracking.	Select UCC28911DR only when input >40 V or when transformer design favors flyback over iso-buck for simplicity.
MAX13256ATL+	Half-bridge gate driver with integrated oscillator; no regulation loop, no FB pin, no OVP - requires external error amp and feedback.	Used in resonant or self-oscillating isolated supplies; demands full external control loop design and adds component count.	Choose MAX13256ATL+ only for custom resonant LLC or push-pull topologies where fixed-frequency PWM regulation is not required.

Compared with UCC28911DR and MAX13256ATL+, the L6986ITR uniquely integrates synchronous switching, optocoupler-free regulation, and tracked soft-start - making it optimal for medium-power (up to 5 W) iso-buck designs requiring high reliability, low EMI, and minimal external components.

Availability

L6986ITR is available at Aetrix Electronics and suitable for EV chargers, motor drivers, and industrial UPS systems requiring stable component supply, long lifecycle support, and guaranteed traceable sourcing for safety-critical power rails.

Supply support for L6986ITR 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, specializing in power management, automotive ICs, and industrial control solutions with broad manufacturing scale and AEC-Q100 qualification capabilities.

The L6986I belongs to ST's high-reliability isolated power controller product line, engineered specifically for transformer-coupled DC-DC conversion in safety-isolated systems - targeting gate drivers, industrial communications, and energy infrastructure where regulation accuracy and fault resilience are critical.

FAQ

What is the purpose of the VBIAS pin on the L6986ITR?

The VBIAS pin enables switchover of the internal regulator's supply source from VIN to an external 3–5.5 V voltage (typically the regulated primary output). When active, it reduces total quiescent current drawn from VIN by ~50%, improving light-load efficiency in always-on isolated bias rails used for gate drivers and interface ICs.

How does the L6986ITR achieve optocoupler-free regulation?

The L6986ITR regulates the primary-side output voltage directly using the FB pin and internal 0.85 V reference. The secondary output voltage is derived solely from the transformer turns ratio and remains tightly coupled to the primary output - eliminating need for optocoupler feedback while maintaining ±2% typical line/load regulation on the primary rail.

Can the L6986ITR drive a center-tapped transformer configuration?

No - the L6986ITR is designed exclusively for two-winding transformer topologies in iso-buck configuration. Its internal synchronous switches and control logic assume single primary winding with polarity-defined energy transfer; center-tapped or push-pull configurations require external gate drivers and separate control schemes not supported by this IC.

What is the minimum recommended CSS value for soft-start, and why?

The minimum CSS is not specified; however, ST recommends CSS ≤ 67 nF to ensure complete discharge within 1 ms using the internal 0.6 mA discharge current during fault recovery. Larger values risk incomplete discharge after UVLO or thermal shutdown, causing inconsistent soft-start behavior and potential secondary overvoltage at next power-up.

L6986ITR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 16-PowerTSSOP (0.173", 4.40mm Width)

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):: 4V

Voltage - Input (Max):: 38V

Voltage - Output (Min/Fixed):: 0.85V

Voltage - Output (Max):: 38V

Current - Output:: -

Frequency - Switching:: 275kHz ~ 2.2MHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 16-HTSSOP

L6986ITR FAQ

1.How can I place an order for L6986ITR through Aetrix?

Please submit a Request for Quotation (RFQ) for L6986ITR 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 L6986ITR reliable?

The price and inventory of L6986ITR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L6986ITR is usually 5 days.

3.What payment methods are accepted for L6986ITR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L6986ITR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L6986ITR?

L6986ITR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L6986ITR 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 L6986ITR?

For technical support, including L6986ITR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L6986ITR requirements.

6.How does Aetrix verify that L6986ITR is sourced from the original manufacturer or authorized distributors?

All L6986ITR 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 L6986ITR meets industry standards.

7.What is the process for return or replacement of L6986ITR?

All L6986ITR units undergo pre-shipment inspection (PSI). If there is an issue with L6986ITR, 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 L6986ITR part is unused and in its original packaging.

Return procedure for L6986ITR:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-03 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-01 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…