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 L6984ATR

Name: L6984ATR
Brand: STMicroelectronics
SKU: L6984ATR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: L6984ATR

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 10-VFDFN Exposed Pad

Datasheet:: L6984ATR.pdf

Description:: IC REG BCK ADJ/0.9V 0.4A 10VDFPN

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:5,927

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

Product details

Overview

L6984ATR from STMicroelectronics is a 36 V, 400 mA synchronous step-down switching regulator with constant-on-time (COT) control, integrated high- and low-side MOSFETs, and dual operating modes (LCM/LNM). It delivers 0.9–3.3 V adjustable output (fixed 3.3 V without external divider), supports 4.5–36 V input, achieves 75 µA quiescent current in LCM at light load, and features PGOOD open-collector output for power sequencing - used in automotive parking-mode battery systems and precision sensor power rails.

For engineers reviewing the L6984ATR datasheet, L6984ATR pinout, L6984ATR application, or L6984ATR equivalent, key selection criteria include its 250–600 kHz adjustable switching frequency, valley current limit of 350 mA, VBIAS-assisted light-load efficiency optimization, thermal shutdown at 150 °C, and VFDFPN10 4 × 4 × 1.0 mm package compatibility with compact industrial and automotive PCB layouts.

Technical Context

The L6984ATR implements a constant-on-time (COT) control architecture with VIN feed-forward correction, enabling fast transient response and near-constant fSW across 4.5–36 V input. Its TON generator uses an external resistor (RTON) between VIN and TON pins to set switching frequency from 250 kHz to 600 kHz, with internal compensation for input voltage variation.

Two selectable light-load modes are implemented via the LNM pin: Low Noise Mode (LNM) uses fixed-frequency PWM to minimize output ripple for audio/sensor applications; Low Consumption Mode (LCM) employs pulse-skipping to achieve 75 µA IQ at 3.3 V output. The switchover regulator routes bias current from VBIAS (typically connected to VOUT) to maximize efficiency below 100 mA load.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	4.5 V to 36 V - supports wide-range automotive battery (cold-crank to load-dump) and industrial DC bus inputs.
Output Current	400 mA DC - sufficient for powering microcontrollers, sensors, and RF modules in space-constrained designs.
Quiescent Current (LCM)	75 µA at 3.3 V VOUT - enables multi-year battery life in always-on parking-mode automotive electronics.
Switching Frequency	Adjustable 250–600 kHz - balances EMI control, inductor size, and efficiency; set via RTON resistor on TON pin.
Output Voltage Range	0.9 V to 3.3 V (adjustable); fixed 3.3 V requires no external resistor divider - simplifies BOM and layout for standard logic rail.
Valley Current Limit	350 mA - provides robust short-circuit and overload protection using pulse-by-pulse low-side sensing.
PGOOD Output	Open-collector, active-low - enables precise power-rail sequencing and system-level fault detection during startup.

Pinout & Package

Package: VFDFPN10 (4 mm × 4 mm × 1.0 mm), wettable flank, RoHS-compliant, thermally enhanced exposed pad.

Pin/Terminal	Circuit Role	Design Meaning
1 - PGOOD	Power Good status indicator	Open-drain output pulled low when FB voltage drops below 84–92% of target - used for MCU reset assertion or downstream enable sequencing.
2 - FB	Inverting input of error amplifier	Connects to voltage divider (or directly to VCC for fixed 3.3 V); references internal 0.9 V bandgap - sets output regulation point.
3 - TON	Frequency setting node	External resistor (RTON) from VIN sets switching frequency; parasitic capacitance affects accuracy - requires board-specific calibration.
4 - EN	Enable control input	Active-high logic; threshold 2.6 V - allows direct connection to microcontroller GPIO or system power rail for controlled startup/shutdown.
5 - GND	Power ground reference	Common return for power switches, control circuitry, and thermal pad - must be low-impedance plane under exposed pad.
6 - LX	Switching node	Drives external inductor; connects internally to high- and low-side MOSFETs - requires tight layout to minimize EMI and voltage spikes.
7 - VIN	Main power input	Accepts 4.5–36 V; supplies internal controller and high-side switch - requires local 10 µF ceramic + bulk capacitor for stability.
8 - VCC	Internal LDO output	3.3 V regulated supply for control circuitry; requires 1 µF ceramic capacitor - powers internal logic when VBIAS < 2.4 V.
9 - VBIAS	Bias supply input	Connected to VOUT to power analog blocks from regulated rail - reduces IQ by bypassing VCC LDO, improving light-load efficiency.
10 - LNM	Mode selection strap	Tied to VCC for Low Noise Mode (constant fSW); tied to GND for Low Consumption Mode (pulse-skipping) - configures core operating behavior at power-up.

Key Features

Feature	Design Value
Synchronous rectification	Integrated high- and low-side MOSFETs eliminate external diode - improves full-load efficiency by >15% vs. asynchronous designs.
VBIAS-assisted biasing	Draws quiescent current from regulated output instead of VIN - reduces light-load IQ from 230 µA (VBIAS = GND) to 75 µA (VBIAS = VOUT).
Constant-on-time (COT) control	No external compensation required - enables stable operation with low-ESR ceramic output capacitors and fast load-step response (<10 µs).
Dual light-load modes	Hardware-strapped LNM (low noise) or LCM (low consumption) - eliminates software configuration and ensures deterministic behavior at startup.
Thermal shutdown with hysteresis	Triggers at 150 °C, releases at 130 °C - prevents thermal runaway during sustained overload or poor heatsinking.

Applications

Automotive Parking Systems

Industrial Sensor Nodes

Use Scenario: Always-on vehicle monitoring during extended parking (e.g., intrusion detection, tire pressure telemetry).

IC Role / Device Role / Timing Role: Primary 3.3 V power regulator for ultra-low-power MCU and RF transceiver, operating in Low Consumption Mode (LCM).

Use Value: 75 µA IQ extends 12 V lead-acid battery life beyond 3 years without recharge - avoids parasitic drain-induced battery failure.

Use Scenario: Remote environmental sensor (temperature/humidity/CO₂) powered by Li-SOCl₂ battery in unattended field deployment.

IC Role / Device Role / Timing Role: Step-down regulator delivering stable 3.3 V to precision ADC and BLE SoC, configured for LCM to minimize standby current.

Use Value: Enables >10-year operational lifetime on single primary cell - validated at -40 °C to +125 °C ambient.

Automotive Audio Subsystems

Smart Meter Power Rails

Use Scenario: Powering DSP, DAC, and analog front-end in infotainment head units where EMI-sensitive audio signals coexist with switching regulators.

IC Role / Device Role / Timing Role: 3.3 V/2.5 V auxiliary rail generator in Low Noise Mode (LNM), with fixed 500 kHz fSW and minimized output ripple.

Use Value: Achieves <10 mVpp output ripple across 1–400 mA load - prevents audible switching artifacts in Class-D amplifier stages.

Use Scenario: Providing isolated 3.3 V rail for metrology ASIC and real-time clock in ANSI C12.22-compliant smart electricity meters.

IC Role / Device Role / Timing Role: Main DC-DC converter for meter's microcontroller and communication module, leveraging PGOOD for secure boot sequence validation.

Use Value: PGOOD signal synchronizes firmware initialization only after stable VOUT - prevents corrupted flash writes during brown-out conditions.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TPS62840DRVR	Lower IQ (300 nA in shutdown, 60 nA in LP mode), but max 3 A input voltage (6 V) - not suitable for 36 V automotive input.	Targeted at ultra-low-power portable devices (wearables), not automotive or industrial 12–36 V systems.	Select only if input voltage ≤6 V and sub-µA shutdown is critical; incompatible with L6984ATR's 36 V rating and thermal robustness.
MP2451DT-LF-Z	400 mA output, 36 V input, but asynchronous (external diode), higher IQ (260 µA), no LCM/LNM mode selection.	Lacks VBIAS optimization and dual-mode flexibility - less efficient at light load and no low-noise option for sensitive analog rails.	Choose for cost-sensitive, non-automotive 36 V applications where 75 µA IQ and ripple control are not required.

Compared with TPS62840DRVR and MP2451DT-LF-Z, the L6984ATR uniquely combines 36 V input tolerance, 75 µA light-load IQ, hardware-selectable LCM/LNM modes, and synchronous integration - making it optimal for automotive and industrial battery-powered systems demanding both efficiency and noise control.

Availability

L6984ATR is available at Aetrix Electronics and suitable for automotive parking systems, industrial sensor nodes, automotive audio subsystems, and smart meter power rails requiring stable component supply, long-lifecycle support, and AEC-Q100-aligned reliability.

Supply support for L6984ATR 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 analog, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

The L6984ATR belongs to ST's high-voltage monolithic DC-DC regulator product line, engineered specifically for automotive and industrial applications requiring wide-input operation, ultra-low quiescent current, and robust thermal performance in compact packages.

FAQ

What is the recommended layout practice for the TON pin to ensure accurate switching frequency?

Place the RTON resistor as close as possible to the TON pin (Pin 3) with minimal trace length and no vias. Avoid routing near noisy signals (e.g., LX, VIN). For production accuracy, measure actual fSW with oscilloscope and fine-tune RTON value - typical parasitic capacitance (CINT + CPAR) is ~7.5 pF on ST's evaluation board, but varies with layout.

How does VBIAS connection affect efficiency across load conditions?

When VBIAS is connected to VOUT, the internal LDO is disabled and bias current is sourced from the regulated rail, reducing IQ from 230 µA (VBIAS = GND) to 75 µA at light load. At full load, VBIAS has negligible impact on efficiency since main power flows through the synchronous switches - the benefit is exclusively in sub-100 mA operation.

Can the L6984ATR safely operate with ceramic output capacitors only?

Yes - its COT control loop is explicitly designed for low-ESR ceramic capacitors. Unlike traditional COT regulators, it does not require minimum ESR for stability. Use ≥10 µF X7R/X5R ceramics with appropriate voltage rating; ST recommends 22 µF for 3.3 V output per the evaluation board design.

What is the function of the PGOOD signal during power-up sequencing?

PGOOD asserts high (open-drain pulled up externally) only after VOUT reaches 90% of target and remains stable for >100 µs. This enables safe sequencing - e.g., holding MCU reset until power is valid, or enabling downstream regulators in cascade. Its 4 mA sink capability supports direct interface with most logic-level inputs without buffering.

L6984ATR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 10-VFDFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Active

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable (Fixed)

Number of Outputs:: 1

Voltage - Input (Min):: 4.5V

Voltage - Input (Max):: 36V

Voltage - Output (Min/Fixed):: 0.9V (3.3V)

Voltage - Output (Max):: 28V

Current - Output:: 400mA

Frequency - Switching:: 250kHz ~ 600kHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 10-VDFPN (3x3)

L6984ATR FAQ

1.How can I place an order for L6984ATR through Aetrix?

Please submit a Request for Quotation (RFQ) for L6984ATR 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 L6984ATR reliable?

The price and inventory of L6984ATR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L6984ATR is usually 5 days.

3.What payment methods are accepted for L6984ATR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L6984ATR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L6984ATR?

L6984ATR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L6984ATR 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 L6984ATR?

For technical support, including L6984ATR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L6984ATR requirements.

6.How does Aetrix verify that L6984ATR is sourced from the original manufacturer or authorized distributors?

All L6984ATR 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 L6984ATR meets industry standards.

7.What is the process for return or replacement of L6984ATR?

All L6984ATR units undergo pre-shipment inspection (PSI). If there is an issue with L6984ATR, 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 L6984ATR part is unused and in its original packaging.

Return procedure for L6984ATR:

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…