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 L6983CQTR

Name: L6983CQTR
Brand: STMicroelectronics
SKU: L6983CQTR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: L6983CQTR

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 16-WFQFN Exposed Pad

Datasheet:: L6983CQTR.pdf

Description:: IC REG BUCK ADJ 3A 16QFN

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:425

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

Product details

Overview

L6983CQTR from STMicroelectronics is a synchronous monolithic step-down DC-DC converter delivering up to 3 A output current with 3.5 V to 38 V input range, 0.85 V to VIN adjustable output, and 17 µA quiescent current in LCM mode. It integrates peak current mode control, internal compensation, and dual operating modes (LCM for light-load efficiency, LNM for low-noise fixed-frequency operation), targeting industrial 24 V bus power systems and always-on sensor nodes.

For engineers reviewing the L6983CQTR datasheet, L6983CQTR pinout, L6983CQTR application, or L6983CQTR equivalent, key selection criteria include programmable 200 kHz–2.3 MHz switching frequency, integrated Power Good and enable functionality, QFN16 3×3 mm package with exposed thermal pad, and verified soft-start (1.3 ms), overvoltage protection (120% VREF), and thermal shutdown (165 °C).

Technical Context

The L6983CQTR implements peak current mode control with slope compensation to prevent subharmonic oscillation, supporting both forced PWM (LNM) and pulse-skipping (LCM) light-load strategies. Its embedded transconductance error amplifier features an integrated compensation network, eliminating external components.

It provides dual supply paths via VBIAS switchover-reducing input quiescent current when VBIAS is connected to regulated output-and supports synchronization (LNM only) and spread-spectrum dithering (±5% FSW) for EMC optimization. The device includes pulse-by-pulse high-side/low-side current sensing and thermal foldback protection.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	3.5 V to 38 V - supports direct connection to 24 V industrial buses and wide-range battery inputs without pre-regulation.
Output Current	3 A DC - sufficient for powering microcontrollers, sensors, and I/O peripherals in decentralized nodes.
Quiescent Current (LCM)	17 µA from VIN at VBIAS = GND - enables multi-year battery life in always-on sensor applications.
Switching Frequency	200 kHz to 2.3 MHz programmable - allows optimization of size (high FSW) vs. efficiency (low FSW) and EMI compliance.
Feedback Reference	0.85 V ±0.5% - enables precise output regulation across temperature (−40 °C to +125 °C) with minimal drift.
Thermal Shutdown	165 °C with 30 °C hysteresis - prevents thermal runaway while allowing safe recovery after transient overload.
Power Good Threshold	90% of VOUT with 3% hysteresis - provides reliable system reset signaling without external monitoring circuitry.
Enable Threshold	1.2 V rising, 1.0 V falling - ensures clean, noise-immune startup/shutdown sequencing in noisy industrial environments.

Pinout & Package

Package: QFN16 (3 mm × 3 mm, 0.5 mm pitch) with exposed thermal pad (E.P.) requiring connection to both AGND and PGND for optimal thermal performance and EMI suppression.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 12 VIN	Primary input voltage rail	Dual VIN pins reduce trace resistance and improve current sharing; connects directly to bulk input capacitor.
3, 10 AGND	Analog ground reference	Separate analog ground plane minimizes noise coupling into feedback and error amplifier circuits.
4 EN/CLKIN	Enable input / external clock sync	Enables device startup (1.2 V threshold); in LNM versions, accepts 200–2200 kHz external clock for EMI reduction.
5 PGOOD	Open-drain power-good indicator	Signals valid output regulation; requires external pull-up for MCU reset or sequencing logic.
6 VBIAS	Bias supply input	Accepts external 3–VIN voltage to reduce input quiescent current; connect to AGND if unused.
7 FB/VOUT	Feedback input / fixed-output sense	In adjustable versions: senses divider ratio; in fixed versions (3.3 V/5 V): internal resistor network sets output.
8 FSW	Frequency programming node	Resistor-to-VCC or resistor-to-GND selects switching frequency and enables optional spread spectrum dithering.
9 VCC	Internal LDO output	Supplies internal analog circuitry; requires ≥1 µF ceramic bypass capacitor for stable reference generation.
11 BOOT	High-side gate driver bootstrap	Connects 100 nF capacitor to SW to generate gate drive voltage above VIN for NMOS high-side switch.
13, 16 PGND	Power ground return	Low-inductance path for high-current switching loops; must be separated from AGND except at single-point E.P. tie.
14, 15 SW	Switching node	Drives external inductor; high di/dt node requiring tight layout and minimized loop area to reduce EMI.
E.P.	Exposed thermal pad	Mandatory connection to both AGND and PGND planes for thermal dissipation (R_thJA = 30 °C/W) and EMI shielding.

Key Features

Feature	Design Value
Integrated compensation network	Eliminates external Type-II/III compensation components, reducing BOM count and design iteration time.
Programmable soft-start (1.3 ms)	Controls inrush current during power-up, preventing input rail collapse and downstream reset glitches.
Two light-load modes (LCM/LNM)	LCM achieves >85% efficiency at 1 mA load; LNM maintains constant 2.3 MHz switching for <10 mV_pp ripple in noise-sensitive ADCs.
Overvoltage protection (120% VREF)	Actively discharges output capacitor on fault, protecting downstream 3.3 V/5 V logic from overvoltage damage.
Synchronization input (LNM only)	Allows alignment of switching edges across multiple rails to avoid beat frequencies and simplify EMI filtering.
Spread-spectrum dithering (±5%)	Reduces peak radiated emissions by spreading energy across a 100 kHz bandwidth, easing CISPR 22/32 compliance.

Applications

Industrial 24 V Bus Power

Always-On Sensor Nodes

Use Scenario: Powering PLC I/O modules, fieldbus gateways, and motor drivers from unregulated 24 V DC rails with wide input variation.

IC Role / Device Role / Timing Role: Primary non-isolated buck regulator providing stable 5 V or 3.3 V for microcontrollers, CAN transceivers, and analog front-ends.

Use Value: 38 V max input withstands 40 V load-dump transients; 3 A output supports multiple peripherals without external boost stages.

Use Scenario: Battery-powered environmental sensors (temperature, humidity, gas) transmitting data periodically via LoRaWAN or NB-IoT.

IC Role / Device Role / Timing Role: Ultra-low-quiescent buck converter maintaining system readiness during multi-second sleep cycles.

Use Value: 17 µA LCM quiescent current extends 2×AA battery life beyond 5 years; internal soft-start prevents wake-up current spikes.

Decentralized Intelligent Nodes

Low-Noise Analog Signal Chains

Use Scenario: Edge AI inference nodes in factory automation using microcontrollers with integrated ML accelerators and local memory.

IC Role / Device Role / Timing Role: Point-of-load regulator supplying 1.2 V core and 3.3 V I/O rails with independent sequencing and Power Good handshaking.

Use Value: Output voltage sequencing ensures proper power-up order; PGOOD enables firmware-controlled initialization timing.

Use Scenario: High-resolution industrial ADCs (e.g., 24-bit sigma-delta) and precision op-amp signal conditioning in weigh scales or medical monitors.

IC Role / Device Role / Timing Role: Low-noise LNM-mode buck supplying clean 5 V reference and analog supply with <10 µV_RMS noise floor.

Use Value: Constant-frequency PWM and minimized output ripple (<5 mV_pp) preserve SNR; synchronization avoids mixing artifacts.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM61480RGER	4.5–36 V input, 8 A output, 15 µA IQ, no internal compensation, requires external loop compensation.	Higher current capability but larger solution size; lacks integrated soft-start and VBIAS switchover.	Prefer for high-current (>4 A), cost-sensitive designs where board space permits external compensation.
TPS6286413ARQYR	2.7–6 V input, 4 A output, 2.5 µA IQ, fixed 3.3 V/5 V only, no programmable FSW or sync input.	Optimized for USB-powered or low-voltage battery systems; incompatible with 24 V industrial inputs.	Prefer only for sub-6 V portable applications requiring ultra-low IQ and minimal external components.

Compared with LM61480RGER and TPS6286413ARQYR, the L6983CQTR uniquely combines wide 3.5–38 V input, integrated compensation, dual LCM/LNM modes, and industrial-grade protection - making it the only drop-in fit for 24 V bus systems needing both efficiency and noise control in one compact QFN16 package.

Availability

L6983CQTR is available at Aetrix Electronics and suitable for industrial automation, battery-powered IoT sensors, and decentralized edge computing nodes requiring stable component supply across extended product lifecycles.

Supply support for L6983CQTR 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 silicon solutions for automotive, industrial, and power management applications.

The L6983 series belongs to ST's high-reliability industrial DC-DC converter portfolio, engineered specifically for robust operation in harsh 24 V industrial environments with emphasis on low IQ, wide VIN, and integrated protection features.

FAQ

What is the difference between L6983CQTR and L6983IQTR?

The L6983CQTR is the LCM (Low Consumption Mode) variant optimized for ultra-low quiescent current (17 µA), while the L6983IQTR is the LNM (Low Noise Mode) version featuring forced PWM operation and external clock synchronization. Both share identical pinout, package, and maximum ratings-but differ in light-load behavior, IQ, and noise profile. Selection depends on whether battery life (LCM) or signal integrity (LNM) is prioritized.

Can L6983CQTR operate with a 40 V input transient?

Yes - the absolute maximum input voltage rating is 42 V per datasheet Table 3, and the device includes overvoltage protection that actively discharges the output capacitor if VOUT exceeds 120% of the feedback reference. This makes it suitable for 24 V industrial systems subject to ISO 16750-2 load-dump transients up to 40 V, provided input capacitance and layout meet ST's recommended guidelines.

How is thermal performance affected by the exposed pad connection?

The exposed thermal pad (E.P.) must be soldered to a PCB copper area connected to both AGND and PGND planes. Per datasheet Table 5, this achieves R_thJA = 30 °C/W on ST's demo board. Omitting the E.P. connection or isolating it increases junction-to-ambient thermal resistance by >40%, risking thermal shutdown at ≤2 A continuous load. Minimum recommended copper area is 120 mm² with ≥4 thermal vias.

Does L6983CQTR support output voltage sequencing with other regulators?

Yes - the EN pin supports precise power-up sequencing via external RC networks or dedicated sequencer ICs, and the open-drain PGOOD output can drive the EN pin of downstream regulators. When used with fixed-output variants (e.g., 3.3 V or 5 V), sequencing is achieved by delaying EN assertion until upstream rails stabilize; adjustable versions allow fine-tuning via external feedback dividers to match required ramp rates.

L6983CQTR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 16-WFQFN 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):: 3.5V

Voltage - Input (Max):: 38V

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

Voltage - Output (Max):: 38V

Current - Output:: 3A

Frequency - Switching:: 200kHz ~ 2.2MHz

Synchronous Rectifier:: Yes

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 16-QFN (3x3)

L6983CQTR FAQ

1.How can I place an order for L6983CQTR through Aetrix?

Please submit a Request for Quotation (RFQ) for L6983CQTR 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 L6983CQTR reliable?

The price and inventory of L6983CQTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L6983CQTR is usually 5 days.

3.What payment methods are accepted for L6983CQTR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L6983CQTR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L6983CQTR?

L6983CQTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L6983CQTR 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 L6983CQTR?

For technical support, including L6983CQTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L6983CQTR requirements.

6.How does Aetrix verify that L6983CQTR is sourced from the original manufacturer or authorized distributors?

All L6983CQTR 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 L6983CQTR meets industry standards.

7.What is the process for return or replacement of L6983CQTR?

All L6983CQTR units undergo pre-shipment inspection (PSI). If there is an issue with L6983CQTR, 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 L6983CQTR part is unused and in its original packaging.

Return procedure for L6983CQTR:

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…