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

STMicroelectronics L6983C50QTR

Name: L6983C50QTR
Brand: STMicroelectronics
SKU: L6983C50QTR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L6983C50QTR

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 16-WFQFN Exposed Pad

Datasheet:: L6983C50QTR.pdf

Description:: IC REG BUCK 5V 3A 16QFN

Quantity:: RFQ Add To RFQ list

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Product details

Overview

L6983C50QTR from STMicroelectronics is a synchronous monolithic step-down DC-DC converter delivering up to 3 A output current with 17 μA quiescent current, 3.5–38 V input range, and fixed 5.0 V output. It employs peak current mode control in QFN16 (3×3 mm) package with internal compensation, supporting industrial 24 V bus systems and always-on sensor nodes.

For engineers reviewing the L6983C50QTR datasheet, L6983C50QTR pinout, L6983C50QTR application, or L6983C50QTR equivalent, key selection criteria include light-load efficiency mode (LCM/LNM), programmable 200 kHz–2.3 MHz switching frequency, integrated Power Good signal, and VIN-compatible enable/shutdown functionality with 2 μA shutdown current.

Technical Context

The L6983C50QTR implements a peak current mode architecture with constant-frequency PWM control in LNM mode or pulse-skipping in LCM mode. Its internal transconductance error amplifier features fully integrated compensation, eliminating external components while maintaining stability with low-ESR ceramic output capacitors.

It integrates dual power switches (RDSON_HS = 0.130 Ω, RDSON_LS = 0.085 Ω), pulse-by-pulse overcurrent protection, thermal shutdown at 165 °C, and overvoltage protection triggering at 115–125% of nominal output. The EN/CLKIN pin serves as enable input (1.2 V threshold) and external clock sync interface for LNM variants.

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 Voltage	Fixed 5.0 V ±1% - internally trimmed feedback divider eliminates external resistor network; VFB = 5.0 V × (R_FBL/(R_FBH+R_FBL)) = 0.85 V reference.
Max Output Current	3 A DC - sustained delivery enabled by integrated 0.130 Ω HS / 0.085 Ω LS MOSFETs and thermal design with R_{th_JA} = 30 °C/W.
Quiescent Current	17 μA typical - enables multi-year operation in battery-powered always-on sensors without compromising regulation accuracy.
Switching Frequency	200 kHz to 2.3 MHz programmable via FSW pin resistor - allows EMI optimization and inductor size reduction while supporting spread spectrum dithering (±5%).
Protection Features	Overvoltage (115–125%), thermal shutdown (165 °C), pulse-by-pulse current limit (4.1–4.6 A peak), and PGOOD open-drain monitoring - ensures robust system-level fault handling.
Enable Function	EN pin with 1.2 V rising threshold and 0.2 V hysteresis - provides clean startup sequencing and <2 μA shutdown current when pulled low.

Pinout & Package

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

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 12 VIN	Power Input	High-current input connections for 3.5–38 V supply; pins 1/2/12 share VIN node to reduce trace inductance and improve transient response.
3, 10 AGND	Analog Ground	Reference ground for error amplifier, FB, VBIAS, and EN circuits; must be star-connected to exposed pad to minimize noise coupling.
4 EN/CLKIN	Enable & Clock Input	Dual-function pin: digital enable (1.2 V threshold) for LCM/LNM; external clock sync input (200–2200 kHz) for LNM only.
5 PGOOD	Power Good Monitor	Open-drain output asserting low when VOUT drops below 90% of nominal; requires external pull-up for system power sequencing.
6 VBIAS	Bias Supply Input	Optional auxiliary supply (3–VIN) to reduce input quiescent current; connected to VOUT in self-biased configurations.
7 FB/VOUT	Feedback / Output Sense	Fixed 5 V version uses internal divider; pin senses regulated output and feeds error amplifier reference (0.85 V).
8 FSW	Frequency Set	Resistor-to-VCC or GND sets switching frequency (200 kHz–2.3 MHz); enables optional spread spectrum dithering.
9 VCC	Internal LDO Output	3.3 V ±10% analog supply for internal circuitry; requires ≥1 µF ceramic capacitor to AGND for stability.
11 BOOT	Bootstrap Gate Drive	Connects 100 nF capacitor to SW to generate gate voltage for high-side MOSFET; critical for proper HS conduction.
13, 16 PGND	Power Ground	High-current return path for SW node and internal power switches; separate from AGND to avoid ground bounce.
14, 15 SW	Switch Node	Drives external inductor; carries high di/dt switching current; layout must minimize loop area to reduce EMI.
Exposed PAD	Thermal & Electrical Ground	Mandatory connection to both AGND and PGND planes for thermal dissipation (30 °C/W) and low-impedance grounding.

Key Features

Feature	Design Value
Integrated Compensation	Eliminates external Type-II/III compensation network, reducing BOM count and PCB area while guaranteeing stability across 10–100 µF output capacitance.
Two Light-Load Modes	LCM mode achieves >85% efficiency at 1 mA load; LNM enforces constant-frequency PWM for <10 mV_pp ripple in noise-sensitive instrumentation.
Programmable Spread Spectrum	±5% frequency dithering reduces peak EMI by 10 dB without altering average switching frequency or control loop behavior.
Internal Soft-Start	1.3 ms monotonic ramp prevents inrush current surges during power-up and after UVLO/thermal recovery events.
VIN-Compatible Enable	EN pin accepts up to 38 V logic signals directly-no level-shifter required when interfacing with 24 V PLC I/O or microcontroller GPIO.

Applications

Industrial 24 V Bus Power

Sensor Node Power Supply

Use Scenario: Power conversion for distributed I/O modules on 24 V factory automation buses with strict EMC and thermal constraints.

IC Role / Device Role / Timing Role: Primary buck regulator supplying 5 V to microcontrollers, CAN transceivers, and analog front-ends.

Use Value: 38 V max input withstands 24 V bus transients (IEC 61000-4-5); 30 °C/W thermal resistance enables convection-only cooling in sealed enclosures.

Use Scenario: Always-on environmental sensor node powered by LiSOCl₂ battery with 10+ year lifetime requirement.

IC Role / Device Role / Timing Role: Main power stage enabling ultra-low-quiescent operation and precise 5 V rail for ADC and RF wake-up circuitry.

Use Value: 17 μA IQ extends battery life; PGOOD enables MCU-controlled sleep/wake coordination; LCM mode maintains >80% efficiency down to 100 μA load.

Decentralized Intelligent Node

Low-Noise Instrumentation Supply

Use Scenario: Edge computing node in predictive maintenance system integrating vibration sensing, local processing, and wireless telemetry.

IC Role / Device Role / Timing Role: Central power manager delivering 5 V to ARM Cortex-M7 MCU, MEMS accelerometer, and BLE SoC.

Use Value: Synchronization capability (LNM) aligns switching edges with MCU clock domain to suppress beat frequencies in time-domain measurements.

Use Scenario: Precision analog signal chain in portable medical device requiring sub-mV ripple on 5 V supply for 24-bit sigma-delta ADC.

IC Role / Device Role / Timing Role: Low-noise post-regulator cleaning noisy upstream 12 V DC-DC output before sensitive analog stages.

Use Value: LNM mode delivers <5 mV_pp ripple at 100 mA with 40 µF MLCC; constant-frequency operation avoids spectral spreading into measurement bandwidth.

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM61480RQWR	42 V max input, 8 A output, 15 μA IQ, but requires external compensation and has no spread spectrum.	Higher current capacity suits motor drive bias rails; lacks integrated soft-start and PGOOD sequencing support.	Select when >3 A output or 42 V transient tolerance is mandatory; accept added design complexity for compensation and layout.
TPS62865ARGRR	36 V max input, 4 A output, 12 μA IQ, fixed 5 V option, but no LNM/LCM mode selection or external clock sync.	Optimized for compact portable electronics; lacks industrial-grade OVP/UVLO thresholds and 24 V bus transient robustness.	Prefer for space-constrained consumer devices where 24 V bus compatibility and noise-sensitive sync are not required.

Compared with LM61480RQWR and TPS62865ARGRR, the L6983C50QTR uniquely combines industrial 38 V input rating, dual-mode light-load optimization, external clock synchronization, and fully integrated compensation-making it the only choice for cost-sensitive, noise-critical 24 V industrial nodes requiring minimal external components.

Availability

L6983C50QTR is available at Aetrix Electronics and suitable for industrial 24 V bus power systems, battery-powered sensor nodes, decentralized intelligent edge nodes, and low-noise instrumentation requiring stable component supply across extended temperature ranges (−40 °C to +125 °C).

Supply support for L6983C50QTR 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, microcontrollers, and automotive ICs with broad industrial qualification and long-term product availability commitments.

The L6983 series targets industrial and automotive power conversion applications demanding high reliability, wide input range, and ultra-low quiescent current-designed specifically for decentralized nodes, always-on sensors, and harsh-environment 24 V systems.

FAQ

What is the difference between LCM and LNM modes in the L6983C50QTR?

LCM (Low Consumption Mode) uses pulse-skipping at light loads to achieve <20 μA quiescent current and >85% efficiency at 1 mA, ideal for battery longevity. LNM (Low Noise Mode) enforces constant-frequency PWM with minimal output ripple (<5 mV_pp), essential for precision analog and RF-sensitive applications. The mode is fixed per part number-L6983C50QTR is an LNM variant.

Can the L6983C50QTR synchronize to an external clock, and what are the requirements?

Yes-only LNM versions like L6983C50QTR support external clock synchronization via the EN/CLKIN pin. The external clock must be 200–2200 kHz square wave with amplitude ≥2.3 V and pulse width ≥60 ns (at 2.3 V) or ≥20 ns (above 2.5 V). Synchronization overrides internal oscillator and locks switching edges to the external source for EMI reduction.

How does the VBIAS pin reduce input quiescent current?

When VBIAS is connected to the regulated 5 V output, the internal bias circuitry draws operating current from VBIAS instead of VIN, reducing total input IQ from 17 μA to ~550 μA (typical for LNM). This switch-over feature cuts input power draw in always-on applications where VOUT remains active even during system sleep states.

Is the L6983C50QTR RoHS-compliant and qualified for automotive use?

The L6983C50QTR is RoHS-compliant and qualified per AEC-Q100 Grade 1 (−40 °C to +125 °C), with full industrial temperature range support. While not automotive-qualified by default, its 150 °C max junction temperature, 38 V absolute max input, and robust protection suite make it widely deployed in automotive body electronics and industrial vehicle systems meeting ISO 16750-2 transient requirements.

L6983C50QTR 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:: Fixed

Number of Outputs:: 1

Voltage - Input (Min):: 3.5V

Voltage - Input (Max):: 38V

Voltage - Output (Min/Fixed):: 5V

Voltage - Output (Max):: -

Current - Output:: 3A

Frequency - Switching:: 200kHz ~ 2.2MHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

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

L6983C50QTR FAQ

1.How can I place an order for L6983C50QTR through Aetrix?

Please submit a Request for Quotation (RFQ) for L6983C50QTR 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 L6983C50QTR reliable?

The price and inventory of L6983C50QTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L6983C50QTR is usually 5 days.

3.What payment methods are accepted for L6983C50QTR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L6983C50QTR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L6983C50QTR?

L6983C50QTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L6983C50QTR 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 L6983C50QTR?

For technical support, including L6983C50QTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L6983C50QTR requirements.

6.How does Aetrix verify that L6983C50QTR is sourced from the original manufacturer or authorized distributors?

All L6983C50QTR 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 L6983C50QTR meets industry standards.

7.What is the process for return or replacement of L6983C50QTR?

All L6983C50QTR units undergo pre-shipment inspection (PSI). If there is an issue with L6983C50QTR, 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 L6983C50QTR part is unused and in its original packaging.

Return procedure for L6983C50QTR:

1.Submit a request within 90 days.

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

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