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

STMicroelectronics L7983PU50R

Name: L7983PU50R
Brand: STMicroelectronics
SKU: L7983PU50R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L7983PU50R

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 10-WFDFN Exposed Pad

Datasheet:: L7983PU50R.pdf

Description:: IC REG BUCK 5V 300MA 10DFN

Quantity:: RFQ Add To RFQ list

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Product details

Overview

L7983PU50R from STMicroelectronics is a 60 V, 300 mA synchronous step-down DC-DC regulator with fixed 5.0 V output, peak current mode control, internal compensation, and dynamic Low Noise Mode (LNM)/Low Consumption Mode (LCM) selection. It operates from 3.5 V to 60 V input, delivers 10 µA quiescent current in LCM (VIN > 24 V), supports 200 kHz–2.2 MHz programmable switching frequency, and integrates overvoltage, thermal, and cycle-by-cycle current protection. Used in industrial 24 V/48 V bus power supplies for microcontrollers and sensors.

For engineers reviewing the L7983PU50R datasheet, L7983PU50R pinout, L7983PU50R application, or L7983PU50R equivalent, key selection criteria include its 5.0 V ±1.5% output accuracy at 25 °C, 2.3 µA shutdown current, RST open-collector reset output with 92% VREF release threshold, and LNM/LCM pin-controlled noise-efficiency trade-off - critical for fail-safe sensor nodes and battery-powered edge devices.

Technical Context

The L7983PU50R implements a peak current mode, constant-frequency buck architecture with integrated high-side P-MOSFET and low-side N-MOSFET, anti-shoot-through logic, and adaptive dead-time control. Its internal trans-conductor (gm) error amplifier and slope-compensated PWM comparator enable stable regulation without external compensation components.

Dynamic mode selection via the LNM/LCM pin enables real-time switching between constant-frequency LNM (for low ripple and fast transient response) and variable-frequency LCM (for <10 µA light-load IQ). Synchronization to external clocks (180–2400 kHz) and spread-spectrum dithering further reduce EMI in noise-sensitive applications.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	3.5 V to 60 V - supports direct connection to 12 V, 24 V, and 48 V industrial buses without pre-regulation.
Output Voltage	Fixed 5.000 V ±0.5% (typ.) at 25 °C - internally trimmed reference eliminates external resistor divider for fixed-output use.
Output Current	300 mA DC continuous - sufficient for powering microcontrollers, FPGAs, and analog sensors in decentralized nodes.
Quiescent Current	10 µA in LCM (VIN > 24 V) - enables multi-year battery life in always-on IoT endpoints.
Switching Frequency	200 kHz to 2.2 MHz programmable via FSW pin resistor - allows optimization of size (high fSW) vs. efficiency (low fSW).
Reset Output (RST)	Open-drain, active-low, 92% VREF release threshold with 2 ms delay - provides reliable power-up sequencing for digital loads.
OVP Threshold	120% of VREF (i.e., 6.0 V for L7983PU50R) with 2% hysteresis - prevents damage to downstream 5 V logic during overvoltage faults.
Thermal Shutdown	165 °C trip with 30 °C hysteresis - protects against sustained overload or poor PCB thermal design.

Pinout & Package

Package: HTSSOP-10 (exposed pad), 3.1 mm × 3.1 mm × 1.0 mm, RoHS-compliant, thermal resistance R_thJA = 50 °C/W on standard demo board.

Pin/Terminal	Circuit Role	Design Meaning
1 VOUT/FB	Output voltage sensing / feedback node	Internally connected to 5.0 V divider; shorted to output capacitor for fixed-output operation - no external resistors required.
2 VBIAS	Bias supply input for internal LDO	Connect to VOUT or auxiliary rail to improve light-load efficiency; tie to GND if unused - enables switchover to lower-loss bias path.
3 VCC	Internal LDO output	Supplies analog circuitry; requires 470 nF ceramic bypass to GND - not intended for external loading.
4 FSW	Switching frequency programming	Resistor-to-GND or VCC sets f_SW from 200 kHz to 2.2 MHz - pinstrapping occurs before soft-start to minimize startup current.
5 LNM/LCM	Mode selection / clock sync input	High = LNM (constant f_SW, low ripple); low = LCM (variable f_SW, ultra-low IQ); also accepts 180–2400 kHz external clock.
6 RST	Open-drain reset output	Asserts low when VOUT drops below 92% of VREF or OVP occurs; releases after 2 ms delay and hysteresis recovery - enables MCU/FPGA power sequencing.
7 EN/UVLO	Enable / input undervoltage lockout	VIN-compatible; external resistor divider programs UVLO threshold - ensures clean start-up only above valid bus voltage.
8 VIN	Main power input	Accepts 3.5–60 V DC; feeds both power stage and internal LDO - designed for harsh industrial environments with wide input transients.
9 LX	Switching node	Connects HS and LS MOSFET drains; requires low-ESR ceramic output capacitor and shielded inductor - critical for EMI and efficiency.
10 GND + EP	Power and signal ground / thermal pad	Exposed pad must be soldered to PCB ground plane - primary thermal path; reduces junction temperature rise by ~30 °C under full load.

Key Features

Feature	Design Value
Integrated synchronous power stage	P-channel HS + N-channel LS MOSFETs with anti-shoot-through and adaptive dead-time - eliminates external diode, achieves >90% efficiency at medium load.
Dynamic LNM/LCM mode switching	Real-time pin-controlled transition between low-noise (constant f_SW) and low-IQ (skip-mode) operation - adapts to changing system load without firmware intervention.
Programmable spread-spectrum dithering	±5% triangular frequency modulation via FSW pin configuration - reduces peak EMI by up to 10 dB without increasing output ripple significantly.
Internal soft-start and reset supervision	Fixed 2 ms soft-start time + RST open-collector output with 92% VREF threshold - ensures glitch-free power-up of digital loads and avoids brown-out resets.
Robust fault protection suite	Cycle-by-cycle OCP, valley-current limit, overvoltage (120% VREF), thermal shutdown (165 °C), and UVLO - all auto-recovering with no latch-up behavior.
VIN-compatible enable with UVLO programming	EN pin accepts up to 60 V; external resistor divider sets precise turn-on voltage - simplifies interface with unregulated industrial buses.

Applications

Industrial 24 V Bus Power

Failsafe Sensor Node

Use Scenario: Powering PLC I/O modules and fieldbus gateways on 24 V DC industrial networks with wide input variation and EMI constraints.

IC Role / Device Role / Timing Role: Primary point-of-load regulator delivering stable 5 V to microcontrollers and isolated communication ICs.

Use Value: 60 V max input withstands 48 V transients; LNM mode ensures low ripple for analog sensor front-ends; RST enables coordinated system reset.

Use Scenario: Battery-backed environmental monitoring node operating continuously for years in remote locations.

IC Role / Device Role / Timing Role: Main system regulator managing sleep/wake cycles with ultra-low quiescent current during idle periods.

Use Value: 10 µA LCM IQ extends battery life; dynamic LNM activation during data acquisition ensures clean 5 V for ADC references and RF transmission.

Decentralized Edge Controller

Fail-Safe Safety PLC Module

Use Scenario: Compact motor control node with local processing, CAN interface, and analog feedback conditioning.

IC Role / Device Role / Timing Role: Single-chip 5 V supply supporting MCU, gate drivers, and isolated analog front-end.

Use Value: Internal compensation eliminates loop tuning effort; spread-spectrum dithering meets Class B EMC requirements without added shielding.

Use Scenario: SIL-2 compliant safety module requiring deterministic power-up sequencing and fault detection.

IC Role / Device Role / Timing Role: Regulator with RST output synchronized to system watchdog and monitored VOUT supervisor.

Use Value: 2 ms RST delay and 2% hysteresis ensure robust reset assertion during brown-out; OVP and OTP provide redundant fault coverage.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
LMR36506RNXR	65 V input, 600 mA output, 26 µA IQ in FPWM mode, no LNM/LCM dynamic switching	Lacks real-time noise-efficiency mode toggle; fixed PWM only - less optimal for mixed-signal systems with bursty loads	Choose for higher current needs where constant-frequency operation suffices and external compensation is acceptable.
TPS63020DSJR	Buck-boost topology, 1.8–5.5 V output, 3 A switch current, 25 µA IQ - no 60 V rating	Supports output voltages below input (e.g., 3.3 V from 5 V), but cannot regulate from 48 V bus directly	Choose only for battery-powered systems with narrow VIN range and bidirectional voltage conversion requirements.

Compared with LMR36506RNXR and TPS63020DSJR, the L7983PU50R uniquely combines 60 V industrial bus compatibility, true dynamic LNM/LCM selection, and integrated reset sequencing - making it the only option that simultaneously satisfies high-voltage resilience, ultra-low standby power, and fail-safe digital load management in a single 10-pin package.

Availability

L7983PU50R is available at Aetrix Electronics and suitable for industrial automation, battery-powered edge sensors, and failsafe safety PLC modules requiring stable component supply across extended product lifecycles.

Supply support for L7983PU50R 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-grade ICs with vertical manufacturing and long-term product longevity commitments.

The L7983 series belongs to ST's high-voltage industrial DC-DC regulator portfolio, engineered specifically for robust, low-maintenance power conversion in 12 V/24 V/48 V bus systems where reliability, EMI control, and intelligent mode adaptation are mandatory.

FAQ

What is the recommended input capacitor for L7983PU50R in a 48 V bus application?

A minimum 4.7 µF X7R ceramic capacitor rated for ≥63 V must be placed within 3 mm of the VIN and GND pins. For 48 V bus transients, ST recommends paralleling with a 10 µF tantalum or polymer capacitor to handle high RMS ripple current and suppress low-frequency surges per DS13354 Section 7.2.

Can L7983PU50R operate with VBIAS grounded while delivering full 300 mA output?

Yes - grounding VBIAS disables the switchover function and powers the internal LDO from VIN, which is fully supported per datasheet Table 5. However, quiescent current increases to 35–50 µA (vs. 3–6 µA with VBIAS = 5 V), and efficiency drops ~3% at light load due to higher LDO dropout losses.

How does the RST pin behave during output pre-bias conditions?

The L7983PU50R actively prevents reverse current flow during soft-start: if VOUT is pre-biased above VRSTTHR before startup, RST remains floating (high-Z) until the internal reference stabilizes and regulation begins. No sinking occurs - ensuring safe hot-plug and back-powering scenarios per Section 5.4.

Is spread-spectrum dithering enabled by default on L7983PU50R?

No - dithering is disabled by default. It is activated only when the FSW pin resistor is connected to VCC (not GND), per Table 7 in DS13354. The dithering frequency is FDITH = fSW / 126, producing ±5% triangular modulation - confirmed by oscilloscope measurement of LX waveform in Application Note AN5074.

L7983PU50R Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 10-WFDFN 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):: 60V

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

Voltage - Output (Max):: -

Current - Output:: 300mA

Frequency - Switching:: 200kHz ~ 2.2MHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

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

L7983PU50R FAQ

1.How can I place an order for L7983PU50R through Aetrix?

Please submit a Request for Quotation (RFQ) for L7983PU50R 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 L7983PU50R reliable?

The price and inventory of L7983PU50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L7983PU50R is usually 5 days.

3.What payment methods are accepted for L7983PU50R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L7983PU50R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L7983PU50R?

L7983PU50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L7983PU50R 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 L7983PU50R?

For technical support, including L7983PU50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L7983PU50R requirements.

6.How does Aetrix verify that L7983PU50R is sourced from the original manufacturer or authorized distributors?

All L7983PU50R 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 L7983PU50R meets industry standards.

7.What is the process for return or replacement of L7983PU50R?

All L7983PU50R units undergo pre-shipment inspection (PSI). If there is an issue with L7983PU50R, 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 L7983PU50R part is unused and in its original packaging.

Return procedure for L7983PU50R:

1.Submit a request within 90 days.

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

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