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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > PFC (Power Factor Correction)

STMicroelectronics E-L4981AD

Name: E-L4981AD
Brand: STMicroelectronics
SKU: E-L4981AD
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: E-L4981AD

Manufacturer:: STMicroelectronics

Category:: PFC (Power Factor Correction)

Package:: 20-SOIC (0.295", 7.50mm Width)

Datasheet:: E-L4981AD.pdf

Description:: IC PFC CTR AVER CURR 100KHZ 20SO

Quantity:: RFQ Add To RFQ list

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Product details

Overview

E-L4981AD from STMicroelectronics is a fixed-frequency average-current-mode Power Factor Correction (PFC) controller IC in SO-20 package, designed for boost pre-regulator stages in AC/DC power supplies. It delivers up to 0.99 power factor, limits line current THD to <5%, supports universal 85–265V_AC input, and integrates bipolar/DMOS totem-pole gate driver with 1A peak sink/source capability.

For engineers reviewing the E-L4981AD datasheet, E-L4981AD pinout, E-L4981AD application, or E-L4981AD equivalent, key selection criteria include its fixed-frequency operation (L4981A variant), programmable UVLO threshold, integrated 5.1V ±2% reference, soft-start timing via external capacitor, and dual protection (OVP/OCP) with external resistor programming.

Technical Context

The E-L4981AD implements average-current-mode PWM control without slope compensation, using a multiplier that combines VRMS, VA-OUT, and LFF inputs to generate precise sinusoidal current reference. Its internal oscillator sets switching frequency via ROSC/COSC (typ. 100 kHz), and it features feed-forward line regulation via VRMS and load regulation via LFF to minimize transient response delay.

Protection architecture includes overvoltage detection at Pin 3 referenced to internal 5.1V comparator with 250mV hysteresis, and overcurrent sensing at Pin 2 with programmable threshold (via resistor network). The device operates with 0.3mA typical start-up current and includes internal MOS discharge for SS capacitor during UVLO or OVP events.

Key Specifications

Parameter	Value and Actual Design Meaning
Power Factor	Up to 0.99 - enables compliance with IEC 61000-3-2 Class D harmonic limits.
THD Limit	<5% line current distortion - ensures low harmonic injection into mains.
Input Voltage Range	85–265V_AC universal - eliminates manual line-voltage switch in global power supplies.
Reference Voltage	5.1V ±2% - provides stable feedback reference for voltage loop and external circuitry.
Gate Driver Output	1A sink / 1.5A source peak - directly drives MOSFET/IGBT gates without external buffer.
Start-up Current	0.3mA typ. - reduces auxiliary supply burden during initial power-up.
UVLO Threshold	Programmable 10.6–13.4V turn-on - allows adaptive brown-out recovery based on bulk capacitor voltage.
Oscillator Frequency	100kHz typ. (±15%) - sets boost converter switching speed for optimized magnetics and EMI filtering.

Pinout & Package

Package: SO-20 (SOIC-20), 7.4mm × 12.6mm body, 1.27mm pitch, JEDEC MS-013 compliant.

Pin/Terminal	Circuit Role	Design Meaning
1	P-GND	Power ground return for gate driver and high-current paths - must be low-inductance connection to PCB ground plane.
2	IPK	Peak current limit sense input - sets OCP threshold via resistor divider to VREF (Pin 11); precision configuration required for L4981A.
3	OVP	Overvoltage protection comparator input - monitors boosted output via resistive divider; trips if exceeds 5.1V reference + hysteresis.
4	IAC	AC current proportional input - receives rectified line current signal to generate instantaneous current reference for multiplier.
5	CA-OUT	Current amplifier output - drives external RC compensation network to stabilize inner current loop bandwidth and phase margin.
11	VREF	5.1V ±2% reference output - powers external dividers, bias networks, and serves as precision reference for IPK and UVLO circuits.
12	SS	Soft-start timing node - 100µA internal current charges external capacitor; discharge path active during fault conditions.
13	VA-OUT	Error amplifier output - controls outer voltage loop; requires external RC network to set gain and pole-zero placement.
14	VFEED	Voltage feedback inverting input - connects to output voltage divider; sets regulated DC bus voltage (e.g., 400V).
15	P-UVLO	Programmable UVLO threshold input - resistor divider from VCC to GND sets turn-on voltage (e.g., 12V with 220kΩ/33kΩ).
16	SYNC	Synchronization input/output - accepts CMOS-level clock for master-slave PFC coordination or outputs sync pulse for downstream controllers.
17	ROSC	Oscillator charging current setting - external resistor defines constant current into COSC (Pin 18) to set f_SW.
18	COSC	Oscillator timing capacitor - sets switching frequency with ROSC; 1nF + 24kΩ yields ~100kHz.
19	VCC	Supply input - operates from 12–19.5V; includes internal zener clamp (25V max) and UVLO circuitry.
20	GDRV	Gate driver output - totem-pole bipolar/DMOS stage drives high-side boost switch; capable of 1A sink at 0.8V saturation.

Key Features

Feature	Design Value
Average-current-mode PWM	Eliminates need for slope compensation, enabling stable operation across wide line/load ranges with minimal noise sensitivity.
Integrated 5.1V ±2% reference	Externally accessible reference reduces BOM count and improves voltage-loop accuracy versus discrete references.
Programmable UVLO with hysteresis	Configurable turn-on/off thresholds (e.g., 12V ON / 10.5V OFF) prevent oscillatory startup during brownouts.
Dual-protection architecture	OVP (Pin 3) and OCP (Pin 2) with independent thresholds enable robust fault handling without external comparators.
Feed-forward line and load regulation	VRMS (Pin 7) and LFF (Pin 6) inputs dynamically adjust current reference to maintain PF and reduce output ripple under transients.
Low-startup current (0.3mA)	Minimizes auxiliary supply design complexity and losses in offline adapters with capacitive dropper or HV startup circuits.

Applications

Industrial Motor Drives

Medical Imaging Power Supplies

Use Scenario: 3-phase AC input rectified to DC bus feeding IGBT inverter stages in servo drives.

IC Role / Device Role / Timing Role: PFC pre-regulator controlling boost stage to maintain 0.99 PF and limit THD below 5% per IEC 61000-3-2.

Use Value: Enables compliance with strict industrial harmonic standards while delivering stable 400V DC bus for inverter stage efficiency.

Use Scenario: High-reliability CT scanner power system requiring clean, regulated DC for X-ray generator and detector electronics.

IC Role / Device Role / Timing Role: Fixed-frequency PFC controller managing boost converter to sustain 400V output with <2.2% THD at 110V_AC nominal input.

Use Value: Guarantees low-noise, low-distortion input current critical for sensitive analog front-end stability and image fidelity.

Telecom Rectifier Modules

LED Streetlight Drivers

Use Scenario: -48V telecom system with AC front-end supporting hot-swap and N+1 redundancy.

IC Role / Device Role / Timing Role: Primary PFC controller in 360W rectifier module operating from 88–264V_AC, regulating 400V bus with 94.5% efficiency at 132V_AC.

Use Value: Delivers high efficiency and thermal margin across universal input range while meeting GR-1089-CORE EMI requirements.

Use Scenario: Outdoor LED streetlight with universal AC input and isolated DC-DC stage driving constant-current LED strings.

IC Role / Device Role / Timing Role: Boost PFC controller ensuring >0.98 PF and <6.4% THD at 220V_AC, enabling single-stage topology with reduced component count.

Use Value: Meets EN 61000-3-2 Class C limits for lighting equipment while simplifying thermal design via high-efficiency operation.

Equivalent & Alternatives

The following parts are listed as comparable options for similar power factor correction controller applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
UCC28070	Interleaved dual-channel CCM PFC controller; no integrated gate driver; requires external high-side driver.	Targeted at higher-power (>500W) interleaved designs; lacks single-chip boost gate drive.	Select when scaling beyond 400W or requiring channel interleaving for lower ripple and EMI.
FAN4803	Fixed-frequency average-current-mode PFC; 5.0V reference (±1.5%); lower gate drive (0.5A peak); no LFF/VRMS feed-forward.	Optimized for cost-sensitive <200W applications; reduced transient response vs. L4981AD.	Select for compact, lower-cost designs where full feed-forward capability is not required.

Compared with UCC28070 and FAN4803, E-L4981AD uniquely integrates a 1A gate driver, programmable UVLO, and dual feed-forward (VRMS/LFF) for superior line/load transient response in universal-input 200–400W boost PFC stages.

Availability

E-L4981AD is available at Aetrix Electronics and suitable for industrial motor drives, medical imaging power supplies, telecom rectifier modules, and LED streetlight drivers requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for E-L4981AD 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, specializing in power management, analog, microcontrollers, and automotive ICs.

E-L4981AD belongs to ST's legacy MultiPower BCD technology PFC controller family, engineered for high-efficiency, universal-input AC/DC front-ends in industrial and medical power systems.

FAQ

What is the maximum recommended switching frequency for E-L4981AD?

The E-L4981AD is characterized for 85–115 kHz operation (typ. 100 kHz) with ROSC = 24 kΩ and COSC = 1 nF. Exceeding 120 kHz risks instability due to propagation delays in internal comparators and reduced gate driver slew rate margin; ST recommends staying within datasheet-specified 80–100 kHz range for production designs.

Can E-L4981AD operate without the VRMS and LFF pins connected?

Yes - VRMS (Pin 7) and LFF (Pin 6) may be tied to VREF (Pin 11) if feed-forward compensation is not required. However, doing so degrades line and load transient response: THD increases by ~1.5–2.5% under step-load changes, and output voltage overshoot rises by 8–12V during 50% load steps, per ST AN628 evaluation data.

How is overcurrent protection configured for E-L4981AD?

OCP is set via a resistor network between IPK (Pin 2), VREF (Pin 11), and the current-sense resistor. For example, a 10kΩ resistor from Pin 2 to VREF and 2.2kΩ from Pin 2 to sense resistor yields ~6.2A peak current limit at 100mV sense voltage, matching the 200W demo board configuration shown in Figure 9A.

Does E-L4981AD support synchronization with other controllers?

Yes - Pin 16 (SYNC) functions as both input and output. As input, it accepts CMOS-level rectangular wave (≥100ns pulse width) to lock E-L4981AD's oscillator; as output, it delivers synchronized clock pulses (0.3–0.8 µs width) to coordinate multiple PFC stages or downstream PWM controllers, reducing beat-frequency EMI.

E-L4981AD Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 20-SOIC (0.295", 7.50mm Width)

Packaging:: Tube

Product Status:: Obsolete

Mode:: Average Current

Frequency - Switching:: 100kHz

Current - Startup:: 100 µA

Voltage - Supply:: 14.5V ~ 19.5V

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-SO

E-L4981AD FAQ

1.How can I place an order for E-L4981AD through Aetrix?

Please submit a Request for Quotation (RFQ) for E-L4981AD 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 E-L4981AD reliable?

The price and inventory of E-L4981AD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for E-L4981AD is usually 5 days.

3.What payment methods are accepted for E-L4981AD?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for E-L4981AD transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for E-L4981AD?

E-L4981AD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your E-L4981AD 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 E-L4981AD?

For technical support, including E-L4981AD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your E-L4981AD requirements.

6.How does Aetrix verify that E-L4981AD is sourced from the original manufacturer or authorized distributors?

All E-L4981AD 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 E-L4981AD meets industry standards.

7.What is the process for return or replacement of E-L4981AD?

All E-L4981AD units undergo pre-shipment inspection (PSI). If there is an issue with E-L4981AD, 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 E-L4981AD part is unused and in its original packaging.

Return procedure for E-L4981AD:

1.Submit a request within 90 days.

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

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