PMIC - AC DC Converters, Offline Switchers

Image	Part Number	Description / PDF	Quantity	Rfq
	LX1554IDM Microsemi	IC REG CTRLR PWM CM 8SOIC	0
	LX1552ID Microsemi	IC REG CTRLR PWM CM 14-SOIC	0
	LX1552CDM Microsemi	IC REG CTRLR PWM CM 8SOIC	0
	LX1554IM Microsemi	IC REG CTRLR PWM CM 8-DIP	0
	LX1554CD Microsemi	IC REG CTRLR PWM CM 14-SOIC	0
	LX1552IDM Microsemi	IC REG CTRLR PWM CM 8SOIC	0
	LX1554CPW Microsemi	IC REG CTRLR PWM CM 20-TSSOP	0
	LX1552MY Microsemi	IC REG CTRLR PWM CM 8-DIP	0
	LX1552CPW Microsemi	IC REG CTRLR PWM CM 20-TSSOP	0
	LX1552IM Microsemi	IC REG CTRLR PWM CM 8-DIP	0
	LX1554ID Microsemi	IC REG CTRLR PWM CM 14-SOIC	0
	SG3842M Microsemi	IC REG CTRLR FLYBK ISO PWM 8-DIP	0
	IPS18I-D-G-LF Microsemi	POE PSE CONTROLLER	0
	SG2842DM Microsemi	IC REG CTRLR FLYBK ISO PWM 8SOIC	0
	LX1552CM Microsemi	IC REG CTRLR PWM CM 8-DIP	0
	SG3844DM Microsemi	IC REG CTRLR ISO CM 8-SOIC	0
	LX1554CDM Microsemi	IC REG CTRLR PWM CM 8SOIC	0
	IPS15C-SO-G-LF-TR Microsemi	POE PSE CONTROLLER	0
	LX1554MY Microsemi	IC REG CTRLR PWM CM 8-DIP	0
	SG2844DM Microsemi	IC PWM CURRENT MODE 8SOIC	0

PMIC - AC DC Converters, Offline Switchers

1. Overview

AC-DC converters and offline switchers are critical subcategories of Power Management Integrated Circuits (PMICs) that convert alternating current (AC) from mains power to direct current (DC) for electronic devices. Offline switchers directly regulate input voltage without requiring a line-frequency transformer, enabling compact and efficient designs. These components are essential in modern electronics for ensuring stable power delivery, energy efficiency, and compliance with global standards like Energy Star and CoC Tier-2.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Flyback Controllers	Isolated topology with energy storage in transformer; suitable for low-to-medium power	Mobile chargers, adapter supplies
Forward Controllers	Higher efficiency for medium-to-high power; requires reset circuitry	Industrial power supplies, telecom rectifiers
Resonant Controllers	ZVS/ZCS techniques for minimal switching losses; high-frequency operation	High-end server PSUs, wireless charging
PFC-Precursors	Boosts power factor to meet regulatory limits; often paired with main converters	Appliances, LED drivers

3. Structure and Components

Typical physical structure includes:

Package Types: DIP, SOP, QFN, or custom power packages
Internal Components:
- Power MOSFET/BJT switches
- PWM/PFM controllers
- Voltage/current feedback circuits
- Protection modules (OVP, OCP, OTP)
- High-voltage startup circuits

Technical composition integrates primary-side regulation (PSR) or secondary-side feedback with optocouplers, often supporting synchronous rectification for efficiency optimization.

4. Key Technical Parameters

Parameter	Description	Importance
Input Voltage Range	85-265V AC or 120-400V DC	Global compatibility and surge tolerance
Output Power	1W-500W depending on topology	Determines application scope
Switching Frequency	20kHz-2MHz	Affects EMI, transformer size, and efficiency
Efficiency	85%-96% (varies with load)	Thermal performance and energy costs
Protection Features	Overvoltage, overcurrent, thermal shutdown	System reliability and safety compliance

5. Application Fields

Consumer Electronics: Phone chargers, notebook adapters, smart home devices
Industrial: Automation equipment, PLCs, test instruments
Medical: Isolated power supplies for diagnostic equipment
Telecom: 48V rectifiers, base station power systems
Automotive: On-board chargers, vehicle AC-DC systems

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
Texas Instruments	UCC28780	High-frequency resonant controller with GaN support
STMicroelectronics	L6565	Current-mode flyback controller for adapters
Infineon	ICE3BR1765	Integrated CoolSET for SMPS
ON Semiconductor	NCP1342	Quasi-resonant flyback controller
Monolithic Power Systems	MP44010	Primary-side regulated controller

7. Selection Guidelines

Define input/output requirements (voltage, current, power)
Choose topology based on isolation needs and efficiency targets
Evaluate protection features for mission-critical applications
Consider package thermal performance (e.g., exposed pads)
Verify compliance with standards (UL, CE, FCC)
Balance cost vs. integration level (e.g., controller vs. digital PMIC)

Case Study: For a 65W USB-C laptop adapter, select a high-frequency resonant controller with synchronous rectification to achieve >92% efficiency and compact form factor.

8. Industry Trends

Integration: Combining PFC + LLC stages into single chips
Wide Bandgap: SiC/GaN FETs enabling >1MHz switching
Digital Control: Programmable PMICs with real-time optimization
Green Standards: Meeting EU CoC Tier-2 no-load <10mW requirements
AEC-Q Compliance: Growth in automotive-grade offline converters