PMIC - AC DC Converters, Offline Switchers

Part Number	Description / PDF	Quantity
NCP1001P	SWITCHING REGLTR, VOLTAGE-MODE	1300
UC2875DWP Texas Instruments	IC REG CTRLR PWM CM/VM 28-SOIC	6049400
LNK6766K Power Integrations	IC OFFLINE SW 300MA 650V 12ESOP	0
LNK3294G-TL Power Integrations	120 MA (MDCM) 170 MA (CCM)	1849
BM2P031 ROHM Semiconductor	IC CONV DC/DC PWM 0.775MA 7DIP	2000
UC3823DWTR Texas Instruments	IC REG CTRLR PWM CM/VM 16-SOIC	1790
NCP1077STAT3G Sanyo Semiconductor/ON Semiconductor	IC REG SWITCHING HV SMPS SOT223	21
FSQ0465RBWDTU	SWITCHING REGULATOR	21632
TOP271VG Power Integrations	IC OFFLINE SW PWM OCP OVP 12EDIP	152
TOP247R-TL Power Integrations	IC OFFLINE SWIT UVLO HV D2PAK	173
TEA1738FT/N1,118 NXP Semiconductors	IC CTRLR SMPS GREEN OVP 8SO	44998
NCP1200P60	SWITCHING CONTROLLER	65301
UCC2888D Texas Instruments	SWITCHING CONTROLLER	17010
LNK4002S-TL Power Integrations	IC OFF-LINE CNTRLR 6.5W SOT23-6	0
FAN302ULMY	BATTERY CHARGE CONTROLLER, CURRE	22395
ICE5QR2280AZXKLA1 IR (Infineon Technologies)	IC CTLR QUASI-RES 7DIP	0
NCP1336ADR2G	QUASI-RES CUR MODE CONTRL	19500
FSFR1800 Sanyo Semiconductor/ON Semiconductor	IC SWIT PROG OVP OCP 9SIP	441
LNK6666E Power Integrations	IC OFF-LINE SWITCH PWM 7SIP	320
LNK614PG Power Integrations	IC OFFLINE SWIT OTP CV/CC 8DIP	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