PMIC - Voltage Regulators - Linear + Switching

Part Number	Description / PDF	Quantity
L5963DN-EHX STMicroelectronics	IC REG TRP BCK/LNR SYNC PWRSSO36	0
L5963U-KBX STMicroelectronics	IC REG TRP BCK/LNR SYNC PWRSSO36	0
L5963DN-EHT STMicroelectronics	IC REG TRP BCK/LNR SYNC PWRSSO36	0
L5963U-KBT STMicroelectronics	IC REG TRP BCK/LNR SYNC PWRSSO36	0
L5964L-VYY STMicroelectronics	IC REG TRPL BUCK/LNR SYNC 64LQFP	0
L5963Q-V0Y STMicroelectronics	IC REG TRP BCK/LNR SYNC 48VFQFPN	3
L9305EP STMicroelectronics	PTS ASSP	0
L9305EP-TR STMicroelectronics	PTS ASSP	0
L9369-TR STMicroelectronics	ELECTRONIC DUAL H-BRIDGE PRE-DRI	0
L5963Q-V0T STMicroelectronics	IC REG TRP BCK/LNR SYNC 48VFQFPN	0
L9749TR STMicroelectronics	POWER TRAIN & SAFETY	0
L9749 STMicroelectronics	POWER TRAIN & SAFETY	0
L9369 STMicroelectronics	PTS ASSP	0
L5963D-EHX STMicroelectronics	IC REG TRPL BUCK/LNR SYNC 36PSSO	0
PM6675S STMicroelectronics	IC REG DL BCK/LNR 33KHZ 24VFQFPN	0
PM6681ATR STMicroelectronics	IC REG QUAD BUCK/LINEAR 32VFQFPN	0
PM6675TR STMicroelectronics	IC REG DL BCK/LNR 33KHZ 24VFQFPN	0
PM6675AS STMicroelectronics	IC REG DL BCK/LNR 33KHZ 24VFQFPN	0
PM6681A STMicroelectronics	IC REG QUAD BUCK/LINEAR 32VFQFPN	0
L5963D-EHT STMicroelectronics	IC REG TRP BCK/LNR SYNC PWRSSO36	0

PMIC - Voltage Regulators - Linear + Switching

1. Overview

Power Management ICs (PMICs) voltage regulators are semiconductor devices that maintain stable output voltages despite input variations. They are critical in modern electronics for ensuring reliable operation of sensitive components. Linear regulators use resistive control for low-noise outputs, while switching regulators employ high-frequency switching for higher efficiency. These devices enable optimal power distribution in applications ranging from mobile devices to industrial systems.

2. Main Types & Functional Classification

Type	Functional Characteristics	Application Examples
Linear Regulators (LDO)	Low noise, simple design, lower efficiency (typically 40-60%), dropout voltage ~0.1V	RF circuits, audio amplifiers, battery-powered devices
Buck Converters	Step-down topology, 80-95% efficiency, requires inductor	CPU/GPU power supplies, DC-DC modules
Boost Converters	Step-up topology, synchronous design for <90% efficiency	LED drivers, battery backup systems
Buck-Boost Converters	Inverting topology, handles input voltage variations	Portable electronics, automotive systems

3. Structure & Composition

Typical voltage regulator ICs consist of: 1) Reference voltage circuit (bandgap), 2) Error amplifier, 3) Pass transistor (MOSFET/BJT), 4) Feedback network, 5) Protection circuits (OCP/OTP). Switching regulators integrate PWM controllers and gate drivers, while linear types use simpler architectures. Common packages include QFN (3x3mm to 5x5mm), TSSOP, and BGA with thermal pads.

4. Key Technical Parameters

Parameter	Description & Importance
Input Voltage Range	Operating limits (e.g., 2.5V-5.5V for LDOs, 4.5V-60V for DC-DC)
Output Voltage Accuracy	Tolerance level ( 1% to 5% for precision applications)
Efficiency	Power conversion ratio (critical for thermal design)
Ripple Rejection	PSRR value (e.g., 60dB@1kHz for noise-sensitive circuits)
Transient Response	Stability under load changes (e.g., 50mV deviation for 1A/ s steps)
Quiescent Current	Standby consumption (critical for battery life)

5. Application Fields

Consumer: Smartphones, wearables, gaming consoles
Automotive: ADAS systems, infotainment, ECU units
Industrial: PLCs, motor drives, test equipment
Telecom: Base stations, optical transceivers, routers
Medical: Imaging systems, patient monitors, diagnostic devices

6. Leading Manufacturers & Products

Manufacturer	Representative Product	Key Features
Texas Instruments	LM2678	3A step-down converter, 65V input
STMicroelectronics	L7981	Synchronous buck regulator, 2A output
ON Semiconductor	NCP1117	Low-dropout linear regulator, 1A current
Analog Devices	LT8640S	High-efficiency buck converter, 42V input

7. Selection Guidelines

Key considerations: 1) Input/output voltage requirements, 2) Load current profile (steady vs. transient), 3) Efficiency vs. noise trade-offs, 4) Thermal management (package thermal resistance), 5) External component requirements (inductors, capacitors), 6) Operating temperature range (-40 C to +125 C automotive grade), 7) Cost vs. integration level.

8. Industry Trends

Current developments include: - Higher integration (PMICs combining multiple rails) - Wide bandgap semiconductors (GaN/SiC for high-frequency switching) - Digital control implementation (PMBus interface adoption) - Advanced packaging (3D stacking for low inductance) - Energy harvesting compatibility (sub-1V input capability) - AEC-Q100 automotive qualification becoming standard