PMIC - Voltage Regulators

PMIC - Voltage Regulators - Linear

Part Number	Description / PDF	Quantity
FT531AA Fremont Micro Devices	IC REG LINEAR 1.2V 250MA SOT23-5	13799
FT511AB Fremont Micro Devices	IC REG LIN 1.2V 150MA SOT89-3LA	0
FT533IA Fremont Micro Devices	IC REG LINEAR 3V 400MA SOT23-5	0
FT531GA Fremont Micro Devices	IC REG LINEAR 2.8V 250MA SOT23-5	0
FT533GA Fremont Micro Devices	IC REG LINEAR 2.8V 400MA SOT23-5	0
FT511BB Fremont Micro Devices	IC REG LIN 1.5V 150MA SOT89-3LA	0
FT531JA Fremont Micro Devices	IC REG LINEAR 3.3V 250MA SOT23-5	0
FT531CA Fremont Micro Devices	IC REG LINEAR 1.5V 250MA SOT23-5	0
FT510EB Fremont Micro Devices	IC REG LIN 2.8V 250MA SOT89-3LA	0
FT533DA Fremont Micro Devices	IC REG LINEAR 1.8V 400MA SOT23-5	0
FT511DB Fremont Micro Devices	IC REG LIN 2.5V 150MA SOT89-3LA	0
FT531IA Fremont Micro Devices	IC REG LINEAR 3V 250MA SOT23-5	0
FT510FB Fremont Micro Devices	IC REG LINEAR 3V 250MA SOT89-3LA	0
FT510GB Fremont Micro Devices	IC REG LIN 3.3V 250MA SOT89-3LA	0
FT531EA Fremont Micro Devices	IC REG LINEAR 2.5V 250MA SOT23-5	0

PMIC - Voltage Regulators - Linear

1. Overview

Linear Voltage Regulators (LVRs) are critical components in Power Management Integrated Circuits (PMICs) that provide stable output voltage levels by dissipating excess input energy as heat. Unlike switching regulators, LVRs operate without high-frequency switching, making them ideal for noise-sensitive applications. Their importance in modern electronics includes ensuring power integrity in portable devices, industrial equipment, and automotive systems.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Low Dropout (LDO) Regulators	Maintain regulation with minimal input-output voltage differential (e.g., 100mV)	Mobile device sensors, RF circuits
Quasi-LDO Regulators	Balance dropout voltage and load current capability	Intermediate power stages in IoT devices
Dual/Multi-Output LVRs	Single-chip solutions with multiple regulated outputs	Application processors in smartwatches
High-Precision LVRs	0.5% output voltage accuracy with temperature compensation	Medical imaging sensors, test equipment

3. Structure and Components

Typical LVR architecture includes:

Reference Voltage Source (bandgap circuit)
Error Amplifier with feedback loop
Pass Transistor (NMOS/PMOS/BJT) as active regulation element
Thermal Shutdown and Overcurrent Protection Circuits
Input/Output Capacitor Interfaces

Common packages: QFN (3x3mm), TSSOP, WLCSP for portable devices. High-power variants use flip-chip with exposed thermal pads.

4. Key Technical Specifications

Parameter	Description	Importance
Input Voltage Range	Operational voltage limits (e.g., 2.7V-5.5V)	Determines compatibility with power sources
Output Voltage Accuracy	Deviation from nominal value ( 1% to 3%)	System stability and component protection
Dropout Voltage	Minimum Vin-Vout for regulation (e.g., 30mV-300mV)	Battery life optimization in portable devices
Output Current Capability	Max continuous load current (100mA-3A)	Application scalability
PSRR (Power Supply Rejection Ratio)	Noise attenuation at specific frequencies (e.g., 70dB at 1kHz)	Signal integrity in analog circuits
Quiescent Current	Standby power consumption (1 A-100 A)	Battery efficiency in always-on systems

5. Application Areas

Consumer Electronics: Smartphone APUs, SSD controllers
Industrial Automation: PLC signal conditioning modules
Automotive: ADAS sensors, infotainment system peripherals
Medical Devices: Portable diagnostic equipment, wearables
Telecommunications: Base station RF front-ends

6. Leading Manufacturers and Products

Manufacturer	Product Series	Key Features
Texas Instruments	TPS7A49	150mA, 18V input, 75dB PSRR @ 1kHz
STMicroelectronics	LDL1117	1A output, adjustable via resistor divider
Analog Devices	ADP151	200mA, 25 A quiescent current, 200mV dropout
ON Semiconductor	NCP1117	1A, thermal overload protection, automotive-grade

7. Selection Guidelines

Key selection criteria:

Match input voltage range with power source (e.g., Li-ion battery requires 2.7V-5.5V)
Prioritize low dropout voltage for battery-powered devices
Calculate thermal dissipation (PD = (Vin-Vout) Iout)
Select appropriate PSRR for noise-sensitive applications (e.g., 60dB for audio circuits)
Consider package thermal resistance for high-current applications

Case Study: A wearable ECG monitor used Analog Devices ADP150 (150mA, 2.2V output, 15 A IQ) to achieve 14-day battery life.

8. Industry Trends

Emerging Ultra-Low Dropout (ULDO) designs with <50mV dropout voltage
Integration with PMIC digital interfaces (I2C/PMBus)
Advanced packaging: 3D TSV for improved thermal performance
Wide bandgap (GaN/SiC) pass transistors for high-voltage LVRs
AEC-Q100 compliant automotive LVRs with 150 C operating temperature