PMIC - Voltage Reference

Part Number	Description / PDF	Quantity
TLV431BSNT1G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 16V 0.5% 5TSOP	268051000
KA431AZBU Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 1% TO92-3	1000010000
TLV431ASN1T1G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 16V 1% SOT23-3	2147483647
KA431SLMF2TF Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 0.5% SOT23F-3	2786
NCP431BCSNT1G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 0.5% SOT23-3	282530000
NCP431ACSNT1G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 1% SOT23-3	2757
LM431SBCM3X Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 1% SOT23-3	2147483647
KA431AZTA Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 1% TO92-3	5047
TL431CDMR2G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 2.2% MICRO8	280016000
TL431AILPRPG Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 1% TO92-3	883
SC431AVSNT1G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 1% SOT23-3	45
TL431AIDG Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 1% 8SOIC	2709996
NCP431AVSNT1G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 1% SOT23-3	2797
LM431SBCM32X Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 1% SOT23-3	370127000
LM285D-1.2G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 1% 8SOIC	5850
LM385BZ-1.2G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 1% TO92-3	225
TL431CDR2G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 2.2% 8SOIC	698
TL431BCLPG Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 0.4% TO92-3	471
SC432BVSNT1G Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 0.5% SOT23-3	0
TL431CDG Sanyo Semiconductor/ON Semiconductor	IC VREF SHUNT 36V 2.2% 8SOIC	105315680

PMIC - Voltage Reference

1. Overview

Voltage references are precision analog circuits that generate stable and accurate DC voltage levels. As critical components in Power Management Integrated Circuits (PMICs), they serve as calibration standards for analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and power monitoring systems. Their stability against temperature variations, process shifts, and supply voltage fluctuations ensures measurement accuracy and system reliability in modern electronics.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Bandgap Reference	Temperature-compensated design using bipolar transistor characteristics	General-purpose ADC/DAC calibration
Zener Reference	High-voltage stability through reverse breakdown characteristics	Industrial power supplies, test equipment
LDO Voltage Reference	Low dropout voltage with high PSRR performance	Battery-powered devices, portable instruments
High-Precision Reference	Sub-0.1% initial accuracy with ppm-level temperature drift	Medical imaging systems, precision sensors
Programmable Reference	Digital control of output voltage via I2C/SPI interfaces	Adaptive power systems, FPGA voltage scaling

3. Structure and Composition

Typical voltage reference architecture includes: - Primary reference source (bandgap or Zener diode) - Operational amplifier for voltage buffering - Temperature compensation circuitry - Output driver stage - Protective elements (ESD protection, current limiting) Fabricated using CMOS/BiCMOS processes, housed in SC70, SOT23, or TSSOP packages with 3-8 pins. Advanced designs integrate digital calibration registers and thermal shutdown functions.

4. Key Technical Specifications

Parameter	Description	Importance
Initial Accuracy	Voltage deviation at 25 C ( 0.02% to 1%)	Determines system calibration baseline
Temperature Coefficient	Drift rate over temperature range (1-100ppm/ C)	Affects measurement stability
Output Noise	RMS noise voltage in 0.1-10Hz band (5 V to 100 V)	Impacts ADC/DAC resolution
Load Regulation	Voltage change with load current (0.01%/mA)	Ensures stability under dynamic loads
Line Regulation	Voltage change with supply voltage (0.05%/V)	Maintains accuracy with supply variations

5. Application Areas

Communication: 5G base stations, optical transceivers, RF test equipment
Consumer: Smartphones, wearables, battery management systems
Industrial: Process control sensors, PLC modules, precision instrumentation
Automotive: Battery management systems (BMS), ADAS sensors, engine controllers
Medical: MRI systems, portable diagnostic devices, patient monitors

6. Leading Manufacturers and Products

Manufacturer	Product Series	Key Features
TI	LM4040/LM4050	0.1% accuracy, 50ppm/ C tempco, 50mA output
Analog Devices	ADR45xx	0.02% initial accuracy, 3ppm/ C drift
Maxim Integrated	MAX6126	Series voltage reference with enable pin
STMicroelectronics	LN3480	Low-power consumption (380nA IQ)
ON Semiconductor	NCP100	Cost-effective solution for 12-bit ADCs

7. Selection Guidelines

Key selection criteria: - Required accuracy class (0.02% vs 1%) - Operating temperature range (-55 C to +125 C) - Power supply constraints (voltage headroom, quiescent current) - Package size and thermal dissipation capability - Long-term stability requirements (aging effects) - Cost vs performance trade-offs (e.g., programmable vs fixed) Example: For a 16-bit industrial ADC system, select a reference with <5ppm/ C tempco and <1 Vpp noise.

8. Industry Trends

Nanometer process integration enabling sub-1V references
Development of chopper-stabilized references for ultra-low drift
Increase in digital programmable references with I2C interfaces
Advancements in radiation-hardened references for aerospace
Reduced package sizes (0.65mm x 1.0mm WLCSP)
AI-enhanced self-calibration algorithms in smart references