Low-Dropout Regulator with modest ripple and rugged performance in 180nm
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Low-Dropout Regulator with modest ripple and rugged performance in 180nm Presentation Transcript:
1.Low-Dropout Regulator with
modest ripple and rugged performance in 180nm
2.Presentation Outline
INTRODUCTION
LINEAR REGULATOR CONCEPTS
CIRCUIT IMPLEMENTATION
PERFORMANCE ANALYSIS
CONCLUSION
3.INTRODUCTION
Supplying and conditioning power are the most fundamental functions of an electrical system.
A loading application cannot sustain itself without energy, and cannot fully perform its functions without a stable supply
Transformers, generators, batteries, and other off-line supplies incur substantial voltage and current variations across time and over a wide range of operating conditions
High frequency switching circuits CPU and DSP circuits utilized in an application usually load it.
Solution for above mentioned problems is to use a power converter
4.LINEAR REGULATOR
CONCEPT OF LINEAR REGULATOR
5.LINEAR REGULATOR
Transient response of LDO
LDO provide power to low-voltage digital circuits operating under different modes of operation --voltage transients-cannot be handled by digital circuits
Factors affecting transient response of an LDO
The internal compensation of the LDO
The amount of output capacitance
The parasitics of the output capacitor
The faster local feedback n/w responds quicker to load changes than more complicated regulator loop
The additional loop has negligible effects on dc accuracy as its low frequency gain is kept well below that of the regulator
The additional loop also demand little to no current to have less impact on operational life of battery
6.LINEAR REGULATOR
REGULATING PERFORMANCE
LOAD REGULATION
Steady-state (dc) voltage variations in the output (?VOUT) resulting from dc changes in load current (?ILOAD) define load regulation(LDR) performance
Systematic input-offset voltages, which result from asymmetric currents and volt-ages in the feedback error amplifier, further degrade load-regulation performance
Even if the LDO were symmetric, its widely variable load would cause considerable voltage swings at internal nodes, subjecting some of the devices to asymmetric conditions
LINE REGULATION
Line regulation(LNR) performance is a dc parameter and it refers to output voltage variations arising from dc changes in the input supply
Power-supply variations affect the regulator in two ways
Directly through its own supply
Indirectly via supply-induced variations in reference VREF
7.LINEAR REGULATOR
PROCESS AND TEMPERATURE INDEPENDENT BIASING
The transconductance of MOSFETs determine performance parameters: small signal gain, speed and noise.
It is desirable to bias the transistors such that their transconductance is independent of process, supply voltage and temperature
8.Circuit Implementation
9.Conclusion
LDO regulator targeted for SOC applications
(optimized design for performance, board area, and cost)
LDO is stable for output current in the complete range from 0 to 100 mA
LDO with high regulation accuracy and fast transient response
10.LDO regulator targeted for SOC applications
(optimized design for performance, board area, and cost)
LDO is stable for output current in the complete range from 0 to 100 mA
LDO with high regulation accuracy and fast transient response
Download
Low-Dropout Regulator with modest ripple and rugged performance in 180nm Presentation Transcript:
1.Low-Dropout Regulator with
modest ripple and rugged performance in 180nm
2.Presentation Outline
INTRODUCTION
LINEAR REGULATOR CONCEPTS
CIRCUIT IMPLEMENTATION
PERFORMANCE ANALYSIS
CONCLUSION
3.INTRODUCTION
Supplying and conditioning power are the most fundamental functions of an electrical system.
A loading application cannot sustain itself without energy, and cannot fully perform its functions without a stable supply
Transformers, generators, batteries, and other off-line supplies incur substantial voltage and current variations across time and over a wide range of operating conditions
High frequency switching circuits CPU and DSP circuits utilized in an application usually load it.
Solution for above mentioned problems is to use a power converter
4.LINEAR REGULATOR
CONCEPT OF LINEAR REGULATOR
5.LINEAR REGULATOR
Transient response of LDO
LDO provide power to low-voltage digital circuits operating under different modes of operation --voltage transients-cannot be handled by digital circuits
Factors affecting transient response of an LDO
The internal compensation of the LDO
The amount of output capacitance
The parasitics of the output capacitor
The faster local feedback n/w responds quicker to load changes than more complicated regulator loop
The additional loop has negligible effects on dc accuracy as its low frequency gain is kept well below that of the regulator
The additional loop also demand little to no current to have less impact on operational life of battery
6.LINEAR REGULATOR
REGULATING PERFORMANCE
LOAD REGULATION
Steady-state (dc) voltage variations in the output (?VOUT) resulting from dc changes in load current (?ILOAD) define load regulation(LDR) performance
Systematic input-offset voltages, which result from asymmetric currents and volt-ages in the feedback error amplifier, further degrade load-regulation performance
Even if the LDO were symmetric, its widely variable load would cause considerable voltage swings at internal nodes, subjecting some of the devices to asymmetric conditions
LINE REGULATION
Line regulation(LNR) performance is a dc parameter and it refers to output voltage variations arising from dc changes in the input supply
Power-supply variations affect the regulator in two ways
Directly through its own supply
Indirectly via supply-induced variations in reference VREF
7.LINEAR REGULATOR
PROCESS AND TEMPERATURE INDEPENDENT BIASING
The transconductance of MOSFETs determine performance parameters: small signal gain, speed and noise.
It is desirable to bias the transistors such that their transconductance is independent of process, supply voltage and temperature
8.Circuit Implementation
9.Conclusion
LDO regulator targeted for SOC applications
(optimized design for performance, board area, and cost)
LDO is stable for output current in the complete range from 0 to 100 mA
LDO with high regulation accuracy and fast transient response
10.LDO regulator targeted for SOC applications
(optimized design for performance, board area, and cost)
LDO is stable for output current in the complete range from 0 to 100 mA
LDO with high regulation accuracy and fast transient response
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