overview of some power management issues - bgupedesign/slides/presentation2008.pdfzdc-dc...
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Prof. S. Ben-Yaakov, Overview [1]
Overview of Some Power Management Issues
Prof. Shmuel (Sam) [email protected]; 08-6461561; 054-4841947
Prof. S. Ben-Yaakov, Overview [2]
OUTLINE
• Power conversion principles• Conversion types: dc-dc, ac-dc, dc-ac• Typical areas of applicationTypical areas of application• Devices: switches, drivers, controllers, supervisory • Analog versus digital control
Prof. S. Ben-Yaakov, Overview [3]
Power Conversion Objective
PowerConversion
ElectricityType A
ElectricityType B
Uniderectional Power
OrBidirectional
Needed in all modern systemsExcept: incandescent lamps, heaters…
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Prof. S. Ben-Yaakov, Overview [4]
Conversion Typesby Functionality
AC-DC RectifierDC-DC Power converterDC DC Power converterDC-AC InverterAC-AC Cycloconverter
Prof. S. Ben-Yaakov, Overview [5]
Types of power Convertersby Technology
Linear power converters
Switch mode power converters– Switched inductor– Switched capacitor
Prof. S. Ben-Yaakov, Overview [6]
LINEAR REGULATORS
Why not Linear ?
3
Prof. S. Ben-Yaakov, Overview [7]
Linear Regulator
Vin Ro
IB
VoI1 I2
I II1 ≈ I2Power lost depends on voltage drop on regulatorRegulator needs a minimum of 3 volts (Low Drop Regulators (LDO) ~min(Vin-Vo)=1V or lessBut: Vin-Vo Variations ~3V
Prof. S. Ben-Yaakov, Overview [8]
Io
Io
VoRs
RLVin+-
Linear Power Conversion Systems
o
RsRso
o
in
o
oin
oo
in
o
VV1
1VV
VVV
IVIV
PP
+=
+==
⋅⋅
==η
o
Rs
o
Rs
VV
PowerOutputLostPower
PP
==
Prof. S. Ben-Yaakov, Overview [9]
Example
W100P;1V5V5
PP
losso
loss =→==
100W, 5V power supply
Assume: V3)VV( alminnooin ≈− V5)VV( maxoin ≅−
o
%50100200100% ≈⋅=η
%50% =ηThe problem is not It is 100W !
• Battery → efficiency• Line operation → heat dissipation• Cooling → size, expense
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Prof. S. Ben-Yaakov, Overview [10]
Switched Mode Converters
High efficiencySmall size
Source
L
CS
R
LoadSource Load
L, C: Reactive elementsS: “On” Resistance →0
“Off” Resistance →∞Low Losses→
⎭⎬⎫
Prof. S. Ben-Yaakov, Overview [11]
Switched Inductor ConvertersThe Most popular approachCharging and discharging and inductor
inV oC oR outVLin o
inV oC oR outV
LI
L
LI
Charging
Discharging
Prof. S. Ben-Yaakov, Overview [12]
Implementation
1Q
LinV
1D Q
2D
C R
outV
LinV
12Q
L
1D
2D
C R
outVON OFF
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Prof. S. Ben-Yaakov, Overview [13]
Dual Buck + LDO Regulator(FPGA and CPLD Application)
Prof. S. Ben-Yaakov, Overview [14]
Inside the TPS75003
Prof. S. Ben-Yaakov, Overview [15]
Inside the TPS75003 - LDO
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Prof. S. Ben-Yaakov, Overview [16]
Offline converter
Higher level of integration
Prof. S. Ben-Yaakov, Overview [17]
Disadvantagesof switch mode converters
More Expensive (in general, when comparable)NoisyLess ReliableSwitching Losses
500kHz
Switchingfrequency
Powerlevel
102W 104W 106W
100kHz
1kHz
Size
Switchingfrequency
200 kHz
Prof. S. Ben-Yaakov, Overview [18]
Parasitic losses– Conduction– Leakage
Switched Inductor Conversion Systems: Sources of Losses
– ESR
Magnetic (core) losses
Switching losses– Transistor switching – Diode reverse-recovery
7
Prof. S. Ben-Yaakov, Overview [19]
controlGSV
SV SVI
t
Switching lossesHard Switching
SI
dJswitchingP
t
t
Switching losses due to overlap Pd linear with fS !
Prof. S. Ben-Yaakov, Overview [20]
Soft Switching Real and pseudo
DVDI
dtdVD
DV
t
snubberdtdV
switchingsoft"True"
switchingsoft"Pseudo"
snubberdtdI
Prof. S. Ben-Yaakov, Overview [21]
Forward with Active Clamp
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Prof. S. Ben-Yaakov, Overview [22]
Asymmetrical Half BridgeSynchronous Rectification
SOFT SWITCHING
Prof. S. Ben-Yaakov, Overview [23]
Micrel 8Mhz Converter
Tiny inductor: 0.5 uH
Prof. S. Ben-Yaakov, Overview [24]
Micrel 8Mhz Converter with Standby LDO
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Prof. S. Ben-Yaakov, Overview [25]
Micrel 8Mhz Converter - Performance
Prof. S. Ben-Yaakov, Overview [26]
Reverse current at switch turn on
Vin
L
C R
Vx Vo
Diode Reverse Recovery
Prof. S. Ben-Yaakov, Overview [27]
Switched Capacitor ConvertersUsing capacitors as switching storage
inV oC oRC outV
Voltage polarity inverter (negative supply)
inV oC oRC outV
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Prof. S. Ben-Yaakov, Overview [28]
Calculation the energy lost when C is switched from V1 to V2
V1 V2C
;2
CVE21
1 = ;CVQ 11 = ;2
CVE22
2 = ;CVQ 22 =
);VV(2CEEE 2
22121C −=−=Δ
;CVCVQ 21−=Δ);VV(CQ 21−=Δ
( )( );2
VVVVCE 1221C
+−=Δ 2212V )VVC(VVQE
2−=⋅Δ=Δ
⎥⎦⎤
⎢⎣⎡ −+−=Δ−Δ 2
1221VC V
2VV)VV(CEE
2
[ ]2
VC2
VVVVCEE2
2121VC 2
Δ⋅−=
−−=Δ−Δ
Energy Lost
Prof. S. Ben-Yaakov, Overview [29]
Implications:
LV Co Ro
Switched inductor
“Lossless” process
CCo RoV
Switched capacitor
“Lossy” process
Prof. S. Ben-Yaakov, Overview [30]
Analog CaseLossless Switching Lossy switching
21 VV ≠
V1 V2V1 V2
I1 I2
IV
I2I1I1 I2
CI
dtdV =
21 II ≠
21 VV ≠ICVC
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Prof. S. Ben-Yaakov, Overview [31]
Switched Capacitor Converter
Prof. S. Ben-Yaakov, Overview [32]
Switched Capacitor Converter
Prof. S. Ben-Yaakov, Overview [33]
Packaging for Power Dissipation
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Prof. S. Ben-Yaakov, Overview [34]
Catalyst’s LED Driver
Prof. S. Ben-Yaakov, Overview [35]
Catalyst’s LED Driver -Efficiency
Prof. S. Ben-Yaakov, Overview [36]
Typical areas of application of Switched Mode PS (Buzzwords)
Off line - power factor, isolation, chargersTelecom - modular, PFC, intermediatebus cablebus, cableAutomotive Power over internet – PoEAuxiliary power supplyPortables - low voltage, single cell, chargers
13
Prof. S. Ben-Yaakov, Overview [37]
Typical areas of application of Switched Mode PS (Buzzwords)
Cont.
Lighting- ballasts, fluorescent, HID, LEDMotor-drive – inverter AC high voltageMotor-drive – inverter, AC, high voltage PC/Servers – VRM, VRDDistributed DC-DC – POLAlternative energy – Solar, wind, fuel cellsSupervisory
Prof. S. Ben-Yaakov, Overview [38]
Off Line
Prof. S. Ben-Yaakov, Overview [39]
Digital CameraOld Design
Dig_Cam_Marked.pdf
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Prof. S. Ben-Yaakov, Overview [40]
Maxim’s ASIC Solution
Maxim.pdf
Prof. S. Ben-Yaakov, Overview [41]
Freescale –Recent Product (Smart Mos)
Prof. S. Ben-Yaakov, Overview [42]
Devices: switches, drivers, controllers, supervisory
Power elementsPower elements Peripheral elements
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Prof. S. Ben-Yaakov, Overview [43]
Power Switches
BJT MOSFET IGBT
G
C
E
G
D
S
CB
E
BJT MOSFET IGBT
G
C
E
G
D
S
NPN
C
B
E
Prof. S. Ben-Yaakov, Overview [44]
Relatively slow (storage time)
Replaced by MOSFET or IGBT
BJT Drive problems
Still is use in lamp ballasts and in very high power applications (motor drive)
Prof. S. Ben-Yaakov, Overview [45]
Gate voltageNormal : 15V -15V
Power MOSFETs
n channel Internal diodes
p channel
Normal : 15V 15VLogic level: 5V -5V
n channel more popularless expensive
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Prof. S. Ben-Yaakov, Overview [46]
MOSFET → Rds(on) BJT, IGBT → VCE (sat)
Pd(MOSFET) →(I )2 Rds(on)
Characteristics of Active Switches
Pd(MOSFET) →(Irms) Rds(on) Pd( BJT, IGBT) → Iav VCE (sat)
SpeedMOSFET > IGBT > BJT
High Power → IGBT
Prof. S. Ben-Yaakov, Overview [47]
Other Switches
SCR - low frequency no forced turn off
MCT - SCR+FET input
GTO turn on and off; slow high currentGTO - turn on and off; slow, high current
Prof. S. Ben-Yaakov, Overview [48]
Cgs
CgdIg CdsRg
Vs
Driver Requirements
Q
Vgs
Vt
Qgs+Qgd
Qgs+Qgd
Miller capacitance15V
Q1 Q2 Q3
Capacitors are non-linear
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Prof. S. Ben-Yaakov, Overview [49]
t
VS
Vgs
15VDL
C RL
VoVin
RgIg
Driver Currents
t
t
Ig
VS Vgs
Prof. S. Ben-Yaakov, Overview [50]
Gate Drivers
High current into capacitive loadHi h lt 15V t i lHigh voltage - 15V typicalFast – tr 100nS and less Logic level inputHigh side
Prof. S. Ben-Yaakov, Overview [51]
BJT Driver (TI –Unitrode)
Totem pole
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Prof. S. Ben-Yaakov, Overview [52]
MOSFET Gate DriverMicrel
Prof. S. Ben-Yaakov, Overview [53]
TI BiCMOS Driver
Prof. S. Ben-Yaakov, Overview [54]
Driver Interfaces
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Prof. S. Ben-Yaakov, Overview [55]
High-Side Drive
The problem Solution #2 :Transformer couplingVb
G tRs
Problem1.Wide range of Don
VGS
Gatedriver
Prof. S. Ben-Yaakov, Overview [56]
Solution #2: Optical
VC - floating supplyDriver
VC
High-Side Drive – Cont.
Solution #3:Voltage offset
VC floating supply
Driver+VC
Re
Prof. S. Ben-Yaakov, Overview [57]
Voltage offset + floating C supply
D i
CRg
Re
Available for HB, FB
Driver
Internalcircuit
in+15V
20
Prof. S. Ben-Yaakov, Overview [58]
HB High Voltage Driver (IR)
600V
Prof. S. Ben-Yaakov, Overview [59]
Prof. S. Ben-Yaakov, Overview [60]
The Analog Controller Approach
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Prof. S. Ben-Yaakov, Overview [61]
Analog Controllers
Generating PWM signal Error amplifier DriverDriver
Prof. S. Ben-Yaakov, Overview [62]
Typical Analog Controller
Prof. S. Ben-Yaakov, Overview [63]
IC Converters
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Prof. S. Ben-Yaakov, Overview [64]
Embedded Power Switches Challenge
Linear analog plus switchesSingle versus multi-chipHVHV Obvious advantages to one package
Prof. S. Ben-Yaakov, Overview [65]
Efficiency
Prof. S. Ben-Yaakov, Overview [66]
CONTROL
Stabilizes and/or shapes the output signalStability and dynamics issuesAnalog and Digital control
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Prof. S. Ben-Yaakov, Overview [67]
Analog Controller
1R1CfR fC
outV
2ReV
PWMrefV
.Amp.Op
Prof. S. Ben-Yaakov, Overview [68]
VV
CompeV
rampV
PWM
Analog PWM Generator
rampVeV
t
t
V
PWM
SS f
1T =
Prof. S. Ben-Yaakov, Overview [69]
Analog ApproachPros– Low cost– Trivial to design– Fast– Parallel computation
E t i l t C t M d– Easy to implement Current Mode control
Cons– Many components– Analog– Difficult to change– Large PCB area
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Prof. S. Ben-Yaakov, Overview [70]
The Digital Approach
Prof. S. Ben-Yaakov, Overview [71]
Digital Control
1R
outV
]V)1n(V[a)1n(d)n(d refo1 −−+−=
1R
2RDPWM D/Amachinestate
orogramPrD
High sampling rate – high resolution
Prof. S. Ben-Yaakov, Overview [72]
Digital PWM (DPWM)
CounterogrammablePr
n
clk
PWM
Comparator
gisterReDRatioDutyn
nS
S f1T =
PWM
25
Prof. S. Ben-Yaakov, Overview [73]
frequencyswitchingfS −frequencyclockhigestfCLK −
%resolutionPWMsRe −
%100fsRe S=
DPWM Requirements
%100f
sReCLK
=
)bit10(%1.0sRekHz400f:Example
S
==
MHz40010104f
100sRe
ff
35CLK
SCLK
=⋅⋅=
=
Prof. S. Ben-Yaakov, Overview [74]
The Digital ApproachPros– Programmable– Stable– Potentially of small PCB size
ConsCons
– Expensive because:Needs very fast A/DHigh clock frequency for PWM resolutionDigital control requires higher bandwidthHeavy computation requires DSPComplex to designDifficult to implement Current Mode Control
Prof. S. Ben-Yaakov, Overview [75]
Requires new DPWM concepts
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Prof. S. Ben-Yaakov, Overview [76]
Performance of new DPWM
Prof. S. Ben-Yaakov, Overview [77]
Traditional Analog Power Supply (TI)
OutputV PFCFilter Bridge VV V
8 4
5 1
DC/DCC
Current/LoadSh i
DC/DC V
PFC C t lInrush/
H t l
I I I I
PFC C t lInrush/
H t l DC/DC
C tCurrent/Load
Sh i
UCD9K: System Simplification, Programmability in a Telecom Rectifier
•Multiple chips for control•Micro-controller for supervisory•Dedicated design
Aux P/S
ConverterControl
Multi-modePower control
MCU SupervisoryHousekeeping
Circuits
SharingControl
To Host
PFC Control
InterfaceCircuitMonitor(MCU?)
Hot-plug Control
PFC Control
InterfaceCircuitMonitor(MCU?)
Hot-plug Control
ConverterControl
Multi-modePower control
MCU SupervisoryHousekeeping
Circuits
SharingControl
Prof. S. Ben-Yaakov, Overview [78]
Digital Power Supply (TI)PFCFilter
BridgeVV
8 4
5 1
DC/DCI
Output
Aux P/S
Eliminate Components
Better Performance Across Corners
Failure Prediction
Reduce Manufacturing Cost
One Design, Multiple Supplies
27
Prof. S. Ben-Yaakov, Overview [79]
What is UCD9501
Prof. S. Ben-Yaakov, Overview [80]
Comparing Analog to DigitalCurrent Mode Control Example
D
1R
2R
oCQFF
L
OSC S
R
inVoutV
2SR
COMPfR fC
.Amp.Op
3R
refV
Cycle-by-Cycle protectionGood dynamics
Prof. S. Ben-Yaakov, Overview [81]
TI “Digital” Solution
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Prof. S. Ben-Yaakov, Overview [82]
TI’s Nixed Mode Solution
Prof. S. Ben-Yaakov, Overview [83]
iWatt
Prof. S. Ben-Yaakov, Overview [84]
Zilker Labs
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Prof. S. Ben-Yaakov, Overview [85]
Zilker Schematics
Prof. S. Ben-Yaakov, Overview [86]
Silicon Labs
Prof. S. Ben-Yaakov, Overview [87]
Silicon Lab
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Prof. S. Ben-Yaakov, Overview [88]
Systel
Prof. S. Ben-Yaakov, Overview [89]
Primerion
Prof. S. Ben-Yaakov, Overview [90]
Intersil - Primerion
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Prof. S. Ben-Yaakov, Overview [91]
Intersil - Primerion
Prof. S. Ben-Yaakov, Overview [92]
Volterra
Prof. S. Ben-Yaakov, Overview [93]
Volterra
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Prof. S. Ben-Yaakov, Overview [94]
Volterra
Prof. S. Ben-Yaakov, Overview [95]
Volterra
Prof. S. Ben-Yaakov, Overview [96]
Power One
33
Prof. S. Ben-Yaakov, Overview [97]
Potentia
Prof. S. Ben-Yaakov, Overview [98]
Potentia
Prof. S. Ben-Yaakov, Overview [99]
Summit Microelectronics
SMB112- Five-Channel Digitally Programmable White LED and TFT-LCD Power Manager
34
Prof. S. Ben-Yaakov, Overview [100]
Summit MicroelectronicsThe Details
SMB112EV.pdf
Prof. S. Ben-Yaakov, Overview [101]
Summit Microelectronics
Prof. S. Ben-Yaakov, Overview [102]
IR Multi-Phase Solution
35
Prof. S. Ben-Yaakov, Overview [103]
IR Building Block
Prof. S. Ben-Yaakov, Overview [104]
IR3623/IP2003