mWSaver™ Technology from Fairchild for
Reducing Standby Power Consumption
Lawrence Lin
May. 10 ,2011
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Agenda
• Advanced Power Saving Technology
• mWSaver™ Technology Roadmap
• Minimizing Standby Power by Optimizing Passive Components
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Key Growth Area of AC-DC Power
Supplies – Mobile Communication
Worldwide Power Supply Market
20000
18000
Units in Millions
16000
14000
12000
UPS
10000
INVERTERS
8000
BATTERY CHARGERS
6000
DC-DC
4000
AC-DC
• Key growth area will be
communications, driven
by mobile phones
• A 60% increase in just
four years
2000
0
2009
2010
2011
2012
2013
2014
Years
Source: Selantek Power Supply Report 2010
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Market Trend for Smart Devices
Unit：%
100
US Smart Phone Penetration
Feature Phone
90
Smart Phone
80
70
60
50
40
30
20
10
0
Note: Percentages may not total 100% because of rounding
Source: Forrester Research eReader Forecast, 2010 to 2015 (US)
Source：Nielson (2010/11)
• If we take US market as an example :
•
•
•
Smartphone and feature phone shipments will meet the cross point in US market
Smartphone shipment will increase sharply in the coming years, but feature phone
shipment will continuously drop
Among various PCs, the Tablet will have the highest growth rate
• The growth trend for smart devices is spreading to the whole world
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Constantly drawing Power –
Standby Power Loss
• Today, there are between 6 and 10 billion power supplies in use
worldwide which are typically plugged in and unused for 20 hours
a day, while constantly drawing power.
• A typical American home has 40 products constantly drawing
power (standby power). Together these amount to almost 10% of
residential electricity use. Figures for most developed countries
also show 5% to 10% of power consumption going to standby
power.
• Standby power use is roughly responsible for 1% of the global
CO2 emissions
• These numbers illustrate the growing concern of energy waste and
illustrate the profound possible impact of reducing standby power.
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Design Challenge for Smart
Device Chargers Today
• Lower Standby Power：solution to comply to future energy
efficiency regulations
• Current Enery Star 5 Star Level calls for
standby power < 30mW
• More stringent standards are expected to be
in place in the next two years, and some
applications have been preceding at a faster
pace.
• Smaller form factor
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Advanced Power Saving Technology
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The Leader in Ac-Dc Converter ICs
Green PWM ICs
Green FPS – Fairchild Power Switchs
mWSaver™
PFC, and Combo (PFC + PWM) ICs
inside
Resonant Control ICs and Power Switches
Synchronous Rectifier Controllers/Drivers
BLDC Controllers
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Benefits from Standby Power Saving
Potential Energy Savings with
conversion to FSC IC
Why is this important?
Current specs for cell phone chargers
require <300mW under standby
conditions
•
Most chargers have standby power in
the range of 50-100mW
•
FSC launched a <10mW solution
•
Typical chargers are in standby >20
hours every day
•
More than 1B chargers are sold per
year
FSC cuts standby
power from 100mW to
<10mW. This will save
0.5M Barrels of Oil/Year
further
At this rate, the energy
saved would equal more
than 1M Barrels of Oil/Year
6,000
Energy Savings/Day (MWh)
•
5,000
4,000
3,000
2,000
1,000
35
100
300
Standby Power of Comparison Supply (mW)
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Losses at No Load
• Switching Loss
1
2
× COSS × VDS × fSW
2
• Conduction Loss
V2
R
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Reducing Standby Power –
Burst Mode(I)
• In Burst Mode, MOSFET Loss, and Snubber Loss are highly
related to bursting frequency.
• Voltage level on FB pin (VFB) is the key factor to adjust PWM
burst period. Therefore, we can control the VFB to determine the
bursting frequency.
VFB_H
• The figure on the right
shows the modulation
method in Burst Mode.
Extreme low standby power
loss under no load could
achieved by cotrolling the
period of burst mode.
VFB
VFB_L
Gate
TSW_OFF
TSW_ON
TBurst
Zoom in
Gate
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Fsw=85KHz
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Reducing Standby Power –
Burst Mode(II)
• IC Operation Loss amounts to 15% of the total standby power loss.
• As the figure below, Fairchild solution provides Very Low
operating current while in Burst Mode. It significantly reduces the
IC Operation Loss.
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mWSaver™ Technology for
Smart Devices
• mWSaver™ technology is an optimized combination of process and circuit
technologies that will be embedded in key power adapter components
• All components with the mWSaver technology brand designation will feature
the industry’s lowest standby/no-load power consumption per component
• mWSaver Technology Solution for Smart
Devices, FAN302HL:
• PWM controller that achieves under
10 mW standby power.
• Suitable for application from 5 W~15 W,
the power range for Smart Devices (smart
phones and tablet PCs).
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FAN302HL Blocks and Features
•
HV startup
HV
protection
Latch-off
VDD
Protection
OVP
Soft
Driver
S
OVP
VDD-O VP
Q
OSC with
Frequency
Hopping
Internal
Bias
3
2
Constant
Current
Controller
16V/5V
Constant
Current
Regulation
EA_I
•
Peak
Detector
Blanking
Circuit
UVLO
(
)
•
•
CV/CC control
VDD- LH
VDD
15V
R
Latch-Off
release
GATE
Frequency hopping
8
OTP
VS OVP
•
•
Constant-current (CC) Control Without
Secondary-feedback Circuitry
High voltage start up
Ultra low standby power loss : <10mW
1
EA_V
OFF time
Modulation
CS
•
Slope
Compensation
Tdis
VS OVP
S/H
4
•
•
6
FB
3V
GND
5
5V
S/H = Sample and Hold
Green
Mode
Controller
3R
VS
•
•
R
•
•
•
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VS OVP(2.8V) with Latch Mode
Fixed PWM Frequency at 85kHz with
Frequency Hopping to help EMI
CC Regulation With Linear Switching
Frequency Decreasing
CV Regulation With Fixed Switching
Frequency to Burst Mode
Cycle-by-cycle Current Limiting
VDD Over-voltage Protection with Auto
recovery(27V)
VDD Under-voltage Lockout (UVLO, 5V)
Gate Output Maximum Voltage Clamped at
15V
Fixed Over-temperature Protection
SOP-8 Package
OTP with Latch Mode
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No Load Standby Power
• FAN302HL 85kHz 5W(5V/1A)- EI12 Schematic
Standby Power analysis : 9.07mW (Calculation result)
MOSFET loss
2nd FB loss
IC operating loss
Snubber loss
Others
Standby Power Measurement
0A
90Vac
115Vac
230Vac
264Vac
6.6mW
6.6mW
7.9mW
8.7mW
Fsw : 85Khz, FBurst-mode : 50Hz, Ton-min : 0.8uS
FAN302HL
30units result
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Other Benefits from FAN302HL
VS OVP for safer system together and BOM saving
Good CV dynamic
CV ±5% vs. CC ±10%
Ripple < 100 mV
Efficiency: Meet Energy Star® EPS v2.0 (Level V)
CV & CC
± 5%
± 10%
CC from PSR
CV from SSR
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Meeting Typical Application Specs
with FAN302HL
5 W Solution
Applications
Some Key
Specifications
10 W Solution
• Smart phone charger
• 5 V, 1 A
• Tablet PC charger
• 5 V, 2 A
• < 10 mW Stand-by Power
• < ±2.5% in CV
• < 100 mVp-p
• > 74% @ 100 VAC
• < 6 V OVP
• < 10 mW Stand-by Power
• < ±2.5% in CV
• < 100 mVp-p
• > 80% @ 100 VAC
• < 6 V OVP
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Technology Roadmap
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Technology Roadmap
500 mW
200 mW
100 mW
60 mW
40 mW
20 mW
10 mW
@ 230 VAC, 65 W / 19 VOUT
Frequency Hopping
VGS
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Technology Roadmap
500 mW
200 mW
100 mW
60 mW
40 mW
20 mW
10 mW
@ 230 VAC, 65 W / 19 VOUT
AC Voltage
VAC
VDC
Switching
Power Stage
Bridge Diodes
No HV switch to open startup
loop, it will continuously
contribute loss.
IST
VIN
PWM
Controller
VDD
AC Voltage
Switching
Power Stage
Bridge Diodes
IST
Turns off the switch
after IC startup.
HV
VDD
HV Switch
20
IHV
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Power Loss Breakdown in FAN6754
Secondary conduction loss
15 mW
30 mW
4 mW
EMI Bleeding Resistor Loss
17 mW
10 mW
Feedback loop Loss
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Technology
ZFB Switching
VFB
Vo
RFB
FB
Rb
VF
R3
CFB
R1
C1
KA431
22
R2
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Mass Prod.
Technology Roadmap
500 mW
200 mW
100 mW
60 mW
40 mW
20 mW
Developing
Planning
10 mW
@ 230 VAC, 65 W / 19 VOUT
FAN6755
FAN6754
SG6742
SG6741
SG5841
ZFB Switching
Idd 2.0 mA / 0.6 mA
Idd 1.7 mA / 1.2 mA
Idd 3.7 mA
700V HV JFET Startup
Off-Time Modulation
Burst Mode Operation
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FAN6755 No Load Power Saving
16 V / 2 A, 5 V / 4 A LCDM Demo Board
No Load Power Saving
Input Voltage
Input Wattage
Output Voltage(V)
90 V / 60 Hz
17.6 mW
4.86 V
12.41 V
115 V / 60 Hz
19 mW
4.86 V
12.41 V
230 V / 50 Hz
28 mW
4.86 V
12.41 V
240 V / 50 Hz
32 mW
4.86 V
12.41 V
264 V / 50 Hz
56 mW
4.85 V
12.42 V
Spec.
240 VAC
Efficiency
Input Voltage
Input Wattage
Output Watt. Efficiency (%)
115 V / 60 Hz
51.32 W
42.48 W
82.77%
230 V / 50 Hz
51.17 W
43.24 W
84.50%
Spec.
> 80%
FAN6755
5 VOUT / No load & 16 VOUT / No load
5 VOUT / 6.9 mA & 16 VOUT / No load
Input Voltage
Input Power
5 VOUT
16 VOUT
Input Voltage
Input Power
5 VOUT
16 VOUT
264 V / 50 Hz
56 mW
4.85 V
12.42 V
264 V/50 Hz
89 mW
4.41 V
13.6 V
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How Low Can the Power Savings Be ?
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Technology
Ax-Cap™ Technology
L
N
VAC
VHV
HV
R2
V SAMPLE
JFET
VTH
VHV
Sampling
VHV
1
UVLO
Unplug Detect
Circuit
VDD
M2
40ms
Turn off PWM
& pull VDD to UVLO
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Brown-out Protection
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Vdd Operation- PSR Mode at No Load
UVLO
PSR Mode
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Mass Prod.
Technology Roadmap
500 mW
200 mW
100 mW
60 mW
40 mW
20 mW
Developing
Planning
10 mW
@ 230 VAC, 65 W / 19 VOUT
FAN676x
2013
FAN676x
2012
FAN675x
2011
FAN6755
FAN6754
SG6742
2003
SG5841
SG6741
New mWSaver™ Technologies
Ax-Cap™
ZFB Switching
ZFB Switching
Idd 2.0 mA / 0.6 mA
Idd 1.7 mA / 1.2 mA
Idd 3.7 mA
700V HV JFET Startup
Off-Time Modulation
Burst Mode Operation
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FAN675X/6X
Value Proposition
• Leading PWM solutions in Efficiency, Power Saving and Feature Integration
GATE
GND
Common Features
• Green Technology ( all patented )
FB
• Ax-CapTM Technology
NC
• PSR Mode to drop Vo at no load
VDD
FAN676x
SENSE
RT
HV
• Zfb switch during PSR mode
• Linear frequency decrease with load decrease
• Burst mode at mini load without acoustic noise
No Load Input Power
• 700V JFET HV process
• Patented Asynchronous Jitter for EMI reduction
230V/50Hz
13mW
• Two level UVLO for low input output during SCP
264V/50Hz
18mW
• Line Compensation for precise OPP
• Protection: OVP, OCP, OLP, OPP, Brown out , Latch or Auto optional
• Patented Sense Short Circuit Protection (SSCP) to pass LPS test
•Surge pass 6KV, ESD HBM > 5KV
65W/19V Board
• Fixed freq. at 65KHz /100KHz
• Green compound package for halogen free
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SR Solution- FAN6204F
Spec. Modification of FAN6204F
FAN6204
FAN6204F
Vdd-on
4.8V
14V
Vdd-off (UVLO)
4.5V
12V
Idd-op
7mA
7mA
Idd-green
800uA
150uA
Idd-UVLO
None
1~1.5uA
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mWSaver™ Technology – Provides
You the Best-in-Class Standby Power
• FAN302HL’s lowest standby power in smart device charger
application marked the beginning of mWSaver Technology.
• mWSaver™ technology is being designed into a series of SMPS
ICs that will be released throughout 2011. Included will be
additional PWMs, PFC, PFC/PWM combo controller, Fairchild
Power Switch and a Synchronous Rectifier controller. These will
enable the 30 mW and even 10 mW standby power ratings in
demand for various adapter power ranges.
• By developing solutions like mWSaver™ technology and the
FAN302HL, Fairchild enables engineers to drive innovation in
their designs for maximum performance, simplified design and
reduced bill of materials costs.
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Minimizing Standby Power by
Optimizing Passive Components
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Neutral
Live
Losses of passive components analysis
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Discharge Resistor at Input Filter
Criteria to check primary voltage(UL60950).
“Time constant not exceeding 1 second”
means that
within one second, voltage should
be decreased to 37% of nominal quantity
For example, RDISCHARGE=1MΩ, CE=322nF
Ploss =
230Vac 2
= 52.9 mW
1MΩ
τ = 1MΩ ⋅ 322 nF = 0.322 sec
Balance between power loss and discharge time is needed.
RDISCHARGE
PLOSS @230Vac
τ @CE=322nF
1 MΩ
52.9mW
0.322sec
2 MΩ
26.5mW
0.644sec
∆18.7mW
3 MΩ
17.6mW
0.966sec
∆27.6mW
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Remark
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Clamp Losses in Steady State
RCD snubber loss.
SN
PLOSS
= VCL ⋅
i peak ⋅ t s
2
⋅ fsw =
VCL
1
2
⋅ Llk ⋅ i peak
⋅
⋅ fsw
VCL − nVo
2
Snubber block is assumed as a constant voltage source of VSN.
E=
1
2
⋅ LLK ⋅ i peak
⋅ fsw
2
To reduce snubber loss, 2 available major factors
- VCL
- fSW
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Energy to Recharge Capacitor
Additional recharge discharging loss.
SN
PLOSS
_ ADD =
1
2
⋅ Csn ⋅ VCL
⋅ fsw _ bundle
2
Transient Voltage Suppressor(TVS)
Clamp voltage
VCL[20V/div]
Switch voltage
VDS [100V/div]
37
t [5µs/div]
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Auxiliary Winding Circuit for Self
Biasing
1N4007
Energy transfer to
Vcc input
UF4004
Energy transfer to
Vcc input
Back to primary
or output load
1N4007/UF4004
Vcc
Idiode
Vanode
Vcathode
Vande[5V/div]
Idiode[0.5A/div]
I5V[2.0A/div]
Vds[100V/div]
t [2µs/div]
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Electrolytic Capacitors:
Impedance Characteristics
10mm
10mm
21mm
25mm
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Electrolytic Capacitors: ESR Affect
ESR loss calculation.
DC link
2
ICAP
IDRAIN
CAP
PLOSS
FPSTM
Vstr
IDRAIN [0.5A/div]
Drain
Vcc
FB GND
 CAP
1
D  ⋅ ESR
=  I Peak

3 

2

6 µs 1 
= 5 A ×
× 139 mΩ = 3.5 mW @ KMG


µ
2000
s
3


2

6 µs 1 
= 5 A ×
× 25 mΩ = 0.63 mW @ NXB


µ
2000
s
3


ICAP [1A/div]
t [2µs/div]
When multiple capacitors are used in parallel…
High ESR capacitors in parallel
Low ESR capacitors in parallel
VDS [100V/div]
VDS [100V/div]
80Hz
638Hz
t [500µs/div]
t [5ms/div]
t [20µs/div]
40
t [50µs/div]
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Dummy Load Effect
Vo_14V
20V
Io_14V
0mA
3mA
10mA
21V limit?
16V
12V
Io_5V
0.5A
1.5A
2.5A
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Minimize Power Loss Due to
Feedback Circuit
Unwanted dummy load.
Different CTR can decrease needed current.
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Increasing Feedback Resistors
60
Control-to-output
Compensator
40
Gain (dB)
T (Closed loop gain)
20
fCROSSOVER
0
-20
-40
10
100
1000
10000
100000
frequency (Hz)
60
Control-to-output
RF can be another choice.
Compensator
40
Gain (dB)
T (Closed loop gain)
20
fCROSSOVER restored.
0
-20
-40
10
100
1000
10000
100000
frequency (Hz)
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Experimental Result: Comparison
Input power difference between non
optimized and optimized SMPS
Light load power consumption
with optimized SMPS
Load condition
600
Vo(V)
5
Io(mA)
0
(mW)
0
85Vac
36
115Vac
36
230Vac
43
265Vac
46
300
5
5
5
10
25
50
67
93
69
94
77
102
80
105
200
5
15
75
125
127
135
138
5
5
5
20
25
30
100
125
150
156
188
212
158
189
215
166
198
224
171
202
228
5
35
175
245
246
256
261
5
40
200
276
277
287
294
Non optimized SMPS
Optimized SMPS
500
Input power [mW]
Input power(mW)
400
100
0
0
25
50
75
100
125
150
175
200
Output power [mW]
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The Right Technology for Your Success™
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