Transcript
Power Electronic Systems & Chips Lab., NCTU, Taiwan
Switching Power Supplies for the PC
電力電子系統與晶片實驗室 Power Electronic Systems & Chips Lab.
交通大學 • 電機控制工程研究所
台灣新竹‧交通大學‧電機控制工程研究所‧電力電子實驗室~鄒應嶼 教授
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Switching Power Supplies for the PC Switching Power Supply
Line (hot) Neutral Earth Safety: must be connected
PC Mother Board 12 Vout
PFC Diode
EMI
3.3V
SMPS MOSFET
SMPS controller
Bias output SMPS regulator
5V
Post regulator
Supervisory
PFC controller
AGP
12V
5 Vout 3.3 Vout
filter
case
Output circuitry
PCI
12V 3.3V
12V
VRM VRM
1.5V
1.2V
Memory CPU
Output rectification
High Efficiency Fast Response DC-DC Converter
In considerations of safety, electrical shock due to leakage current or lighting, case must be grounded (connected to Earth)!
台灣(採用美規)使用的主要家用插座/插頭型式 NEMA 1–15規格（北美洲15 A/125 V非接地用） NEMA-1插頭與NEMA-1及NEMA-5插座相容。NEMA-1為非接地型，NEMA-5 則為接地型；插頭有兩個平行刀片接點。早期版本為非極性，但在今日多數的 插頭則以較長之刀片接點為中性點，以插入插座上較寬之中性插槽作為極性之 分。（非極性之AC轉接頭則為常見的例外）。 在美國與加拿大，於新建築物中使用非接地型NEMA-1插座是不允許的，但仍 可在舊式建築物中找到。但可依據各地法令允許更換為NEMA-1插座。
NEMA 5–15規格（北美15 A/125 V接地用） NEMA 5-15規格是所有北美國家（加拿大、美國和墨西哥）的標準。5-15規格 插座也被使用於中美洲、加勒比海地區、南美洲北部（哥倫比亞、厄瓜多、委 內瑞拉和巴西）、日本、臺灣和沙烏地阿拉伯。 在美國某些地區，規定於新建建築物的插座上需安裝防護殼，以防止異物插入。
台灣使用的家庭110V牆壁單相交流電插座之額定電流為15 A (RMS). 在最佳情況(pf=1.0)，一組迴路最高輸出功率為110x15A = 1650 Watt. 若功率因數為0.7，則最高輸出功率為1650 x 0.7 = 1155 Watt. 3/22
NXP (Philips) GreenChip Solution for PC Power Supply NXP PFC Controller
TEA 1781/82; Synchronous Rectification, Housekeeping and Standby control
TEA 1771; Active Reset Forward topology
GreenChipPC exceeds Climate Savers Computing Initiative’s requirements for July 2009
NXP MOS FET’s 4/22
Functions and Requirements Common to Most DirectOff-Line Switchmode Power Supplies
Chapter 4 Faraday Screen
Input Transient Voltage Protection Electromagnetic Compatibility (EMC) Differential-Mode Noise Common-Mode Noise Faraday Screens Input Fuse Selection Line Rectification and Capacitor Input Filters Inrush Limiting Start-Up Methods Soft Start Start-Up Overvoltage Prevention Output Overvoltage Protection Output Undervoltage Protection Overload Protection (Input Power Limiting) Output Current Limiting
Switchmode Power Supply Handbook, Keith Billings and Taylor Morey, McGraw-Hill Education, 3rd. Ed., October 12, 2010.
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Functions and Requirements Common to Most DirectOff-Line Switchmode Power Supplies ..
Base Drive Requirements for High-Voltage Bipolar Transistors Proportional Drive Circuits Anti-saturation Techniques Snubber Networks Cross Conduction Output Filtering, Common-Mode Noise, and Input-to-Output Isolation Power Failure Signals Chapter 17 Anti-Saturation Techniques Power Good Signals Preventing “hard” saturation of bipolar transistors to Dual Input Voltage Operation improve turn-off performance Power Supply Holdup Time Keep bipolar transistor in a quasi-saturated state Synchronization Dynamic control of the gate drives is required Anti-saturation circuits are often combined with External Inhibit proportional drive techniques Forced Current Sharing More details: Part 1, Chap. 17 ANTISATURATION Remote Sensing TECHNIQUES FOR HIGH-VOLTAGE TRANSISTORS P-Terminal Link Low-Voltage Cutout Voltage and Current Limit Adjustments Input Safety Requirements 6/22
Power Supply for PC Mother Board PC Mother Board 3.3V
+/- 12V
PC Power Supply
AC
5V
5V
3.3V
AGP
12V
PCI
12V 3.3V
12V
VRM VRM
1.5V
1.2V
Memory CPU
7/22
Powering PC Processor Power Delivery
AC
Power Supply
PC Mother Board
12V
3.3V 12V
AGP
5V
5V 12V
PCI
3.3V
3.3V 12V
VRM VRM
2.5V 1.7V
Memory CPU 8/22
Functional Block Diagram of a Switching Power Supply Line input
60 Hz
20-200 KHz
120 Hz
output DC
High frequency inverter Load
Source
Input EMI filter
PFC converter and filter
output rectifier and filter
PWM
Feedback Sensing, reference, and Isolator
COMP
PFC Controller OSC
Output EMI filter
REF
PWM Controller
A power supply is a power conversion and control processor. 9/22
Typical Block Diagram of an ATX Power Supply Output circuitry 12 Vout
PFC Diode
5 Vout
filter PFC controller
SMPS MOSFET
3.3 Vout Post regulator
SMPS controller
Bias output
Supervisory
EMI
Output rectification
SMPS regulator
ATX12V Power Supply Design Guide (Copyright @ 2004, INTEL)
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Power Supplying for Desktop PC and Servers
Typical Specifications:
11/22
ATX Power Supply for PC There are 3 types of power supply in common use: AT Power Supply - still in use in older PCs. ATX Power Supply - commonly in use today. ATX-2 Power Supply - recently new standard. The voltages produced by AT/ATX/ATX-2 power supplies are:
+3.3 Volts DC (ATX/ATX-2) +5 Volts DC (AT/ATX/ATX-2) -5 Volts DC (AT/ATX/ATX-2) +5 Volts DC Standby (ATX/ATX-2) +12 Volts DC (AT/ATX/ATX-2) -12 Volts DC (AT/ATX/ATX-2)
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ATX Power Supply Pinouts
note: The pinouts above relate to the connectors not the sockets. note: To power up an ATX or ATX-2 PSU for testing, short pin 14 (PS_ON) with one of the grounds. 13/22
Typical Specifications of an ATX Power Supply
ATX12V Power Supply Design Guide (Copyright @ 2004, INTEL) 14/22
Abbreviated Specifications for a 250W ATX SPS
Input Voltage: 90 – 265 Vac, 47-63 Hz Input Current: 5A maximum. Input Harmonics: Meets IEC1000-3-2 for all load conditions. Hold-up Time: 20ms minimum. Inrush Current: Less than the ratings of input components. Line regulation and load regulation: <5% Outputs (example of 250W ATX power supply): Output current (A)
Output Voltage (V)
Min.
Max.
12
0
10
5
0.3
25
50
3.3
0.3
16
50
5
0
0.3
100
12
0
0.8
120
5 SB
0
1.5
Peak current (A)
Ripple & noise (mVpp)
12
120
2.5
50 15/22
Typical Power Distribution for a 250 W ATX12V Configuration and Cross Loading Graph Max. Current (amps)
Peak Current (amps)
+12 V1DC(1)
1
8
9
+12 V2DC(1,2)
1
13
16.5
+5 VDC
0.3
12
+3.3 VDC
0.5
14
-12 VDC
0
0.3
+5 VSB
0
2.5
Output
3.5
250W Cross Regulation (5V rail+3.3V rail vs. 12V)
120 5V+3.3V power (watts)
Min. Current (amps)
Combined Power (5V rail+3.3V rail)
100 80 60 40 20 0 0
50
100
150
200
250
12V power (watts) Note: Total combined output of 3.3 V and 5 V is ≤ 115W Peak currents may last up to 17 seconds with not more than one occurrence per minute (1) 12V1DC and 12V2DC should have separate current limit circuits to meet 240VA safety requirements. (2) 12V2DC supports processor power requirements and must have a separate current limit and provide 16.5A peak current for 10 ms; minimum voltage during peak is > 11.0 VDC
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General Power Supply Specs. Contain:
Efficiency: 75% minimum at full load, 120 Vac input Temperature: Storage -20°C to +85°C, Operating 0°C to +50°C. Operating Range: See derating curve below Reliability: The power supply reliability, when calculated by MIL-HDBK-217; latest revision, are exceed 100,000 hours with all output at maximum load and an ambient temperature of 25℃.
Storage: -40°C to +85°C 100 W
200 LFM forced air cooling
LFM: Linear Feet per Minute
80 W
Natural convection cooling
0C
10C
20C
30C
50 W 40 W
40C
50C
60C
70C
Temperature Derating
EMI Filter Design EMI filter
Gate Drive Design PFC diode
NCP1653 PFC controller
Clamp MOSFET Driver
Power Quality
NCP1280 SMPS controller
Power MOSFET
Transformer Design
Snubber Circuit
Inductor Design
Active Clamping
Output Filter Design
Synchronous rectifiers 12 Vout 5 Vout
SMPS MOSFET
NCP4330 3.3 Vout post regulator
TL431
Bias output
PWM Controller Post Regulator
Power Management Power Monitoring Startup Control Protection
PFC Control Primary-Side Control
NCP112 Supervisory IC
Green-Mode SPS Design
17/22
NCP1014 SMPS regulator
output rectification
Current Sensing Opti-Coupler Feedback
TL431
Linear Regulator Control Loop Design
200W ATX PC POWER SUPPLY (without PFC) 1998
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2009-02-04：安森美80 PLUS銀級效能255W ATX電源參考設計
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Recommended Reading: PWM SPS
Design flow for a PWM switching power supply Power Supply Cookbook, Marty Brown, EDN Series for Design Engineers, 2001
Study Map of PWM Switching Power Supplies Vin(DC) Input
RFI filter and surge suppression (Appendix E)
Input rectifiers and filtering (Sec. 3.12)
Vout(DC) Transformer (Sec 3.5.2~4)
Rectifiers and filters (Sec. 3.6)
Output
Voltage feedback circuit (Sec. 9)
Power switches (Sec. 3.7) Start-up, IC supply & drive bias circuit (Sec. 3.10)
Protection circuits (Sec. 3.11)
Controller (Sec. 3.8)
Ground
Power Supply Cookbook, Marty Brown, EDN Series, 2001.
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