TND320/D Rev. 0, Feb-07 40 W Printer Power Supply Reference Design Documentation 1 © 2007 ON Semiconductor. Disclaimer: ON Semiconductor is providing this reference design documentation package “AS IS” and the recipient assumes all risk associated with the use and/or commercialization of this design package. No licenses to ON Semiconductor’s or any third party’s Intellectual Property is conveyed by the transfer of this documentation. This reference design documentation package is provided only to assist the customers in evaluation and feasibility assessment of the reference design. It is expected that users may make further refinements to meet specific performance goals 2 1 2 Overview .................................................................................................................. 4 Introduction and definitions as per Energy Star ....................................................... 5 2.1 Printer................................................................................................................ 5 2.2 Multifunction Devices (MFD) ............................................................................. 5 3 Printer Power Supply Requirements ........................................................................ 5 3.1 Efficiency requirements ..................................................................................... 5 3.1.1 Earning the ENERGY STAR ..................................................................... 6 3.1.2 Energy Star requirements.......................................................................... 6 3.2 Safety requirements .......................................................................................... 7 3.2.1 Limited Power Source ............................................................................... 7 3.2.2 Safety standards........................................................................................ 9 4 Limitations of existing solutions................................................................................ 9 5 Overcoming limitations with NCP1351 ..................................................................... 9 6 Specifications ......................................................................................................... 10 7 Reference Design Performance Summary............................................................. 11 7.1 Efficiency ......................................................................................................... 11 7.2 No-load Input Power........................................................................................ 11 8 Schematic .............................................................................................................. 12 9 Board Layout .......................................................................................................... 13 10 Bill of Material......................................................................................................... 14 11 Appendix ................................................................................................................ 16 11.1 NCP1351......................................................................................................... 16 11.2 References ...................................................................................................... 16 3 1 Overview This reference document describes a built-and-tested, GreenPointTM solution for a printer power supply. The reference design circuit consists of one single-sided 125 mm x 60 mm printed circuit board designed to fit into a printer adapter. Height is 30 mm. An overview of the entire circuit is provided by Figure 1Error! Reference source not found.. As shown in that figure, ON Semiconductor devices are available for every block of the Printer power supply; and by judicious choice of design tradeoffs, optimum performance is achieved at minimum cost. Figure 1 4 2 Introduction and definitions as per Energy Star Imaging equipments are part of our every day life. They include Copiers, Digital Duplicators, Facsimile Machines, Mailing Machines, Multifunction Devices (MFD), Printers, and Scanners. We use them everywhere for personal and professional purposes: from the big copierprinter-scanner in the office to the desktop printer we have at home and that we enjoy for giving us the possibility to quickly get the pictures of our last vacation or family event. But let’s first define the topic of this 40 W power supply GreenPointTM reference design: Desktop Printers. 2.1 Printer A commercially-available imaging product that serves as a hard copy output device, and is capable of receiving information from single-user or networked computers, or other input devices (e.g., digital cameras). The unit must be capable of being powered from a wall outlet or from a data or network connection. This definition is intended to cover products that are marketed as printers, including printers that can be upgraded into Multifunction Devices in the field. 2.2 Multifunction Devices (MFD) A commercially-available imaging product, which is a physically-integrated device or a combination of functionally-integrated components, that performs two or more of the core functions of copying, printing, scanning, or faxing. The copy functionality as addressed in this definition is considered to be distinct from single sheet convenience copying offered by fax machines. The unit must be capable of being powered from a wall outlet or from a data or network connection. This definition is intended to cover products that are marketed as MFDs or multifunction products (MFPs) 3 Printer Power Supply Requirements Along with the global warming becoming a daily issue and the price of oil increasing sharply, the entire world became aware that the current usage rate of energy is not sustainable. A few initiatives have been taken around the world and in different domains (e.g.: external power supplies, home appliances, home electronics, etc..) Naturally and because printers are widely used and consume a lot of power, they also became a field that governmental agencies wanted to address and make more energy efficient. Even if these requirements are not yet standards, most of the manufacturers have already applied these rules in their designs. 3.1 Efficiency requirements Region / Country Program name Japan Eco Mark Korea Norway, Denmark, Iceland, Finland, Sweden Energy Saving Nordic Swan Requirements for Printers 15 W / 30 W / 45 W * "Off" mode 1 W 10 W - 75 W* Laser Printer: 10 W - 85 W Ink Jet/Matrix: 6 W / "Off" 3 W 5 Demoboard compliance Yes Yes Yes Germany Blue Angel Europe GEEA Energy Star Imaging equipment 1 Watt Executive Order Energy Star Imaging equipment Europe US US 15 W / 30 W / 45 W * "Off" mode 1 W 3 W - 15 W* / "Off" mode 1 W Yes Yes Web site Yes 1W Yes Web site Yes Note: Refer to each program specifications to get the latest standby requirements. • Depends on print rate. 3.1.1 Earning the ENERGY STAR The very well know Energy Star organization has been very active and has been working on Imaging Equipment Specifications “ENERGY STAR qualified printers automatically enter a low-power “sleep” mode after a period of inactivity. Separate specifications are available for stand-alone printer models depending on paper handling size and color capabilities. Spending a large portion of time in low-power mode not only saves energy but helps printing equipment run cooler and last longer. Many ENERGY STAR qualified machines can print double-sided pages, reducing paper costs by as much as $30 a year. Businesses that use ENERGY STAR enabled office equipment may realize additional savings on air conditioning and maintenance. Over its lifetime, ENERGY STAR qualified equipment in a single home office (e.g., computer, monitor, printer, and fax) can save enough electricity to light an entire home for more than 4 years. Remember, saving energy prevents pollution. Printers are generally turned on 24 hours a day, so power management features are important for saving energy and are an easy way to reduce air pollution.” (Extract from Energy Star WEB site) 3.1.2 Energy Star requirements The Version 1.0 specification shall commence on April 1, 2007, with the exception of digital duplicators. All products, including models originally qualified under previous imaging equipment specifications, with a date of manufacture on or after the effective date, must meet the new Version 1.0 requirements in order to qualify for ENERGY STAR (including additional manufacturing runs of models originally qualified under previous specifications). The date of manufacture is specific to each unit and is the date (e.g., month and year) on which a unit is considered to be completely assembled. • Tier I – Tier I shall commence on April 1, 2007. Tier I applies to all products described in Section 2 of the specification. • Tier II – Tier II shall commence on April 1, 2009. Tier II will apply to the maximum Typical Electricity Consumption (TEC) levels for all TEC products, as well as to Standby levels for Large-format Operational Mode (OM) products and mailing machines. In addition, the definitions, products addressed, the manner in which they are addressed, and levels included for all products under this Version 1.0 specification may be reconsidered. EPA will inform stakeholders of plans to make 6 • such changes at most six months following the effective date of Tier I. March 31, 2007. Typical Electricity Consumption (TEC) Approach – A method of testing and comparing the energy performance of imaging equipment products, which focuses on the typical electricity consumed by a product while in normal operation during a representative period of time. The key criteria of the TEC approach for imaging equipment is a value for typical weekly electricity consumption, measured in kilowatt-hours (kWh). Detailed information can be found in the “ENERGY STAR Qualified Imaging Equipment Typical Electricity Consumption Test Procedure” TEC 1 Table Product(s): Copiers, Digital Duplicators, Fax Machines, Printers Size Format(s): Standard-size Marking Technologies: DT, Mono DS, Mono EP, Mono Stencil, Mono TT Tier I Tier II Product Speed (ipm) Maximum TEC (kWh/week) Maximum TEC (kWh/week) ≤ 12 1.5 kWh TBD 12 < ipm ≤ 50 (0.20 kWh/ipm)x – 1 kWh TBD > 50 ipm 0.80 kWh/ipm)x – 31 kWh TBD TEC 2 Table Product(s): Copiers, Digital Duplicators, Fax Machines, Printers Size Format(s): Standard-size Marking Technologies: Color DS, Color Stencil, Color TT, Color EP, SI Tier I Tier II Product Speed (ipm) Maximum TEC (kWh/week) Maximum TEC (kWh/week) ≤ 50 (0.20 kWh/ipm)x – 2 kWh TBD > 50 0.80 kWh/ipm)x – 28 kWh TBD Product Type & Size Format All Small Format and Standard-size OM Products without Fax Capability All Small Format and Standard-size OM Products with Fax Capability All Large Format OM Products and Mailing Machines Standby (W) – Tier 1 Standby (W) – Tier 2 1 Tier 1 levels remain unchanged 2 Tier 1 levels remain unchanged N/A TBD 3.2 Safety requirements 3.2.1 Limited Power Source A printer power supply must be compliant with the limited power source requirement as defined in section. 2.5 of IEC 60950-1 1st Edition and for each output independently. A Limited Power Source must include an isolating transformer and must comply with one of the following: • The output is inherently limited in compliance with Table 1 or 7 • • • • An impedance limits the output in compliance with Table 1. iF a PTC is used, it must pass the test specified in IEC 60730-1, clause 15, 17, J15 and J17 or An over current protective device is used and the output is limited in compliance with Table 2, or A regulation network limits the output in compliance with Table 1 both under normal and after single fault, or A regulation network limits the output in compliance with Table 1 and an over current protective device limits the output in compliance with Table 2 after single fault Where an over current protective device is used, it must be a fuse, or a non adjustable, non auto-reset, electromechanical device. Output voltage (Uoc) Output current (Isc) Apparent power (S) A VA Va.c Vd,c ≤ 20 ≤ 20 ≤8 ≤ 8 * Uoc 20 < Uoc ≤ 30 20 < Uoc ≤ 30 ≤8 ≤ 100 20 < Uoc ≤ 60 ≤ 150 / Uoc ≤ 100 • Uoc : Output voltage measured with all load disconnected. Voltages are fir substantially sinusoidal a.c. and ripple fee sinusoidal a.c. and d.c with ripple greater than 10%. The peak voltage shall not exceed 42.4 V. • Isc: Maximum output current with any non capacitive load, including a short circuit, measured 60 s after the application of the load • Maximum output VA with any load, initial transients lasting less than 100 ms are permitted to exceed the limit Table 1: limits for inherently Limited Power Sources Current rating of protective device (S) Va.c Vd,c VA ≤ 20 ≤ 20 ≤5 ≤ 1000 / Uoc ≤ 250 20 < Uoc ≤ 30 20 < Uoc ≤ 30 ≤ 100 / Uoc 20 < Uoc ≤ 60 ≤ 100 / Uoc • Uoc : Output voltage measured with all load disconnected. Voltages are fir substantially sinusoidal a.c. and ripple fee sinusoidal a.c. and d.c with ripple greater than 10%. The peak voltage shall not exceed 42.4 V. • Isc: Maximum output current with any non capacitive load, including a short circuit, measured 60 s after the application of the load. Current limiting impedance in the equipment remains in the circuit during the measurement but over current protective devices are bypassed • Maximum output VA with any load. Current limiting impedance in the equipment remains in the circuit during the measurement but over current protective devices are bypassed. Initial transients lasting less than 100 ms are permitted to exceed the limit. The reason for making the measurements with over current limiting devices bypassed is to determine the amount of energy that is available to cause possible overheating during the operating tome of the protective devices • The current rating of over current protective devices are based on fuses and circuit breakers that beak the circuit between 120 s with a current equal to 210% of the current rating specified in that table Output voltage (Uoc) Output current (Isc) A Apparent power (S) VA Table 2: limits for Power Sources non-inherently limited (over current protective device required) 8 3.2.2 Safety standards • • • • Underwriters Laboratories Recognized Component power supply assembly for use in Information Technology Equipment per the following standard: UL1950, third edition dated March 1,1998 without deviations. Canadian Standards Association Certified Component per the following standard: CAN/CSA C22.2 No. 950-1-03. NEMKO licensed to EN60950-1: 1st edition (Safety of Information Technology Equipment Including Electrical Business Equipment), plus EMKO-TSE (74-SEC) 203/94, (Nordic deviations). IEC 60950-1 1st Edition 4 Limitations of existing solutions The existing adapters barely meet the current requirements for efficiency in light load conditions and standby power in no-load; whereas more stringent requirements are coming. In addition the total cost of the adapter must be extremely low, as this is a highly competitive market. Therefore meeting these requirements while ensuring reliability and reproducibility of the adapter performances is a challenge. 5 Overcoming limitations with NCP1351 This design using NCP1351C offers a perfect solution for printer adapter applications. Thanks to the fixed peak current / variable off time architecture, this adapter has high efficiency from nominal to light loads (including the various printer sleep modes); as well as a very low no-load consumption. It also features the ability to transiently deliver peak power while providing effective protection functions such as latched over-load, shortcircuit and over-voltage protections. In addition the unique NCP1351C architecture allows reducing the high-voltage input capacitor by one third compared to the state-ofthe-art printer adapters, thus saving cost and size for the same performances. Implementing a fixed peak current mode control (also known as “quasi−fixed” ton), the NCP1351 modulates the off time duration according to the output power demand. In high power conditions, the switching frequency increases until a maximum is hit. This upper limit depends on an external capacitor selected by the designer. In light load conditions, the off time expands and the NCP1351 operates at a lower frequency. As the frequency reduces, the contribution of all frequency−dependent losses accordingly goes down (driver current, drain capacitive losses, switching losses), naturally improving the efficiency at various load levels. • Peak current compression at light loads: reducing the frequency will certainly force the converter to operate into the audible region. To prevent the transformer mechanical resonance, the NCP1351 gradually reduces – compresses – the peak current setpoint as the load becomes lighter. When the current reaches 30% of the nominal value, the compression stops and the off duration keeps expanding towards low frequencies. • Low standby power: the frequency reduction technique offers an excellent solution for designers looking for low standby power converters. Also, compared to the skip−cycle method, the smooth off time expansion does not bring additional ripple in no−load conditions: the output voltage remains quiet. • Natural frequency dithering: the quasi−fixed ton mode of operation improves the EMI signature since the switching frequency varies with the natural bulk ripple voltage. 9 • • • Extremely low start−up current: built on a proprietary circuitry, the NCP1351 startup section does not consume more than 10 µA during the startup sequence. The designer can thus easily combine startup time and standby consumption. Overload protection based on Fault Timer: every designer knows the pain of building converters where a precise over current limit must be obtained. When the fault detection relies on the auxiliary VCC, the pain even increases. Here, the NCP1351C observes the lack of feedback current to start a timer to countdown. At the end of its charge, the timer permanently latches the controller off. What is unique with the NCP1351C is that the Fault timer does not start when the controller delivers its maximum power (corresponding to the maximum switching frequency), but at 60% of this maximum: it means that when the timer is counting the power supply can transiently deliver a higher power. This is particularly suitable in printer adapter applications where the power supply must be able to deliver transient power peaks while meeting the Limited Power Source (LPS) requirements. Latch Fault Input: a dedicated input lets the designer externally trigger the latch to build additional protections such as overvoltage (OVP) or overtemperature (OTP). 6 Specifications Input Voltage: Universal input 85 Vac to 265 Vac, 47-63 Hz Power Supply Output voltages: • 32 V / 1 A • 16 V / 0.625 A Peak Power: • 80 W (32 V / 2.5 A and 16 V / 0 A ) during 40 ms • 62 W (32 V / 1.94 A and 16 V / 0 A) during 400 ms Efficiency requirements: • > 80 % at full load (40 W) • > 70 % in sleep modes (2 W and 4 W) • Pin < 0.3 W in no-load conditions Protections: • Latched overpower protection below 100 W (to meet LPS) • Latched overvoltage protection (OVP) • Latch recovery time < 3 s Others: • Start-up time < 3 s • No damage and no output voltage bouncing during brown-in and brown-out tests 10 7 Reference Design Performance Summary 7.1 Efficiency Efficiency (%) 100 90 80 120 Vac 70 230 Vac 60 50 40 30 20 10 Pout (W) 0 0 5 10 15 20 7.2 No-load Input Power Ac Input Voltage Input power consumption 120 V 73 mW 230 V 137 mW 11 25 30 35 40 8 Schematic D13 D5 U1 L3 C18 C13 C12 R5 C20 C19 32V GND 16V R15 L2 R24 D4 C15 L1 X6 R6 C17 C16 R20 D7 D3 R23 R10 R2 C14 1 R13 Aux D9 NCP1351C X4x Fuse R31 R28 D10 R18 8 2 7 3 6 4 5 D11 R21 R19 R1 X11 C21 X4 R14 C6 C1 R8 C4 C3 C10 12 C8 R11 C7 X10 R30 C23 R22 9 Board Layout 13 10 Bill of Material Designator Qty Description Value Tol. Footprint 5 % SMD 1206 C1, C4, C15, C18, C21 C3 C5 C6 C7 C8 C9 C10 C12 C13 C14 C16 C17 C19 C20 C23 C101 5 SMD capacitor 100 nF / 50 V 1 0 1 1 1 0 1 1 1 1 1 1 1 1 1 0 electrolytic capacitor SMD capacitor SMD capacitor electrolytic capacitor SMD capacitor SMD capacitor SMD capacitor Film capacitor electrolytic capacitor x2 capacitor electrolytic capacitor electrolytic capacitor electrolytic capacitor electrolytic capacitor y1 capacitor SMD capacitor 4.7 µF / 50 V 180 pF / 50 V 47 µF / 50 V 10 nF / 50 V 1.5 µF 10 nF / 630V 100 µF / 400 V 330 nF / 250 Vac 1000 µF / 50 V 100 µF / 50 V 1000 µF / 25 V 100 µF / 25 V 2.2 nF / 250 Vac - D1 D2 1 0 0 Ω / 0.25 W - D3 1 D4 1 D5, D7 2 D9 D10 D11 D12 D13 D14 1 1 1 1 1 0 SMD resistor Zener diode High-voltage switching diode BAS20 Fast-recovery rectifier 1N4937 Schottky rectifier MBR20100CT Zener diode Zener diode Switching diode Zener diode Standard rectifier Switching diode HS1 HS2, HS3 1 2 U1 1 U2 1 X4 1 X6 1 Heatsink TO-220 heatsink Rectifier bridge DB105 CMOS IC NCP1351A Optocoupler SFH615 Common-mode choke 14 20 % 5% 5% 20 % 5% 5% 10 % 20 % 20 % 20 % 20 % 20 % 20 % 20 % 5% radial SMD 1206 SMD 1206 radial SMD 1206 SMD 1206 SMD 1206 radial radial radial radial radial radial radial radial SMD 1206 5 % SMD 1206 5 % SOD-123 200 mA / 200 V - SOT-23 1 A / 600 V - axial 20 A / 100 V - TO-220 17 V / 0.5 W 60 V / 0.5 W 200 mA / 75 V 6.2 V / 0.5 W 1 A / 1000 V - 5% 5% 5% - SOD-123 SOD-123 SOD-123 SOD-123 axial SOD-123 6.2 ºC / W 27 ºC / W - radial - 1A / 600 V - DIP-4 - - SOIC-8 - - DIP-4 2 * 15 mH/ 1 A - radial X10 1 X11 Q1 1 0 T1 1 J1 1 F1 1 Panasonic ELF-25F108A shunt regulator TL431 Power MOSFET N-Channel PNP transistor Transformer Coilcraft GA0007-AL connector 2.5 – 36 V 5% TO-92 3 A / 600 V - - TO-220 TO-92 - - radial Fuse 2 A / 250 Vac L1 1 L2, L3 1 SMD inductor Coilcraft inductor R1 R2 R5, R6 R7 R8, R19 R9, R12 R10, R11, R18 R13 R14 R15 R16 R17 R20 R21 R22 R23, R24 R25 R26 R28 R30 R31 RV1 1 1 2 1 2 2 3 1 1 1 0 0 1 1 1 2 0 1 1 1 1 1 SMD resistor resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor SMD resistor NTC 15 230 Vac radial T radial 4.7 µH / 10 A - SMD DO1605T radial 15 Ω / 0.25 W 4.7 MΩ / 0.33 W 330 kΩ / 0.25 W 0 Ω / 0.25 W 2.7 kΩ / 0.25 W 0 Ω / 0.25 W 1 kΩ / 0.25 W 3.4kΩ / 0.25 W 0.33 W / 0.5 W 150 kΩ / 2 W 100 kΩ / 0.25 W 56 kΩ / 0.25 W 10 kΩ / 0.25 W 3.3 MΩ / 0.25 W 0 Ω / 0.25 W 8.2 kΩ / 0.25 W 47 kΩ / 0.25 W 180 kΩ / 0.25 W - 5% 5% 1% 5% 5% 5% 5% 1% 1% 5% 1% 1% 1% 5% 1% 1% 1% 1% 1% - SMD 1206 axial SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 2010 axial SMD 2010 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 Radial 10 µH 11 Appendix 11.1 NCP1351 • • • Datasheet AND8263: Evaluation Board, 19 V - 3 A Adapter AND8278: Evaluation Board, 16 V/ 32 V 40 W Printer Power Supply 11.2 References CSC (China): • http://www.cecp.org.cn/englishhtml/index.asp Eco Mark (japan) • http://www.ecomark.jp/english/ http://www.ecomark.jp/english/nintei.html • GEEA (Europe): • http://www.efficient-appliances.org/ • http://www.efficient-appliances.org/Criteria.htm Energy Star: http://www.energystar.gov/ • • http://www.energystar.gov/index.cfm?c=product_specs.pt_product_specs • http://www.energystar.gov/index.cfm?c=archives.img_equip_spec&layout=print • http://www.energystar.gov/index.cfm?fuseaction=find_a_product.ShowProductGroup&pgw_code=P R 1 Watt Executive Order: http://oahu.lbl.gov/ • • http://oahu.lbl.gov/level_summary.html 16