18 Feb 2011 Data Sheet No. PD97152 IRAC1152-350W Reference Design Kit for IR1152 (Fixed 66kHz Frequency, One Cycle Control PFC IC with Brown-Out Protection) Product Summary REFERENCE DESIGN KIT FEATURES * * * * * * * * * * IEC61000-3-2 Class D Standards Compliant Less than 10% Total Harmonic Distortion (115230VAC/350W) Universal AC Input Voltage capability Fully regulated 388V DC bus Full load start-up, no minimum load requirements Current loop controlled soft-current limit protection for overpower limitation at minimum VAC High Efficiency Si Superjunction MOSFET boost switch Hyper-fast recovery Si boost diode On-board Flyback SMPS for 15V VCC supply (option to disable for external VCC bias supply) Single layer PCB illustrating layout best-practices AC Input Voltage 85-264VAC AC Input Line Frequency 47-63Hz DC Bus Output Voltage 388V +/- 2% Maximum output power 350W Minimum Load Requirement None Power Factor (115-230VAC/350W) Total Harmonic Distortion (115-230VAC/350W) <10% Start-up time 60ms >0.98 IR1152 PFC IC FEATURES * * * * * * * * * * * * * * PFC IC with IR proprietary "One Cycle Control" Continuous conduction mode boost type PFC Fixed 66kHz switching frequency Average current mode control Input line sensed brownout protection DC bus overvoltage protection (Dual & Dedicated) DC bus open feedback loop protection Cycle-by-cycle peak current limit (DC bus voltage foldback type) Soft-current limit protection VCC under voltage lockout Programmable soft-start Micropower startup & sleep mode (user-initiated) 750mA peak gate drive Optimized pin-out for single layer PCB layout Introduction IRAC1152-350W is a full function AC-DC reference design showcasing the operation of IR1152 PFC IC in a continuous conduction mode boost converter for achieving power factor correction, sub-10% harmonic current distortion and EN61000-3-2 Class D harmonic current limits standard compliance. Designed to be operated from 85-264VAC universal input voltage, IRAC1152-350W delivers 350W continuous output power via a fully regulated 388V DC bus. Thanks to IR1152 PFC IC, the reference design is rendered with a very high level of safety against system abnormalities such as AC line sag, DC bus voltage loop feedback loss, system overcurrent & overvoltage. Combining the cost-advantage of single layer PCB and ferrite-core boost inductors with optimized PCB layout, the IRAC1152-350W reference design is an excellent design example that can be seamlessly imported & integrated by system designers that require a high-performance PFC stage at the AC-DC front-end of their designs in a variety of applications. Rev 1.0 (c) 2010 International Rectifier 1 IRAC1152-350W Table of Contents Introduction .........................................................................................................................................................1 Description of Hardware & Key Operating Features ...........................................................................................4 Hardware Installation & Operating Procedure ....................................................................................................7 Performance Characterization ............................................................................................................................9 IRAC1152-350W Schematics ...........................................................................................................................19 IRAC1152-350W Bill of Materials (BoM) ..........................................................................................................22 IRAC1152-350W PCB & Component Layout ...................................................................................................24 List of Figures Figure 1 IRAC1152-350W test set-up.................................................................................................................7 Figure 2: IRAC1152-350W external Vcc connection ..........................................................................................8 Figure 3. Power factor vs. Line/Load Variation of IRAC1152-350W...................................................................9 Figure 4. Current Harmonics at 85-264VAC, 350W .........................................................................................10 Figure 5. Current Harmonics at 85-264VAC, 87.5W (25% of rated power)......................................................10 Figure 6. THD at 350W across 85-264VAC for IRAC1152-350W ....................................................................11 Figure 7. EMI filter stage causes phase-shift in Input Current Waveform (264VAC, 350W)............................13 Figure 8. Power factor vs. Line/Load for modified IRAC1152-350W with single stage EMI filter .....................13 Figure 9. 2X AC frequency ripple in DC bus capacitor at 85VAC, 350W .........................................................14 Figure 10. 2X AC frequency ripple in DC bus capacitor at 264VAC, 350W .....................................................14 www.irf.com (c) 2010 International Rectifier 2 IRAC1152-350W Safety Precautions ! ATTENTION: The ground potential of the IRAC1152-350W is biased to a negative DC bus voltage potential. In order to be able to safely measure voltage waveform by oscilloscope, the use of an isolation transformer at the AC input is recommended. Though floating the ground potential of the scope is often practiced, it is not recommended. Failure to follow these guidelines so may result in personal injury or death. ATTENTION: The IRAC1152-350W system contains dc bus capacitors & capacitors on the rectified AC line (C6, C9, C10, C21, C22), which take time to discharge after removal of main supply. Remove and lock out power from the IRAC1152-350W board before you attempt to disconnect or reconnect wires or perform service. Wait at least one minute after removing power to discharge the capacitor voltages. Do not attempt to service the reference design until all capacitor voltages have discharged to zero. Failure to do so may result in bodily injury or death. ! ! ! ATTENTION: Only personnel familiar with the IRAC1152-350W system should plan or implement the installation, start-up, and subsequent maintenance of the system. Failure to comply may result in personal injury and/or equipment damage. ATTENTION: The surface temperatures of the IRAC1152-350W board & heatsink may become hot, which may cause injury. A fan is recommended to cool the board whenever operating at the full rated power for prolonged periods. ATTENTION: The IRAC1152-350W system contains ESD (Electrostatic Discharge) sensitive parts and assemblies. Static control precautions are required when installing, testing, servicing or repairing this assembly. Component damage may result if ESD control procedures are not followed. If you are not familiar with static control procedures, reference applicable ESD protection handbook and guideline. ! ! ! ATTENTION: An incorrectly applied or installed board can result in component damage or reduction in product life. Wiring errors, supplying an incorrect AC supply, or excessive ambient temperatures may result in system malfunction. ATTENTION: IRAC1152-350W system is shipped with packing materials that need to be removed prior to installation. Failure to remove all debris and packing materials which are unnecessary for system installation may result in abnormal operating condition. www.irf.com (c) 2010 International Rectifier 3 IRAC1152-350W Description of Hardware & Key Operating Features The key features of the IRAC1152-350W hardware are listed below. The user is referred to IRAC1152-350W schematics provided later in the document for the following discussions and also to "350W PFC Converter Design Example" section in IR1152 Application Note AN-1150 where the design and component selection for IRAC1152-350W is explained in detail in. AC Input Stage (before bridge rectifier) * EMI Stage is comprised of a 2 stage EMI filter composed of 3X 0.47uF X-capacitors & 2X commonmode EMI choke coils with 10mH (16kHz) rated magnetic impedance; There are no Y-capacitors installed, but they can be installed in sockets C3 & C4 if the user so desires. * In rush current limitation is provided by a NTC (negative thermal co-efficient) resistor offering 5ohm impedance at 25C * A 250V, 6.3A fuse is included for current protection. Power Stage * Bridge Rectifier: 600V, 8A bridge rectifier (B1) is employed. * Boost Inductor: A 600uH, 6A Boost inductor (L1) based on PC40 ferrite magnetic core and EER42/42/20 core size is employed. With 600uH of boost inductance, the ripple current factor is about 0.3 (30% current ripple) near peak of AC sinusoid at 85VAC, 350W (DC bus voltage=388V). The user can substitute this with another inductor in order to adjust the ripple current factor. * Boost Switch & Gate Drive Circuit: 2X 600V, 20A superjunction MOSFETs (Q3 & Q4) connected in parallel are employed for boost switch function. The gate drive for MOSFETs is provided by a NPNPNP buffer circuit in order to render a tight gate-drive switching loop. It is noted that, since NPN-PNP buffer is a base-follower circuit, the voltage clamp on GATE output of IR1152 IC is also closely maintained on the output of the NPN-PNP buffer circuit driving the MOSFETs. The user can also disable the NPN-PNP buffer circuit & drive the MOSFETs directly using IR1152 IC's output GATE driver by implementing the following steps: i. Un-install jumper J4 ii. Uninstall surface mount resistors R18 & R19 iii. Install jumper J3 iv. Modify IR1152 GATE series resistor R16 (0 ohms in default configuration), if necessary Localized gate resistor & diode networks (R20, R22, D7 for Q3 & R5, R6, D4 for Q4) is used to preferentially adjust turn-on & turn-off dV/dt. Turn-on is slower to control reverse recovery behavior of boost diode. Finally a Schottky diode, D6 between GATE & COM pins of IR1152 is used to clamp any negative voltage spikes that can cause IC latch-up. * Boost Diode: A 600V, 8A hyper-fast recovery diode (D5) is employed as boost diode with snubber circuit (R7, C8) to limit voltage spikes. * DC Bus Capacitor: 330uF, 450V capacitor (C10) is employed on the DC bus for acceptable ripple at 350W power rating at 388VDC. A 1W, 470kohm bleed resistor (R10) is used across C10 to discharge the bus voltage. * Current Sense Resistor: R27 & R28 are sockets allocated for current sense resistor. Dual footprints are provided for both sockets for flexibility. IRAC1152-350W employs a 50mohm, 5W current sense resistor in R27 socket (R28 is not populated). The choice of current sense resistor programs the following: i. Current level at which cycle-by-cycle peak current protection limit is encountered. When this is encountered, IR1152 instantaneously pulls the GATE output low. www.irf.com (c) 2010 International Rectifier 4 IRAC1152-350W ii. Current level (and hence power level) at which soft-current protection limit is invoked at a specific VAC voltage. When this is encountered, IR1152 limits the duty cycle of the PFC switch which the causes DC bus voltage to foldback (or droop). This is how IR1152 provides overpower limitation. The power level at which this protection is encountered increases with increasing VAC. The current sense resistor employed in IRAC1152-350W is such that the reference design is guaranteed to deliver 350W at VAC=85VAC without DC bus voltage foldback. At VAC=85VAC, the DC bus voltage foldback occurs at about 430W output power in IRAC1152-350W. IRAC1152-350W Default Set-point Cycle-by-Cycle Peak Current Protection Limit Soft-current Protection Limit at 85VAC Typical Level 15A 9.8A CAUTION: If the user attempts to modify the power level of the PCB by changing the current sense resistor, attention must be paid to the component ratings - semiconductors (bridge rectifier, boost switch, boost diode), boost inductor, fuse, DC bus capacitor - and system thermal performance (use a fan to cool heatsink, run at lower ambient temperature etc). * Current Monitoring: Jumper J7 is provided for monitoring the inductor current and Jumper J8 is provided for monitoring the PFC switch current. Current loops (for use with a magnetic current probe) can be established by uninstalling the onboard jumper wires and installing a current loop of adequate length to fit the probe. On-board Flyback SMPS * An onboard DC-DC Flyback SMPS delivers 16VDC for biasing the VCC pin of IR1152 IC. The Fyback is configured to supply 16VDC when the VAC voltage is around 35-40VAC. If user desires to provide IR1152 VCC bias using an external DC supply in order to study the standby & start-up current requirements of IR1152, then onboard Flyback SMPS can be disconnected by implementing the following steps: i. Un-install jumper J13 ii. Though not necessary, un-installing diode D8 is also recommended for safety reasons to fully disable the Flyback power supply iii. Input connector J15 can be used for providing external DC supply to bias the VCC pin of IR1152; please pay attention to the connector biasing as shown in Figure 2. in the Installation and Operating Instructions section of this document IR1152 IC Control Circuit * VFB Pin - The DC bus voltage is programmed using the resistor divider comprised of R8, R23 & R24. By adjusting R24, the user can modify the DC bus voltage. Increasing R24 will decrease DC bus voltage. Decreasing R24 will increase DC bus voltage. By default, the overvoltage comparator on VFB pin programs the overvoltage protection set-point of IRAC1152-350W to 106% of DC Bus voltage and overvoltage protection reset set-point of IRAC1152-350W to 103% of DC Bus voltage. IRAC1152-350W Default Set-point DC Bus Regulation Voltage Overvoltage Protection Set-point (VFB pin) Overvoltage Protection Reset Set-point (VFB pin) * Typical Level 388V 411V 402V OVP Pin - OVP pin resistor divider (R9, R25 & R26) uses the same component values as VFB pin resistor divider. This programs the overvoltage protection set-point of comparator on OVP pin to be same as that of VFB pin. This is the recommended configuration & default for IRAC1152-350W. Thus, the function of OVP pin is two-fold: i. dedicated pin to monitor DC bus voltage for overvoltage situations ii. along with overvoltage comparator on VFB pin, the OVP pin provides dual overvoltage protection i.e. additional redundancy in system overvoltage protection in order to guarantee a very high level of safety www.irf.com (c) 2010 International Rectifier 5 IRAC1152-350W IRAC1152-350W Default Set-point Overvoltage Protection Set-point (OVP pin) Overvoltage Protection Reset Set-point (OVP pin) Typical Level 411V 402V CAUTION: The following cautionary statements apply if user attempts to modify value of R24 or R26 in IRAC1152-350W. o If the modification causes R26<R24, then overvoltage protection set-point & overvoltage protection reset set-point of OVP pin will be higher than that of VFB pin. This configuration is acceptable. However, it is noted that the overvoltage protection set-point & overvoltage protection reset set-point of IRAC1152-350W reference design as a whole is still determined by the set-points of VFB pin. o If the modification causes R26>R24, then overvoltage protection set-point & overvoltage protection reset set-point of OVP pin will be lower than that of VFB pin. This configuration is generally NOT recommended because the modification may render overvoltage protection reset set-point of OVP pin to be less than DC bus voltage. This may cause DC bus voltage regulation issues & undesirable oscillations during system start-up & load transients. * BOP Pin - Resistors R3, R4 & R12 and capacitor C14 constitute a divide-and-average circuit on the BOP pin. The choice of resistor divider components (R3, R4 & R12) determines VAC voltage at which IC exits Brown-out fault condition during system start-up. Decreasing R12 will cause IC to exit Brown-out fault condition at a higher VAC during start-up (and vice versa). The capacitor C14, which implements the averaging function, also programs amplitude of 2X AC frequency ripple voltage on BOP pin. As VAC is decreased, when the valley of VBOP ripple voltage encounters Brown-out protection threshold then a Brown-out fault condition is immediately triggered. Thus it is VBOP ripple voltage which determines at what VAC voltage a Brown-out fault condition is triggered during AC line sag. And by controlling VBOP ripple, the value of C14 determines VAC voltage at which Brown-out fault condition is triggered. If C14 is increased, VBOP ripple is reduced and Brown-out fault is triggered at a lower VAC (and vice versa). Diode D2 in BOP circuit is optional. IRAC1152-350W Default Set-point Brown-out Protection Trigger Threshold during AC line sag (350W) Brown-out Protection Enable Threshold during system start-up (0W) Typical Level 55VAC 65VAC * VCOMP Pin - C12, C13 & R15 are involved in the following functions: o voltage loop compensation (location of pole & zero in voltage loop feedback response & phase margin) o C12 primarily determines the system soft-start time during start-up The user is recommended to review "Voltage Loop Compensation" section in AN-1150 before modifying any of these components, since such an explanation is outside the scope of this document. * ISNS Pin -The VISNS signal from the current sense resistor is filtered using RC network created by R11 & C11 in order to provide a clean signal to the IR1152 IC. * VCC Pin - A 22uF Tantalum surface-mount capacitor and a 1uF ceramic surface mount capacitor (located as close as possible to VCC & COM pins) are used to provide optimum decoupling for the VCC bias to IR1152 IC. An 18V zener diode, D3 is used to clamp overvoltage spikes on VCC pin & protect IR1152 IC. * COM Pin - A STAR connection point located very close to the COM pin of the IC is used to individually terminate all the control signal return loops (VCC, VCOMP, VFB, OVP, BOP & power GND). Please refer to PCB Layout Features section of this document for more information. * GATE Pin - Please refer to Boost Switch & Gate Drive Circuit section of this document for more information. www.irf.com (c) 2010 International Rectifier 6 IRAC1152-350W PCB Layout Best Practices & Noise Suppression Features in IRAC1152-350W IRAC1152-350W is based on a single layer PCB & jumper connections for cost-reduction purpose. The PCB layout in IRAC1152-350W, especially control circuitry, is an excellent example that can be studied & reproduced by the user in his designs in order to achieve clean, noise-free operation in end application. The following points are noteworthy: * VCOMP-COM voltage loop:- The VCOMP voltage is the most important control voltage for IR1152 operation. The trace connection from C12 & C13 components in VCOMP-COM control loop to COM pin must be done in an independent & isolated manner (i.e. it must be a dedicated trace and not share the ground return loop of any other control circuit such as VFB-COM, VCC-COM etc). This is very important to achieve a clean VCOMP signal * COM STAR connection & Dedicated ground return loops:- A STAR connection point located very close to the COM pin of the IC is used to individually terminate all the control signal ground return loops (VCC-COM, VCOMP-COM, VFB-COM+OVP-COM, BOP-COM & VISNS-COM i.e. power GND & ground plane). Each control loop has its own dedicated ground trace which is not shared with ground return of other loops. This STAR connection ensures that the noise in one control signal loop does not proliferate into another control loop. * IR1152 pin-out & ground plane in single layer PCB:- The pin-out arrangement in IR1152 is optimized for single layer PCB layout to facilitate a ground plane beneath the IC for shielding noise. VCOMP & COM pins are next to each other for a tight loop. VFB & OVP are located next to each other since both communicate to DC bus via resistor dividers. VCC & COM are located close to each other to facilitate placement of 1uF decoupling capacitor in very close proximity to the IC. Careful routing of the control loops & use of jumper wires to achieve STAR connection also enables a ground plane beneath IR1152 in IRAC1152-350W. Note that the ground plane does not function as a current carrying trace to COM pin since it is not a part of any loop i.e. the only connection to the ground plane is the COM pin to establish ground bias. * ISNS voltage filtering:- Notice that R11 & C11, which are used for RC filtering the ISNS signal, are located close to the current sense resistor. This serves to filter the ISNS signal noise near the noise source (i.e. current sense resistor) rather than near the IC. Also, notice that the noise filter RC circuit is a dedicated loop by itself in order to prevent noise proliferation. Hardware Installation & Operating Procedure The recommended test set-up for IRAC1152-350W is shown in Figure 1. Power Analyzer (V out) Vin Vin Vout Vout DMM V AC1 AC Prog Source or Variac (0 - 265Vac) AC2 (J1) ACIN1 (J6) + ACIN2 - + E-Load - Figure 1 IRAC1152-350W test set-up www.irf.com (c) 2010 International Rectifier 7 IRAC1152-350W Load Connection Connect high voltage resistive or electronic load, capable of 350W continuous power to connector J6 as shown in Figure 1. Pay attention to the polarity of the terminals in the connector. There is no minimum load requirement for operating IRAC1152-350W. The DC bus voltage is monitored at test-points VOUT and RTN. Always monitor the DC bus voltage to ensure that the capacitor voltage is discharged completely prior to adding or removing load connections from the demo board. AC Input Connection Connect a 60Hz AC power source, capable of operation up to 264VAC to connector J1 as shown in Figure 1. The AC input voltage can be monitored at test points AC-IN1 and AC-IN2. Once power is applied to demo board, potentially lethal high voltages will be present on board and necessary precautions should be taken to avoid serious injury. The use of an isolation transformer on the AC side is highly recommended, so that all the control signals on the test points can easily be probed by using regular oscilloscope probes. Though floating the ground potential of the scope is often practiced, it is not recommended. Failure to follow these guidelines so may result in personal injury or death. ATTENTION: The IRAC1152-350W system contains dc bus capacitors & capacitors on the rectified AC line (C6, C9, C10, C21, C22), which take time to discharge after removal of main supply. There is a 470k (R10) bleed resistor on the DC bus capacitor, whose voltage is monitored at test points VOUT and RTN. There is a 12kohm (R29) bleed resistor on the output of the Flyback power supply, whose voltage is monitored at test points VCC and COM. However, there is no bleed resistor across capacitor C22 located in the Flyback power supply and C6 locating in the main PFC circuit, both of which sustain the rectified AC voltage. Remove and lock out power from the IRAC1152-350W board before you attempt to disconnect or reconnect wires or perform service. Wait at least one minute after removing power to discharge the capacitor voltages. Do not attempt to service the reference design until all capacitor voltages have discharged to zero. Failure to do so may result in bodily injury or death. ! VCC Supply Connection (if necessary) If user desires to provide IR1152 VCC bias using an external DC supply in order to study the standby & startup current requirements of IR1152, then onboard Flyback SMPS can be disconnected by implementing the following steps: i. Un-install jumper J13 ii. Though not necessary, un-installing diode D8 is also recommended for safety reasons to fully disable the Flyback power supply from the iii. Input connector J15 can be used for providing external DC supply to bias the VCC pin of IR1152; Pay attention to the polarity of the terminals in the connector as shown in Figure 2. OPTIONAL EXTERNAL VCC SUPPLY Connect 15VDC - + Disconnect Disconnect Figure 2: IRAC1152-350W external Vcc connection www.irf.com (c) 2010 International Rectifier 8 IRAC1152-350W Power-up Once all the connections are made the system can be powered up. There is no minimum load requirement during power-up and the system can be powered-up at any load from 0W to 350W. If the AC line is increased gradually: * the onboard Flyback power supply will establish the VCC bias supply of 16VDC at around 35-40VAC * the PFC converter will start boosting as soon as the IC exits the Brown-out fault condition during start-up - around an AC voltage of 65-70VAC at 0W load and at an AC voltage of 70-75VAC under the presence of any load. If an external DC power supply is used for the VCC bias, then there is no strict biasing sequence for VAC and DC supply. It is OK to supply either voltage first. Performance Characterization DC Bus Voltage Regulation DC bus voltage variation is less than 0.2% across line (85-264VAC) & load (0-350W). There is absolutely no minimum load requirement to maintain voltage regulation. 85VAC 115VAC 180VAC 230VAC 264VAC 350W 389.10 389.15 389.18 389.21 389.21 262.5W 389.13 389.17 389.22 389.24 389.26 175W 389.15 389.19 389.24 389.26 389.29 87.5W 389.19 389.20 389.26 389.31 389.37 35W 389.24 389.26 389.34 389.45 389.54 0W 389.51 389.59 389.68 389.69 389.69 DC Bus voltage (in V) variation in IRAC1152-350W Power Factor IRAC1152-350W delivers power factor greater than 0.98 at 350W, 115-230VAC. At light load condition, there is some drop in power factor which is primarily due to X-capacitors in EMI filter. By reducing the X-capacitors in the EM filter stage, the light load performance can be improved. This is demonstrated later in this document. 1.05 1.00 Power Factor 0.95 0.90 85VAC 0.85 115VAC 230VAC 0.80 264VAC 0.75 0.70 0.65 0 50 100 150 200 250 300 350 400 Output Power (W) Figure 3. Power factor vs. Line/Load Variation of IRAC1152-350W www.irf.com (c) 2010 International Rectifier 9 IRAC1152-350W Input Current Harmonics 10 Harmonic Current Amplitude (A) 85VAC Input, 350W Output 264VAC Input, 350W Output 1 Class D Limits (350W) 0.1 0.01 0.001 0.0001 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Harmonic Order (#) Figure 4. Current Harmonics at 85-264VAC, 350W Harmonic Current Amplitude (A) 10 1 85VAC Input, 87.5W Output 264VAC Input, 87.5W Output 0.1 Class D Limits (87.5W) 0.01 0.001 0.0001 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Harmonic Order (#) Figure 5. Current Harmonics at 85-264VAC, 87.5W (25% of rated power) www.irf.com (c) 2010 International Rectifier 10 IRAC1152-350W Total Harmonic Distortion IRAC1152-350W delivers less than 10% of Total Harmonic Distortion at the rated 350W output power. 9 Total Harmonic Distortion (%) 8 7 6 5 4 3 2 0 50 100 150 200 250 300 AC Input Voltage (VAC) Figure 6. THD at 350W across 85-264VAC for IRAC1152-350W www.irf.com (c) 2010 International Rectifier 11 IRAC1152-350W Steady-state Input Current Waveforms (Ch 2: Input Voltage, Ch1: Input Current) 85VAC, 350W 115VAC, 350W 230VAC, 350W 264VAC, 350W www.irf.com (c) 2010 International Rectifier 12 IRAC1152-350W Effect of EMI Filter stage (X-capacitors) on Input Current The X-capacitors (C1, C2 & C5) in EMI filter causes a phase shift in input current with respect to the input AC voltage and "current steps" at VAC zero-crossings. This is more obvious at lower current amplitudes (such as at 264VAC, 350W condition). Notice however that the inductor current being regulated by the IC maintains very good symmetry with respect to the AC input voltage indicating that power factor correction stage is operating normally. Figure 7. EMI filter stage causes phase-shift in Input Current Waveform (264VAC, 350W) As mentioned earlier, the X-capacitors in the EMI stage contribute to drop in power factor at light load conditions. By reducing to a single stage EMI filter (remove C1, C2 & L1), the power factor at light load can be greatly improved. This is depicted in Figure 8 below. 1.05 1.00 Power Factor 0.95 0.90 0.85 85VAC 0.80 115VAC 230VAC 0.75 264VAC 0.70 0.65 0 50 100 150 200 250 300 350 400 Output Power (W) Figure 8. Power factor vs. Line/Load for modified IRAC1152-350W with single stage EMI filter www.irf.com (c) 2010 International Rectifier 13 IRAC1152-350W DC Bus Capacitor Ripple Voltage The sizing of the DC bus capacitor, load condition, AC input voltage frequency etc determine the 2X AC frequency ripple in the DC bus capacitor. The DC bus capacitor ripple in IRAC1152-350W at 350W is less than 10V as seen in Figure 9 and 10. Figure 9. 2X AC frequency ripple in DC bus capacitor at 85VAC, 350W Figure 10. 2X AC frequency ripple in DC bus capacitor at 264VAC, 350W www.irf.com (c) 2010 International Rectifier 14 IRAC1152-350W Start-up Current Waveforms at 100% load The maximum time for system start-up, about 60msec, is encountered when IRAC1152-350W is powered up at minimum input voltage (85VAC) and maximum output power (350). The soft-start feature of the IC allows for a linear ramp in the VCOMP voltage, which allows a smooth build-up of AC input RMS current admitted into the PFC converter and DC bus capacitor voltage. Note that, prior to entering the soft-start mode, the IC is held under a Brown-out fault condition until VBOP exceeds the Brown-out Protection Enable threshold of 1.7V. Since the PFC voltage loop is a slow loop, the converter goes through a period where the DC bus voltage is under hysteretic OVP condition (between 103% and 106% of regulation voltage set-point) before the VCOMP voltage stabilizes near the steady stage voltage value. 85VAC, 350W 115VAC, 350W 230VAC, 350W 264VAC, 350W www.irf.com (c) 2010 International Rectifier 15 IRAC1152-350W No Load Start-up Current Waveforms 85VAC, 0W 115VAC, 0W 230VAC, 0W 264VAC, 0W www.irf.com (c) 2010 International Rectifier 16 IRAC1152-350W Load Step Waveforms * No-Load to Full-Load Under a 0W to 300W load step at 115VAC, the maximum DC bus voltage undershoot is about 49V; the undershoot at 230Vac is 22V. 115VAC, 0W to 300W load step * 230VAC, 0W to 300W load step Full-load to No-Load 300W to 0W negative load step waveforms are presented below. In all cases, the OVP protection feature is encountered until the DC bus capacitor voltage discharges back to the regulation voltage. 115VAC, 300W to 0W load step 230VAC, 300W to 0W load step www.irf.com (c) 2010 International Rectifier 17 IRAC1152-350W IRAC1152-350W Brown-Out Protection At power up, if AC input voltage is lower than 75Vac, the BOP protection will hold the output of IR1152. Output voltage stays at the peak of input voltage. When AC input exceeds 75Vac, BOP voltage exceeds the BOP enable threshold. IR1152 starts Power Factor correction and VBOP voltage drops to 2/ of its original value. The hysteresis of the BOP prevents any bouncing between On and Off. www.irf.com (c) 2010 International Rectifier 18 2 3 4 D D 1 JT1 AC-IN1 AC+ THERMISTOR 2 C2 R1 C5 C1 C3 470n/275VAC 470k/1W 2 CON3 470n/275VAC N/C 3 470n/275VAC 2 3 2 1 3 3 2 1 1 J1 C L2 4 1 L1 4 C F1 AC-IN2 AC250VAC/6.3A B B R2 1 19 IRAC1152-350W EMI Filter Stage RT1 AC-IN1 IRAC1152-350W Schematics www.irf.com 1 C4 N/C N/C JT2 AC-IN2 A 1 2 3 4 IRAC1152-350W (c) 2010 International Rectifier A www.irf.com 1 2 3 4 5 6 8 7 D1 1N5407-TP D D Vbus C8 150/2W 100P/1kv R7 L3 D5 J7 2 Vout 3 3 1 1 AC+ 500uHY B1 8ETX06 D2 1N4148 J8 JUMPER 1 2 18V Zener FMMT619TA 1 1 JT4 COM + C7 22uf/25v C15 1uf/25v Q1 R8 499K R5 1 B 1 J6 Q4 2 1 J5 2 R23 499K J11 JUMP2 1 U1 1 C13 2 10n 3 R13 4 0 ohm R12 100K 300n GATE COMP VCC ISNS BOP VFB OVP/EN 7 R16 1 IR1152 2 R22 470 ohm JT8 OVP JT9 VFB 1 B N/C R24 13K IRFP22N60K 0 Q2 R17 10K 6 5 J4 1N4148 J9 JUMP2 R21 10k B 1 R26 FMMT720TA J10 JUMP2 13K C14 2 C11 COM 8 C17 Q3 2 2 0.56u J3 E 1.1k R20 1 C JT5 ISNS D7 R19 0 3 R15 BOP 1 1 B CON2 R38 10K C16 1uf/25v 10BQ040 C12 1 JT6 R25 499K 2 1 GATE R10 470k/2w IRFP22N60K R18 0 JT7 D6 R9 499K C9 470n/630v 2 COM R4 3M C CON2 1 D3 0 2 C6 470n/500V C R6 2 2 1 + C10 330uf/450v 1N4148 J2 J15 1 R3 3M 3 C AC- D4 1 2 BRIDGE JT3 VCC 2 1 E 470n/275VAC 4 VCC C5 1 20 IRAC1152-350W Boost PFC Stage 1 JUMPER J12 1000p R11 100 1 GND 0.01/3W (c) 2010 International Rectifier R28 0.01/3w 1 2 3 4 5 6 7 8 A IRAC1152-350W R27 A N/C C18 JUMP2 www.irf.com 1 2 3 4 C19 2.2n/250vAC T1 NC 8 NC L4 D9 8 BYV26-200 J14 21 1N4007 D10 R32 100 3 P6KE150A R30 1.5M C 4 3 2 5 C23 10n/1kv R31 1K 6 1 TRANS7 2 D13 R34 20 1 2 EN/UV S BP/M S S C25 100n/50v 4 D U3 S COM1 UF4003 C 1uf/60v R35 D14 BZX79/15V 47/1/8W R33 D11 1N4007 B C21 R29 22uf/50V 12K/1W C24 1N5255/28V 22uf/400v VCC 5 D12 + C22 C20 N/C 6 4 2 1 IRAC1152-350W Flyback SMPS Stage 1 D J13 1 D8 Vbus SHORT 2 D 21K R36 390/1/8W 8 B 7 6 5 U2 TNY278P GND R37 2K/1/8W PC817A A (c) 2010 International Rectifier 1 2 3 4 IRAC1152-350W A IRAC1152-350W IRAC1152-350W Bill of Materials (BoM) NO. 1 2 3 PART TYPE BN PCB Bridge Discrete Capacitor PART DESCRIPTION PCB, IR1152-350W_V4.0 RECT BRIDGE GPP 600V 8A GBU CAP THR, 0.47UF 250/275VAC ECQ-UL 4 Electrolytic Capacitor CAP THA, 330uF AL ELEC 450V 20%---40*35*10 5 6 7 8 9 10 11 Chip Capacitor Chip Capacitor Chip Capacitor Chip Capacitor Chip Capacitor Discrete Capacitor Electrolytic Capacitor 12 Electrolytic Capacitor 13 14 15 Discrete Capacitor Electrolytic Capacitor Discrete Capacitor 16 Tantalum capacitor 17 Discrete Capacitor 18 Diode 19 20 Diode Diode 21 22 Diode Diode 23 Diode 24 Diode 25 Diode 26 27 28 29 30 31 Diode Diode Diode Fuse base Connector Wire CAP SMT, 1000pF 1206 CER 50V 10% X7R CAP SMT, 0.56uF 1206 CER 50V 10% X5R CAP SMT, 10000pF 1206 CER 50V 10% X7R CAP SMT, 0.1uF 1206 CER 50V 10% X7R CAP SMT, 1uF 1210 CER 50V 10% X5R CAP THR, 2.2nF 400V, 20%, Disc Y1 Cera-Mite 440LD22 CAP THR, 22uF, AL ELEC, 50V (2mmLS)--11.5*5*2.5 CAP THR, 22 F, 400 V, Electrolytic, Low ESR, 901 m, (20 x 16x7.5) CAP THR, 10 nF, 1 kV, 20%, Disc Ceramic Vishay/Sprague 562R5HKMS10 CAP THR, 1uF,ELEC 50V 20%---11*5*2 105 C CAP THR, 0.47uF CER 630V 10% Panasonic ECQ-E6474KF DIGIKEY EF6474-ND CAP SMT, 22uF 7343-31 TANT 35V 20% PANASONIC EEJ-L1VD226R DIGIKEY P11302CT-ND CAP THR, 100PF 1KVDC CERAMIC SL/GP 5% LS=5mm Panasonic ECC-D3A101JGE DIGIKEY P10804-ND DIODE, RECTIFIER GPP 800V 3A DO-201AD DIODES 1N5407-T DIGIKEY 1N5407DICT-ND DIODE, TVS 150V 600W 5% UNI AXL MOUSER 625-P6KE150A-E3 DIODE, STANDARD 1N4007 50V 1A DO-41---DO- YJ--1N4007 41 DIODE, Zener Diode 36V MOUSER 512-1N5258B DIODE, GPP FAST 1A 200V DO-41 Fairchild UF4003 DIGIKEY UF4003-ND DIODE, ZENER 15V 1W 5% DO-41 DIODES 1N4744A-T DIGIKEY 1N4744ADICT-ND DIODE SMT, FAST SWITCHING 100V 5uA 500mW DIODES INC LL4148 MINI-MELF DL-35 DIGIKEY LL4148DITR-ND DIODE SMT, ZENER 500MW 18V SOD-123 DIODES BZT52C18-7-F DIGIKEY BZT52C18-FDICT-ND DIODE, HYPERFAST 600V 8A TO-220AC DIGIKEY 8ETX06PBF-ND DIODE SMT, SCHOTTKY 40V 1A SMB DIGIKEY 10BQ040-ND DIODE, GPP 3A 200V HI EFF DO-201AE DIGIKEY EGP30D-TPCT-ND 32 33 Wire Connector 34 Test point 35 36 37 Inductor Inductor NPN Transistor 38 PNP Transistor 39 MOSFET 40 41 42 43 44 45 46 Discrete resistor Chip Resistor Chip Resistor Chip Resistor Chip Resistor Chip Resistor Chip Resistor QTY MANUFACTURER & PART# 1 1 3 YJ GBU806 Panasonic ECQ-U2A474ML DIGIKEY P10734-ND SAMWHA HE 450V 330UF 35*40 P=10 1 JIANGHAI HE 450V 330UF 35*40 P=10 CONN, HDR, 3P, WIRE, 24 AWG,AWM1007 WIRE, 16 AWG,AWM1007 CONN, HDR, 1x2, 0.100" PITCH, 0.025 SQ POST, TIN (0.135"/0.380") KEYED MOLEX 22-23-2021 DIGIKEY WM4200-ND KEYSTONE 5007 DIGIKEY 5007K-ND EMI Common Mode Choke 7A 10mH TNC KOREA CV507100BS 600uH Boost Inductor custom designed by Precision Precision 019-4894-01R proto-2 Inc DIODE SMT, NPN 50V 2000MA SOT-23 Zetex FMMT619TA DIGIKEY FMMT619CT-ND DIODE SMT, PNP -40V -1500MA SOT-23 Zetex FMMT720TA DIGIKEY FMMT720CT-ND TRANS, MOSFET N-CHAN 600V 20A TO-247 Fairchild FCH20N60 DIGIKEY FCH20N60-ND RES, MF 470K-OHM 1W 5% RES SMT, 100-OHM 1/4W 1% 1206 RES SMT, 100K-OHM 1/4W 5% 1206 RES SMT, 0-OHM 1/4W 5% 1206 RES SMT, 1.1K-OHM 1/4W 1% 1206 RES SMT, 10K-OHM 1/4W 1% 1206 RES SMT, 5.1-OHM 1/4W 1% 1206 www.irf.com DESIGNATOR B1 C1,C2,C5 C10 1 1 1 2 2 1 1 C11 C12 C13 C14,C25 C15,C16 C19 C21 1 C22 1 1 2 C23 C24 C6,C9 1 C7 1 C8 1 D1 1 2 D10 D8,D11 1 1 D12 D13 1 D14 3 D2,D4,D7 1 D3 1 1 1 2 2 0.25 D5 D6 D9 F1 J1,J6 J2,J4,J5,J9,J10,J11,J12,J13 ,J14,J17,L4 J7,J8 J15 0.08 1 7 2 1 1 L1,L2 L3 Q1 1 Q2 2 Q3,Q4 2 1 1 3 1 3 1 R1,R10 R11 R12 R13,R16,R19 R15 R17,R21,R38 R18 (c) 2010 International Rectifier 22 IRAC1152-350W NO. 47 48 49 50 51 PART TYPE Chip Resistor Chip Resistor Chip Resistor Chip Resistor Discrete resistor PART DESCRIPTION RES SMT, 1.5-OHM 1/4W 1% 1206 RES SMT, 3.9-OHM 1/4W 1% 1206 RES SMT, 1M-OHM 1/4W 1% 1210 RES SMT, 26.1K-OHM 1/4W 1% 1206 RES, 50m-ohm CURRENT SENSE RESISTOR 5W 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 Chip Resistor Discrete resistor Discrete resistor Chip Resistor Discrete resistor Chip Resistor Discrete resistor Chip Resistor Chip Resistor Chip Resistor Discrete resistor Discrete resistor Transformer IC Diode IC 68 69 70 71 Fuse Fuse Cover Heatsink 72 Heatsink 73 Clip 74 Clip RES SMT, 3M-OHM 1/4W 1% 1206 RES, CF 12K-OHM 1W 5% RES, CF1.5M-OHM 1/2W 5% RES SMT, 1.0K-OHM 1/4W 1% 1206 RES, CF 100-OHM 1/4W 5% RES SMT, 21K-OHM 1/4W 1% 1206 RES, CF 20-OHM 1/4W 5% RES SMT, 47-OHM 1/4W 1% 1206 RES SMT, 390-OHM 1/4W 1% 1206 RES SMT, 2.0K-OHM 1/4W 1% 1206 RES, MF 150-OHM 2W 5% CURRENT LIMITER INRUSH 6A STEADY STATE EE25V Switch transformer IC, PFC Control IC IR1152---SO-8 DIODE, PHOTOCOUPLER TRAN OUT 4-DIP IC, SWITCH OFF-LINE 10/28W TNY278PN---8P DIP UNINSTALLED PARTS FUSE 6.3A/250V 5X20MM FAST Vinyl Fuse Cover HEATSINK, IRAC1152-350W Heatsink for Boost FET/Diode---160mm length HEATSINK, IRAC1152-350W Heatsink for Bridge rectifier---76mm length HEATSINK CLIP, Aavid MAX Clip 03 for TO-247 for Q3, Q4 & B1 HEATSINK CLIP, Aavid MAX Clip 01 for TO-220 for D5 75 76 77 78 79 80 81 82 83 84 Screw Spring Washer Washer Standoff Insulation Pad Insulation Pad Screw Standoff Label Anti-static Bag QTY 2 2 4 2 1 DESIGNATOR R5,R20 R6,R22 R8,R9,R23,R25 R24,R26 R27 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 R3,R4 R29 R30 R31 R32 R33 R34 R35 R36 R37 R7 RT1 T1 U1 U2 U3 1 1 1 C17,C18,C20,C3,C4,R2,R28, J3 F1 MANUFACTURER & PART# HMR KOREA 50mohm,MPR-5R(S) series,TWO LEAD TYPE DIGIKEY KC004L-ND SANTRONICS SNX-1380 IR IR1152S SHARP--PC817X2 Power Integrations TNY278PN DIGIKEY 596-1094-5-ND DIGIKEY F953-ND DIGIKEY 3527CK-ND AAVID 78195(160mm) AAVID 78195(76mm) 1 AAVID MAX03(406097) MOUSER 532-MAXCLIP03 AAVID MAX01(406098) MOUSER 532-MAXCLIP01 3 1 5 5 5 5 1 2 5 5 1 1 For D5 (TO-220) For Q3 & Q4 (TO-3P, 25X19) HW, SPACER, M3 x 18mm,NYLON---M3*18 LABEL, 22.86x6.35 400x300 www.irf.com (c) 2010 International Rectifier 23 IRAC1152-350W IRAC1152-350W PCB & Component Layout The information provided in this document is believed to be accurate and reliable. However, International Rectifier assumes no responsibility for the consequences of the use of this information. International Rectifier assumes no responsibility for any infringement of patents or of other rights of third parties which may result from the use of this information. No license is granted by implication or otherwise under any patent or patent rights of International Rectifier. The specifications mentioned in this document are subject to change without notice. This document supersedes and replaces all information previously supplied. For technical support, please contact IR's Technical Assistance Center http://www.irf.com/technical-info/ WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245 Tel: (310) 252-7105 www.irf.com (c) 2010 International Rectifier 24 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: International Rectifier: IRAC1152-350W