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| rev. page date 1 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter features * industry standard pin out * high efficiency to 94% * 300 KHz switching frequency * 9.0-14 VDC wide input range * 0.75-5.0 VDC wide output range * over temperature protection * continuous short circuit protection * remote on/off * cost-efficient open frame design * UL/C-UL60950-1 (E222736) certified Content 1. INTRODUCTION 2. VPOL16A-12-SIP CONVERTER FEATURES 3. GENERAL DESCRIPTION 3.1 Electrical Description 3.2 Thermal Packaging and Physical Design. 4. TECHNICAL SPECIFICATIONS 5. MAIN FEATURES AND FUNCTIONS 5.1 Operating Temperature Range 5.2 Over-Temperature Protection (OTP) 5.3 Output Voltage Adjustment 5.4 Safe Operating Area (SOA) 5.5 Over Current Protection 5.6 Remote ON/OFF 5.7 UVLO (Under-Voltage Lockout) 6. SAFETY 6.1 Input Fusing and Safety Considerations. 7. APPLICATIONS 7.1 Layout Design Challenges. 7.2 Convection Requirements for Cooling 7.3 Thermal Considerations 7.4 Power De-Rating Curves 7.5 Efficiency vs Load Curves 7.6 Input Capacitance at the Power Module 7.7 Test Set-Up 7.8 Remote Sense Compensation 7.8 VPOL16A-12-SIP Series Output Voltage Adustment. 7.9 Output Ripple and Noise Measurement 7.10 Output Capacitance 7.11 VPOL16A-12-SIP Reflow Profile 8. MECHANICAL OUTLINE DIAGRAMS 8.1 VPOL16A-12-SIP Mechanical Outline Diagrams 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 2 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter The converter is also protected against over-temperature conditions. If 1. Introduction This application note describes the features and functions of V-Infinity's VPOL16A-12-SIP series of Non Isolated DC-DC Converters. These are highly efficient, reliable and compact, high power density, single output DC/DC converters. These "Point of Load" modules serve the needs specifically of the fixed and mobile telecommunications and computing market, employing economical distributed Power Architectures. The VPOL16A-12-SIP series provide precisely regulated output voltage range from 0.75V to 5.0Vdc over a wide range of input voltage (Vi=9.0 - 14Vdc) and can operate over an ambient temperature range of -40C to +85C. Ultr a-high efficiency operation is achieved through the use of synchronous rectification and drive control techniques. The modules are fully protected against short circuit and overtemperature conditions. V-Infinity's world class automated manufacturing methods, together with an extensive testing and qualification program, ensure that all VPOL16A-12-SIP series converters are extremely reliable. the converter is overloaded or the ambient temperature gets too high, the converter will shut down to protect the unit. Q1 +VIN L1 +VO C1 Q2 D1 C2 R sense +SENSE COM COM R1 PWM IC ON/OFF R trim TRIM ERR AMP R2 Figure 1. Electrical Block Diagram 3.2 Thermal Packaging and Physical Design. The VPOL16A-12-SIP series uses a multi-layer FR4 PCB construction. All surface mount power components are placed on one side of the PCB, and all low-power control components are placed on the other side. Thus, the Heat dissipation of the power components is optimized, ensuring that control components are not thermally stressed. The converter is an open-frame product and has no case or case pin. The open-frame design has several advantages over encapsulated closed devices. Among these advantages are: Efficient Thermal Management: the heat is removed from the heat generating components without heating more sensitive, small signal control components. Environmental: Lead free open-frame converters are more easily re-cycled. Cost Efficient: No encapsulation. Cost efficient open-frame construction. Reliable: Efficient cooling provided by open frame construction offers high reliability and easy diagnostics. 2. VPOL16A-12-SIP Converter Features High efficiency topology, typically 94% at 5.0Vdc Industry standard footprint Wide ambient temperature range, -40C to +85C Cost efficient open frame design Programmable output voltage via external resistor from 0.75 to 5.0Vdc No minimum load requirement (Stable at all loads) Remote ON/OFF Remote sense compensation Fixed switching frequency Continuous short-circuit protection and over current protection Over-temperature protection (OTP) Monotonic Startup with pre-bias at the output. UL/IEC/EN60950 Certified. 3. General Description 3.1 Electrical Description A block diagram of the VPOL16A-12-SIP Series converter is shown in Figure 1. Extremely high efficiency power conversion is achieved through the use of synchronous rectification and drive techniques. Essentially, the powerful VPOL16A-12-SIP series topology is based on a non-isolated synchronous buck converter. The control loop is optimized for unconditional stability, fast transient response and a very tight line and load regulation. In a typical pre-bias application the VPOL16A-12-SIP series converters do not draw any reverse current at start-up. The output voltage can be adjusted from 0.75 to 5.0vdc, using the TRIM pin with a external resistor. The converter can be shut down via a remote ON/OFF input that is referenced to ground. This input is compatible with popular logic devices; a 'positive' logic input is supplied as standard. Positive logic implies that the converter is enabled if the remote ON/OFF input is high (or floating), and disabled if it is low. 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 3 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter 4. Technical Specifications (All specifications are typical at nominal input, full load at 25C unless otherwise noted.) Device PARAMETER NOTES and CONDITIONS ABSOLUTE MAXIMUM RATINGS Input Voltage Continuous Operating Temp erature See Thermal Considerations Section Storage Temperature ALL ALL ALL Min. Typical Max. Units 0 -40 -55 15 +85 +125 Vdc C C INPUT CHARACTERISTICS Operating Input Voltage Input Under-Voltage Lockout Turn-On Voltage Threshold Turn-Off Voltage Threshold Lockout Hysteresis Voltage Maximum Input Current Vin=0 to 14Vdc , Io=Io,max. Vo=0.75V Vo=1.2V Vo=1.5V Vo=1.8V Vo=2.0V Vo=2.5V Vo=3.3V Vo=5.0V Shutdown input idle current ALL ALL ALL ALL ALL 9.0 8.0 7.7 0.3 11 40 50 50 60 60 65 75 75 10 0.1 300 12 14 Vdc Vdc Vdc Vdc A No-Load Input Current ALL mA Off Converter Input Current Inrush Current (I t) Input Reflected-Ripple Current 2 ALL ALL mA As mA 2 P-P thru 1uH inductor, 5Hz to 20MHz ALL OUTPUT CHARACTERISTIC Output Voltage Set Point Output Voltage Trim Adjustment Range Output Voltage Regulation Load Regulation Line Regulation Tempera ture Coefficient Output Voltage Ripple and Noise Peak-to-Peak RMS External Capacitive Load Operating Output Current Range Output DC Current-Limit Inception Shout Circuit Protection Output Voltage =90% Nominal Output Voltage Continuous with Hiccup Mode Io=Io.min to Io.max Vin=low line to high line Ta=-40C to 85C 5Hz to 20MHz bandwidth Full Load, 1uF ceramic and 10uF tantalum Full Load, 1uF ceramic and 10uF tantalum Low ESR ALL ALL ALL ALL ALL ALL 0 18 23 75 30 8000 16 28 mV mV uF A A ALL ALL ALL -0.5 -0.2 -0.03 +0.5 +0.2 +0.03 % % %/C Vin=Nominal Vin , Io=Io.max, Tc=25 Selected by an external resistor ALL ALL -1.5% Vo,set +1.5% 0.75 5.0 Vdc Vdc 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 4 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter PARAMETER DYNAMIC CHARACTERISTICS Output Voltage Transient Response Error Brand Setting Time (within 1% Vout nominal) NOTES and CONDITIONS Device Min. Typical Max. Units 50% Step Load Change, di/dt=0.1A/us 50% Step Load Change, di/dt=0.1A/us ALL ALL 200 200 mV us EFFICIENCY Vo=0.75V Vo=1.2V Vo=1.5V Vo=1.8V Vo=2.0V Vo=2.5V Vo=3.3V Vo=5.0V Non-isolation 77 83 86 88 89 90 92 94 0 100% Load ALL % ISOLATION CHARACTERISTICS Input to Output ALL Vdc FEATURE CHARACTERISTICS Switching Frequency ON/OFF Control, Positive Logic Remote On/Off Logic Low (Module Off) Logic High (Module On) ALL 0 Vin 0 2.8 0.4 Vin 1 1 3.5 3.5 3.5 130 0.98 10 300 0.4 KHz Vdc Vdc Vdc Vdc mA mA ms ms ms C M hours grams or Open Circuit VPOL16A-12-SIP ON/OFF Control, Negative Logic Remote On/Off or Open Circuit Logic Low (Module On) Logic High (Module Off) ON/OFF Current (for both remote on/off logic) Leakage Current (for both remote on/off logic) Turn-On Delay and Rise Time Turn-On Delay Time, From On/Off Control Turn-On Delay Time, From Input Output Voltage Rise Time Over Temperature Protection Ion/off at Von/off =0.0V Logic High, Von/off=14V Von/off to 10%Vo,set Vin,min. to 10%Vo,set 10%Vo,set to 90%Vo,set VPOL16A-12-SIP ALL ALL ALL ALL ALL ALL ALL ALL GENERAL SPECIFICATIONS MTBF Weight Dimensions VPOL16A-12-SIP packages Io=100%of Io.max;Ta=2 5C per MIL-HDBK217F 2x0.512x0.327 inches (50.8x13.0x8.3 mm) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 5 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter +Vin Remote ON/OFF +Vo 7. Applications 7.1 Layout Design Challenges. In optimizing thermal design the PCB is utilized as a heat sink. Also some heat is transferred from the VPOL16A-12-SIP module to the main board through connecting pins. The system designer or the end user must ensure that other components and metal in the vicinity of the VPOL16A-12-SIP series meet the spacing requirements to which the system is approved. Low resistance and low inductance PCB layout traces are the norm and should be used where possible. Due consideration must also be given to proper low impedance tracks between power module, input and output grounds. The recommended VPOL16A-12-SIP footprint is shown as figure 5. ON/OFF Control Q1 VPOL16A-12-SIP Common Common Figure 3. Positive Remote ON/OFF Input Drive Circuit +Vin +Vo Q1 ON/OFF Control VPOL16A-12-SIP Remote ON/OFF 0.29(7.4) Common Common LAYOUT PATTERN TOP VIEW 0.33(8.4) Figure 4. Negative Remote ON/OFF Input Drive Circuit All Dimmension In Inches(mm) Tole rance : .XX= 0.04 .XXX= 0.010 1.1mm PLATED THROUGH HOLE 1.6mm PAD SIZE 5.7 UVLO (Under-Voltage Lockout) The voltage on the Vcc pin determines the start of the operation of the Converter. When the input Vcc rises and exceeds about 8.0V the converter initiates a soft start. The UVLO function in the converter has a hysteresis (about 300mV) built in to provide noise immunity at start-up. Figure 5. Recommended VPOL16A-12-SIP Footprint 6. Safety 6.1 Input Fusing and Safety Considerations. Agency Approvals: The power Supply shall be submitted to and receive formal approval from the following test agencies. 1.The power supply shall be approved by a nationally recognized testing laboratory to UL/CSA 60950 3 Edition (North America) and EN60950 (International) 2. CB Certificate from an internationally recognized test house in accordance with EN 60950. The VPOL16A-12-SIP series converters do not have an internal fuse. However, to achieve maximum safety and system protection, always use an input line fuse. The safety agencies require a time-delay fuse with a maximum rating of 20A. rd 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 6 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter 7.2 Convection Requirements for Cooling To predict the ap proximate cooling needed for the module, refer to the Power De-rating curves in Figures 8 & 9 . These de-rating curves are approximations of the ambient temperatures and airflows required to keep the power module temperature below its maximum rating. Once the module is assembled in the actual system, the module's temperature should be checked as shown in Figure 6 to ensure it does not exceed 120C. Proper cooling can be verified by measuring the power module's temperature at Q1-pin 6 as shown in Figure 7. W ind Tunnel Bakelite 7.3 Thermal Considerations The power module operates in a variety of thermal environments; however, sufficient cooling should be provided to help ensure reliable operation of the unit. Heat is removed by conduction, convection, and radiation to the surrounding environment. The thermal data presented is based on measurements taken in a set-up as shown in Figure 6. Figures 8 & 9 represent the test data. Note that the airflow is parallel to the long axis of the module as shown in Fig 6 for the VPOL16A-12-SIP. The temperature at either location should not exceed 120 C. The output power of the module should not exceed the rated power for the module (VO, set x IO, max). The VPOL16A-12-SIP thermal data presented is based on measurements taken in a wind tunnel. The test setup shown in Figure 7 and EUT need to solder on 33mm x 40.38mm(1.300'' x 1.59'') test pcb. Note that airflow is parallel to the long axis of the module as shown in Fig 6. 25.4(1.0) Power Module 76.2(3.0) Thermocuple Location for measuring ambient temperature and airflow 12.7(0.5) Air flow Note : Dimensions are in millimeters and (inches) Figure 6. Thermal Test Setup Figure 7. Temperature Measurement Location for VPOL16A12-SIP 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 7 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter TYPICAL POWER DERATING FOR 5 Vin 3.3 Vout 18 16 14 Output Current(A) 12 10 8 6 4 2 0 0 10 20 30 40 50 60 70 80 90 100 0LFM 100LFM 200LFM 300LFM Ambient Temperature( oC) NOTE: 1. specific input & output derating curves available, please contact V-Infinity for detail 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 8 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter 7.5 Efficiency vs Load Curves (Fig. 9) VPOL16A-12-SIP Vo=5.0V (Eff Vs Io) 100% 95% 100% 95% VPOL16A-12-SIP Vo=3.3V (Eff Vs Io) Efficincy (%) 90% 85% 80% 75% 70% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Efficincy (%) 90% 85% 80% 75% 70% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 9.0V 12V 14V 9.0V 12V 14V Current Load (A) VPOL16A-12-SIP Vo=2.5V (Eff Vs Io) 100% 95% 100% 95% 90% Current Load (A) VPOL16A-12-SIP Vo=2.0V (Eff Vs Io) Efficincy (%) 90% 85% 80% 75% 70% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Efficincy (%) 85% 80% 75% 70% 65% 60% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 9.0V 12V 14V 9.0V 12V 14V Current Load (A) Current Load (A) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 9 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter VPOL16A-12-SIP Vo=1.8V (Eff Vs Io) 100% 95% 90% 100% 95% 90% VPOL16A-12-SIP Vo=1.5V (Eff Vs Io) Efficincy (%) 85% 80% 75% 70% 65% 60% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Efficincy (%) 85% 80% 75% 70% 65% 60% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 9.0V 12V 14V 9.0V 12V 14V Current Load (A) VPOL16A-12-SIP Vo=1.2V (Eff Vs Io) 100% 95% 90% 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0 1 2 3 4 Current Load (A) VPOL16A-12-SIP Vo=0.75V (Eff Vs Io) Efficincy (%) 85% 80% 75% 70% 65% 60% 9.0V 12V 14V Efficincy (%) 9.0V 12V 14V 5 6 7 8 9 10 11 12 13 14 15 16 Current Load (A) Current Load (A) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 10 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter Where: 7.6 Input Capacitance at the Power Module The VPOL16A-12-SIP converters must be connected to a low AC source impedance. To avoid probl ems with loop stability source inductance should be low. Also, the input capacitors should be placed close to the converter input pins to de-couple distribution inductance. However, the external input capacitors are chosen for suitable ripple handling capability. Low ESR polymers are a good choice. They have high capacitance, high ripple rating and low ESR (typical <100mohm). Electrolytic capacitors should be avoided. Circuit as shown in Figure 10 represents typical measurement methods for ripple current. Input reflected-ripple current is measured with a simulated source Inductance of 1uH. Current is measured at the input of the module. Power Supply + VFL is the output voltage at full load VNL is the output voltage at no load The value of line regulation is defined as: Line.reg= VHL _ VLL x 100% VLL Where: VHL is the output voltage of maximum input voltage at full load. VLL is the output voltage of minimum input voltage at full load. Current Meter A +Vin +Vo +Sense A V 100uF Voltage Meter VPOL16A-12-SIP Common Common V Load To Oscilloscope L1 1uH Power Supply + 2*100uF Tantalum 220uF ESR<0.1ohm Common Figure 10. Input Reflected-Ripple Test Setup +Vin Figure 11. VPOL16A-12-SIP Series Test Setup 7.8 Remote Sense Compensation VPOL16A-12-SIP Remote Sense regulates the output voltage at the point of load. It minimizes the effects of distribution losses such as drops across the connecting pin and PCB tracks (see Figure 12). Please note however, the maximum drop from the output pin to the point of load should not exceed 500mV for remote compensation to work. The amount of power delivered by the module is defined as the output voltage multiplied by the output current (VO x IO). When using TRIM UP, the output voltage of the module will increase which, if the same output current is maintained, increases the power output by the module. Make sure that the maximum output power of the module remains at or below the maximum rated power. When the Remote Sense feature is not being used, leave sense pin disconnected. 7.7 Test Set-Up The basic test set-up to measure parameters such as efficiency and load regulation is shown in Figure 11. Things to note are that this converter is non-isolated, as such the input and output share a common ground. These grounds should be connected together via low impedance ground plane in the application circuit. When testing a converter on a bench set-up, ensure that -Vin and -Vo are connected together via a low impedance short to ensure proper efficiency and load regulation measurements are being made. When testing the V-Infinity's VPOL16A-12-SIP series under any transient conditions please ensure that the transient response of the source is sufficient to power the equipment under test. We can calculate the Efficiency Load regulation and line regulation. The value of efficiency is defined as: Figure 12. Circuit Configuration for Remote Sense Operation Distribution Losses +Vin +Vo +Sense R-Load Vo x Io x 100% c= Vin x Iin Common Where: Vo is output voltage, Io is output current, Vin is input voltage, Iin is input current. The value of load regulation is defined as: Common Distribution Losses Load .reg= VFL _ VNL x 100% VNL 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 11 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter 7.8 VPOL16A-12-SIP Series Output Voltage Adustment. The output Voltage of the VPOL16A-12-SIP can be adjusted in the range 0.75V to 5.0V by connecting a single resistor on the motherboard (shown as Rtrim) in Figure 13. When Trim resistor is not connected the output voltage defaults to 0.75V 7.9 Output Ripple and Noise Measurement The test set-up for noise and ripple measurements is shown in Figure 14. a coaxial cable with a 50ohm termination was used to prevent impedance mismatch reflections disturbing the noise readings at higher frequencies. +Vin +Vo +Vin +Vo VPOL16A-12-SIP 10uF Tant. 1uF Ceramic R-Load Test Jack Trim R-Load VPOL16A-12-SIP R trim-up Common Common Figure 14. Output Voltage Ripple and Noise Measurement Set-Up Common Common 7.10 Output Capacitance Figure 13. Trim-up Voltage Setup The value of Rtrim-up defined as: V-Infinity's VPOL16A-12-SIP series converters provide unconditional stability with or without external capacitors. For good transient response low ESR output capacitors should be located close to the point of load. For high current applications point has already been made in layout considerations for low resistance and low inductance tracks. Output capacitors with its associated ESR values have an impact on loop stability and bandwidth. V-Infinity's converters are designed to work with load capacitance up-to 8,000uF. It is reco mmended that any additional capacitance, Maximum 8,000uF and low ESR, be connected close to the point of load and outside the remote compensation point. 10500 _ Rtrim = ( _ 1000 ) Vo 0.75 Where: Rtrim-up is the external resistor in ohm, Vo is the desired output voltage To give an exa mple of the above calculation, to set a voltage of 3.3Vdc, Rtrim is given by: Rtrim = ( Rtrim = 3117 ohm 10500 _ 1000 ) _ 3.3 0.75 7.11 VPOL16A-12-SIP Reflow Profile An example of the VPOL16A-12-SIP reflow profile is given in Figure 15. Equipment used: SMD HOT AIR REFLOW HD-350SAR Alloy: AMQ-M293TA or N C-SMQ92 IND-82088 SN63 For various output values various resistors are calculated and provided in Table 3 for co nvenience. REFLOW PROFILE 240 Vo,set (V) 0.75 1.20 1.50 1.80 2.00 2.50 3.30 5.0 Rtrim (Kohm) Open 22.33 13.0 9.0 7.4 5.0 3.12 1.47 200 TEMPERATURE (C) 160 120 80 40 0 0 30 60 90 120 150 180 210 240 TIME (SECONDS) Table 3 - Trim Resistor Values Figure 15 VPOL16A-12-SIP Reflow Profile 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page date 12 of 12 11/2007 PART NUMBER: VPOL16A-12-SIP DESCRIPTION: point of load converter 8. Mechanical Outline Diagrams 8.1 VPOL16A-12-SIP Mechanical Outline Diagrams Dimensions are in millimeters and inches Tolerance: x.xx 0.02 in. (0.5mm) , x.xxx 0.010 in. (0.25 mm) unless otherwise noted Pin Connection SIZE VPOL16A-12-SIP 2.00(50.8) 0.327(8.30)max. 0.23(5.8) 12345 0.14(3.6) 0.100(2.54) 0.400(10.20) 0.010(0.25) min. 0.025(0.64) 1.000(25.40) 6 7 8 9 10 11 0.512(13.00) 0.28(7.1) 0.025(0.64) 0.050(1.30) Pin 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Function +output +output +sense +output common no pin / pgood common +v input +v input sequency trim on/off control Figure 19 VPOL16A-12-SIP Mechanical Outline Diagram 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 |
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