rev. page 1 of 12 date 11/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP 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 7. APPLICATIONS 7.1 Layout Design Challenges. 3. GENERAL DESCRIPTION 3.1 Electrical Description 7.2 Convection Requirements for Cooling 3.2 Thermal Packaging and Physical Design. 7.4 Power De-Rating Curves 4. TECHNICAL SPECIFICATIONS 7.5 Efficiency vs Load Curves 5. MAIN FEATURES AND FUNCTIONS 5.1 Operating Temperature Range 7.6 Input Capacitance at the Power Module 5.2 Over-Temperature Protection (OTP) 7.8 Remote Sense Compensation 5.3 Output Voltage Adjustment 7.8 VPOL16A-12-SIP Series Output Voltage Adustment. 5.4 Safe Operating Area (SOA) 7.9 Output Ripple and Noise Measurement 5.5 Over Current Protection 7.10 Output Capacitance 5.6 Remote ON/OFF 7.11 VPOL16A-12-SIP Reflow Profile 5.7 UVLO (Under-Voltage Lockout) 6. SAFETY 6.1 Input Fusing and Safety Considerations. 7.3 Thermal Considerations 7.7 Test Set-Up 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. PART NUMBER: VPOL16A-12-SIP page 2 of 12 date 11/2007 DESCRIPTION: point of load converter The converter is also protected against over-temperature conditions. If 1. Introduction the converter is overloaded or the ambient temperature gets too high, the converter will shut down to protect the unit. This application note describes the features and functions of V-Infinity’s VPOL16A-12-SIP series of Non Isolated DC-DC Converters. These are L1 Q1 +VIN +VO highly efficient, reliable and compact, high power density, single output DC/DC converters. These “Point of Load” modules serve the needs Q2 C1 specifically of the fixed and mobile telecommunications and computing D1 C2 R sense +SENSE 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 – COM COM 14Vdc) and can operate over an ambient temperature range of –40°C R1 PWM IC to +85°C. Ultra-high efficiency operation is achieved through the use of synchronous rectification and drive control techniques. ON/OFF R trim TRIM ERR AMP R2 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 Figure 1. Electrical Block Diagram qualification program, ensure that all VPOL16A-12-SIP series converters are extremely reliable. 2. VPOL16A-12-SIP Converter Features High efficiency topology, typically 94% at 5.0Vdc Industry standard footprint Wide ambient temperature range, -40°C to +85°C Cost efficient open frame design Programmable output voltage via external resistor from 0.75 to 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: 5.0Vdc Efficient Thermal Management: the heat is removed from the No minimum load requirement (Stable at all loads) heat generating components without heating more sensitive, small Remote ON/OFF signal control components. Remote sense compensation Environmental: Lead free open-frame converters are more easily Fixed switching frequency re-cycled. Continuous short-circuit protection and over current protection Cost Efficient: No encapsulation. Cost efficient open-frame Over-temperature protection (OTP) construction. Monotonic Startup with pre-bias at the output. Reliable: Efficient cooling provided by open frame construction UL/IEC/EN60950 Certified. offers high reliability and easy diagnostics. 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 3 of 12 date 11/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP 4. Technical Specifications (All specifications are typical at nominal input, full load at 25°C unless otherwise noted.) Device PARAMETER NOTES and CONDITIONS ABSOLUTE MAXIMUM RATINGS Input Voltage Continuous Operating Temp erature See Thermal Considerations Section Min. Typical Max. Units ALL 0 15 Vdc ALL -40 +85 °C ALL -55 +125 °C ALL 9.0 14 Vdc Storage Temperature INPUT CHARACTERISTICS Operating Input Voltage Input Under-Voltage Lockout Turn-On Voltage Threshold Turn-Off Voltage Threshold Lockout Hysteresis Voltage ALL ALL ALL ALL 12 8.0 Vdc Vdc Vdc 7.7 0.3 Maximum Input Current Vin=0 to 14Vdc , Io=Io,max. No-Load Input Current Vo=0.75V Vo=1.2V Vo=1.5V Vo=1.8V Vo=2.0V Vo=2.5V Vo=3.3V Vo=5.0V ALL Off Converter Input Current Shutdown input idle current ALL 10 mA ALL 0.1 As 2 Inrush Current (I t) Input Reflected-Ripple Current 11 40 50 50 60 60 65 75 75 A mA 2 P-P thru 1uH inductor, 5Hz to 20MHz ALL 300 mA Output Voltage Set Point Vin=Nominal Vin , Io=Io.max, Tc=25 ALL -1.5% Vo,set +1.5% Vdc Output Voltage Trim Adjustment Range Selected by an external resistor ALL OUTPUT CHARACTERISTIC 0.75 5.0 Vdc Output Voltage Regulation Load Regulation Io=Io.min to Io.max ALL -0.5 +0.5 % Line Regulation Vin=low line to high line ALL -0.2 +0.2 % Tempera ture Coefficient Ta=-40°C to 85°C ALL -0.03 +0.03 %/°C Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth 75 mV Peak-to-Peak RMS External Capacitive Load Full Load, 1uF ceramic and 10uF tantalum ALL Full Load, 1uF ceramic and 10uF tantalum ALL 30 mV Low ESR ALL 8000 uF 16 A 28 A Operating Output Current Range ALL 0 18 Output DC Current-Limit Inception Output Voltage =90% Nominal Output Voltage ALL Shout Circuit Protection Continuous with Hiccup Mode ALL 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 23 rev. 4 of 12 date 11/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP PARAMETER DYNAMIC CHARACTERISTICS page NOTES and CONDITIONS Device Min. Typical Max. Units Output Voltage Transient Response Error Brand 50% Step Load Change, di/dt=0.1A/us ALL 200 mV Setting Time (within 1% Vout nominal) 50% Step Load Change, di/dt=0.1A/us ALL 200 us EFFICIENCY 100% Load Vo=0.75V Vo=1.2V Vo=1.5V Vo=1.8V Vo=2.0V Vo=2.5V Vo=3.3V Vo=5.0V ALL Non-isolation ALL 77 83 86 88 89 90 92 94 % ISOLATION CHARACTERISTICS Input to Output 0 Vdc FEATURE CHARACTERISTICS Switching Frequency ON/OFF Control, Positive Logic Remote On/Off Logic Low (Module Off) Logic High (Module On) ALL or Open Circuit 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 VPOL16A-12-SIP VPOL16A-12-SIP 300 0 KHz 0.4 Vdc Vdc 0.4 Vin Vdc Vdc 1 1 mA mA Vin 0 2.8 Ion/off at Von/off =0.0V Logic High, Von/off=14V ALL ALL Von/off to 10%Vo,set Vin,min. to 10%Vo,set 10%Vo,set to 90%Vo,set ALL ALL ALL ALL 3.5 3.5 3.5 130 ms ms ms °C ALL 0.98 M hours ALL 10 grams GENERAL SPECIFICATIONS MTBF Weight Dimensions VPOL16A-12-SIP packages Io=100%of Io.max;Ta=2 5°C 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. 5 of 12 date 11/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP +Vin ON/OFF Control page +Vo 7. Applications 7.1 Layout Design Challenges. Remote ON/OFF In optimizing thermal design the PCB is utilized as a heat sink. Also Q1 VPOL16A-12-SIP some heat is transferred from the VPOL16A-12-SIP module to the main board through connecting pins. The system designer or the end user Common Common must ensure that other components and metal in the vicinity of the VPOL16A-12-SIP series meet the spacing requirements to which the Figure 3. Positive Remote ON/OFF Input Drive Circuit system is approved. Low resistance and low inductance PCB layout traces are the norm and +Vin +Vo Q1 ON/OFF Control 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 VPOL16A-12-SIP as figure 5. Remote ON/OFF 0.29(7.4) Common Common Figure 4. Negative Remote ON/OFF Input Drive Circuit 5.7 UVLO (Under-Voltage Lockout) The voltage on the Vcc pin determines the start of the operation of the LAYOUT PATTERN TOP VIEW All Dimmension In Inches(mm) Tole rance : .XX= ± 0.04 .XXX= ± 0.010 0.33(8.4) 1.1mm PLATED THROUGH HOLE 1.6mm PAD SIZE Figure 5. Recommended VPOL16A-12-SIP Footprint 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. 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 rd 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. 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page 6 of 12 date 11/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP 7.2 Convection Requirements for Cooling To predict the ap proximate cooling needed for the module, refer to the 7.3 Thermal Considerations Power De-rating curves in Figures 8 & 9 . These de-rating curves are The power module operates in a variety of thermal environments; approximations of the ambient temperatures and airflows required to however, sufficient cooling should be provided to help ensure reliable keep the power module temperature below its maximum rating. Once operation of the unit. Heat is removed by conduction, convection, and the module is assembled in the actual system, the module’s radiation to the surrounding environment. The thermal data presented is temperature should be checked as shown in Figure 6 to ensure it does based on measurements taken in a set-up as shown in Figure 6. not exceed 120°C. Figures 8 & 9 represent the test data. Note that the airflow is parallel to Proper cooling can be verified by measuring the power module’s the long axis of the module as shown in Fig 6 for the VPOL16A-12-SIP. temperature at Q1-pin 6 as shown in Figure 7. The temperature at either location should not exceed 120 °C. The output power of the module should not exceed the rated power for the W ind Tunnel module (VO, set x IO, max). The VPOL16A-12-SIP thermal data 25.4(1.0) 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 Bakelite 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. 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. TYPICAL POWER DERATING FOR 5 Vin 3.3 Vout 18 16 Output Current(A) 14 12 10 0LFM 100LFM 200LFM 300LFM 6 4 2 0 0 10 20 30 40 50 60 7 of 12 date 11/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP 8 page 70 80 90 100 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 8 of 12 date 11/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP 7.5 Efficiency vs Load Curves (Fig. 9) VPOL16A-12-SIP Vo=3.3V (Eff Vs Io) VPOL16A-12-SIP Vo=5.0V (Eff Vs Io) 95% 95% 90% 85% 9.0V 12V 14V 80% 75% Efficincy (%) 100% Efficincy (%) 100% 90% 85% 9.0V 12V 14V 80% 75% 70% 70% 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) 5 6 7 8 9 10 11 12 13 14 15 16 Current Load (A) VPOL16A-12-SIP Vo=2.5V (Eff Vs Io) VPOL16A-12-SIP Vo=2.0V (Eff Vs Io) 100% 100% 95% 95% 85% 9.0V 12V 14V 80% 75% 70% Efficincy (%) Efficincy (%) 90% 90% 85% 80% 75% 9.0V 12V 14V 70% 65% 60% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Current Load (A) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Current Load (A) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. VPOL16A-12-SIP Vo=1.8V (Eff Vs Io) date 11/2007 VPOL16A-12-SIP Vo=1.5V (Eff Vs Io) 100% 95% 95% 90% 90% 85% 80% 75% 9.0V 12V 14V 70% 65% Efficincy (%) 100% Efficincy (%) 9 of 12 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP 85% 80% 75% 9.0V 12V 14V 70% 65% 60% 60% 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) 5 6 7 8 9 10 11 12 13 14 15 16 Current Load (A) VPOL16A-12-SIP Vo=1.2V (Eff Vs Io) VPOL16A-12-SIP Vo=0.75V (Eff Vs Io) 100% 100% 95% 95% 90% 85% 80% 75% 9.0V 12V 14V 70% 65% 60% Efficincy (%) 90% Efficincy (%) page 85% 80% 75% 70% 9.0V 12V 14V 65% 60% 55% 50% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Current Load (A) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Current Load (A) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. 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 date 11/2007 VFL is the output voltage at full load VNL is the output voltage at no load The value of line regulation is defined as: inductance should be low. Also, the input capacitors should be placed Line.reg= 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 VLL is the output voltage of minimum input voltage at full load. high capacitance, high ripple rating and low ESR (typical <100mohm). Current Meter A 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. VHL _ VLL x 100% VLL Where: VHL is the output voltage of maximum input voltage at full load. Electrolytic capacitors should be avoided. Circuit as shown in Figure 10 Power Supply +Vin +Sense V 100uF Voltage Meter VPOL16A-12-SIP Common L1 +Vin A +Vo + To Oscilloscope Power 10 of 12 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP 1uH page V Load Common Figure 11. VPOL16A-12-SIP Series Test Setup 7.8 Remote Sense Compensation + 2*100uF Tantalum Supply VPOL16A-12-SIP 220uF ESR<0.1ohm 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 Common 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). Figure 10. Input Reflected-Ripple Test Setup 7.7 Test Set-Up The basic test set-up to measure parameters such as efficiency and 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. load regulation is shown in Figure 11. Things to note are that this When the Remote Sense feature is not being used, leave sense pin converter is non-isolated, as such the input and output share a common disconnected. ground. These grounds should be connected together via low impedance ground plane in the application circuit. When testing a Figure 12. Circuit Configuration for Remote Sense Operation 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 Distribution Losses +Vin Load regulation and line regulation. +Vo +Sense The value of efficiency is defined as: R-Load Vo x Io x 100% ç= Vin x Iin Common Where: Vo is output voltage, Common Distribution Losses Io is output current, Vin is input voltage, Iin is input current. The value of load regulation is defined as: Load .reg= VFL _ VNL x 100% VNL 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page 11 of 12 date 11/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP 7.8 VPOL16A-12-SIP Series Output Voltage Adustment. 7.9 Output Ripple and Noise Measurement The test set-up for noise and ripple measurements is shown in Figure The output Voltage of the VPOL16A-12-SIP can be adjusted in the 14. a coaxial cable with a 50ohm termination was used to prevent range 0.75V to 5.0V by connecting a single resistor on the motherboard impedance mismatch reflections disturbing the noise readings at higher (shown as Rtrim) in Figure 13. When Trim resistor is not connected the frequencies. output voltage defaults to 0.75V +Vin +Vin +Vo +Vo 10uF Tant. VPOL16A-12-SIP 1uF Ceramic R-Load Test Jack Trim R-Load Common VPOL16A-12-SIP Common R trim-up 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. 10500 _ Rtrim = ( _ 1000 ) Vo 0.75 Where: 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 Rtrim-up is the external resistor in ohm, loop stability and bandwidth. V-Infinity’s converters are designed to Vo is the desired output voltage work with load capacitance up-to 8,000uF. It is reco mmended that any To give an exa mple of the above calculation, to set a voltage of 3.3Vdc, additional capacitance, Maximum 8,000uF and low ESR, be connected Rtrim is given by: close to the point of load and outside the remote compensation point. Rtrim = ( 10500 _ 1000 ) _ 3.3 0.75 Rtrim = 3117 ohm 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 REFLOW PROFILE For various output values various resistors are calculated and provided 240 in Table 3 for co nvenience. Rtrim (Kohm) Open 22.33 13.0 9.0 7.4 5.0 3.12 1.47 Table 3 – Trim Resistor Values 200 TEMPERATURE (C) Vo,set (V) 0.75 1.20 1.50 1.80 2.00 2.50 3.30 5.0 160 120 80 40 0 0 30 60 90 120 150 180 210 240 TIME (SECONDS) Figure 15 VPOL16A-12-SIP Reflow Profile 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page 12 of 12 date 11/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL16A-12-SIP 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) 6 7 8 9 10 11 1 2 3 4 5 0.14(3.6) 0.512(13.00) 0.100(2.54) 0.010(0.25) min. 0.025(0.64) 1.000(25.40) 0.050(1.30) 0.28(7.1) 0.025(0.64) 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 0.400(10.20) Figure 19 VPOL16A-12-SIP Mechanical Outline Diagram 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382