rev. PART NUMBER: VPOL5A-5-SIP page 1 of 10 date 08/2007 DESCRIPTION: point of load converter features * high efficiency topology, typically 94% at 3.3 Vdc * 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 3.63 Vdc * 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/EN60950-1 (E222736) certified. 1. INTRODUCTION 2. VPOL5A-5-SIP CONVERTER FEATURES 6. SAFETY 6.1 Input Fusing and Safety Considerations. 3. GENERAL DESCRIPTION 3.1 Electrical Description 7. APPLICATIONS 7.1 Layout Design Challenges. 3.2 Thermal Packaging and Physical Design. 7.2 Convection Requirements for Cooling 4. TECHNICAL SPECIFICATIONS 7.3 Thermal Considerations 5. MAIN FEATURES AND FUNCTIONS 5.1 Operating Temperature Range 7.4 Power De-Rating Curves 7.5 Efficiency vs Load Curves 5.2 Over-Temperature Protection (OTP) 7.6 Input Capacitance at the Power Module 5.3 Output Voltage Adjustment 7.7 Test Set-Up 5.5 Over Current Protection 7.8 VPOL5A-5-SIP Series Output Voltage Adustment. 5.6 Remote on/off 7.9 Output Ripple and Noise Measurement 5.7 UVLO (Under-Voltage Lockout) 7.10 Output Capacitance 8. MECHANICAL OUTLINE DIAGRAMS 8.1 SIP/SMT05 Mechanical Outline Diagrams 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. PART NUMBER: VPOL5A-5-SIP 1. Introduction page 2 of 10 date 08/2007 DESCRIPTION: point of load converter L1 Q1 +VIN This application note describes the features and functions of V-Infinity’s +VO Q2 C1 VPOL5A-5-SIP series of non-isolated dc-dc converters. These are D1 C2 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 COM COM market, employing economical distributed power architectures. The R1 VPOL5A-5-SIP series provide precisely regulated output voltage range from 0.75 V to 3.63 Vdc over a wide range of input voltage (Vi=3.0 – PWM IC ON/OFF 5.5 Vdc) and can operate over an ambient temperature range of –40 to +85 R trim ERR AMP TRIM R2 . Ultra-high efficiency operation is achieved through the use of synchronous rectification and drive control techniques. Figure 1. Electrical Block Diagram 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 3.2 Thermal Packaging and Physical Design. qualification program, ensure that all VPOL5A-5-SIP series converters The VPOL5A-5-SIP series uses a multi-layer FR4 PCB construction. are extremely reliable. All surface mount power components are placed on one side of the PCB, and all low-power control components are placed on the other 2. VPOL5A-5-SIP Converter Features High efficiency topology, typically 94% at 3.3 Vdc Industry standard footprint Wide ambient temperature range, -40C to +85C Cost efficient open frame design 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: Programmable output voltage via external resistor from 0.75 to Efficient Thermal Management: the heat is removed from the 3.63 Vdc heat generating components without heating more sensitive, small No minimum load requirement (Stable at all loads) signal control components. Remote on/off Environmental: Lead free open-frame converters are more easily Remote sense compensation recycled. Fixed switching frequency Cost Efficient: No encapsulation. Cost efficient open-frame Continuous short-circuit protection and over current protection construction. Over-temperature protection (OTP) Reliable: Efficient cooling provided by open frame construction Monotonic startup with pre-bias at the output. offers high reliability and easy diagnostics. UL/IEC/EN60950 Certified. 3. General Description 3.1 Electrical Description A block diagram of the VPOL5A-5-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 VPOL5A-5-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 VPOL5A-5-SIP series converters do not draw any reverse current at start-up. The output voltage can be adjusted from 0.75 to 3.63vdc, 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. The converter is also protected against over-temperature conditions. If the converter is overloaded or the ambient temperature gets too high, the converter will shut down to protect the unit. 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page 3 of 10 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL5A-5-SIP 4. Technical Specifications (All specifications are typical at nominal input, full load at 25 ¢J unless otherwise noted.) PARAMETER ABSOLUTE MAXIMUM RATINGS Input Voltage Continuous Operating Temperature See Thermal Considerations Section NOTES and CONDITIONS Device Min. Typical Max. Units ALL 0 5.8 Vdc ALL -40 +85 ¢J -55 +125 ¢J 5.5 Vdc Storage Temperature ALL INPUT CHARACTERISTICS Vo,set ¡ Vin-0.5 Vdc ALL Maximum Input Current Vin=0 to 5.5 Vdc , Io=Io,max. ALL ALL ALL ALL 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 ALL Off Converter Input Current Shutdown input idle current ALL 10 mA ALL 0.1 As Operating Input Voltage Input Under-Voltage Lockout Turn-On Voltage Threshold Turn-Off Voltage Threshold Lockout Hysteresis Voltage 2 Inrush Current (I t) Input Reflected-Ripple Current 3.0 5 2.0 Vdc Vdc Vdc 1.9 0.1 5 25 30 30 35 35 35 35 A mA 2 P-P thru 1μH inductor, 5Hz to 20MHz ALL 150 mA Output Voltage Set Point Vin=Nominal Vin , Io=Io.max, Tc=25 ¢J ALL -1.5% Vo,set +1.5% Vdc Output Voltage Trim Adjustment Range Selected by an external resistor ALL OUTPUT CHARACTERISTIC 0.75 3.63 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 -0.4 +0.4 % Temperature Coefficient Ta=-40 ¢J to 85 ¢J ALL -0.03 +0.03 %/¢J Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth 50 mV Peak-to-Peak RMS Full Load, 1μF ceramic and 10μF tantalum ALL Full Load, 1μF ceramic and 10μF tantalum ALL 20 mV Low ESR ALL 3000 μF ALL 0 Output DC Current-Limit Inception Output Voltage =90% Nominal Output Voltage ALL 6 Shout Circuit Protection Continuous with Hiccup Mode External Capacitive Load Operating Output Current Range 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 9.5 5 A 15 A rev. 4 of 10 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL5A-5-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 ALL Non-isolation ALL 79 85 87 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) On/Off Control, Negative Logic Remote On/Off 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 ALL Standard Model 300 0 or Open Circuit or Open Circuit KHz 0.4 Vdc Vdc 0.4 Vin Vdc Vdc 1 1 mA mA Vin Suffix “N” Model 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 2 2 4.5 120 ms ms ms ¢J ALL 1.5 M hours ALL 2.3 grams GENERAL SPECIFICATIONS MTBF Weight Dimensions SIP packages SMT packages Io=100%of Io.max;Ta=25 ¢J per MIL-HDBK217F 0.9x0.4x0.22 inches (22.9x10.16x5.6 mm) 0.8x0.45x0.24 inches(20.3x11.43x6.09 mm) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. 5. Main Features and Functions 5.1 Operating Temperature Range V-Infinity’s VPOL5A-5-SIP series converters highly efficient converter design has resulted in its ability to operate over a wide ambient to 85 5 of 10 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL5A-5-SIP temperature environment ( -40 page ). Due consideration must be given to the de-rating curves when ascertaining maximum power that can be drawn from the converter. The maximum power drawn is influenced by a number of factors, such as: 5.5 Over Current Protection All different voltage models have a full continuous short-circuit protection. The unit will auto recover once the short circuit is removed. To provide pr otection in a fault condition, the unit is equipped with internal over-current protection. The unit operates normally once the fault condition is removed. The power module will supply up to 150% of rated current. In the event of an over current converter will go into a hiccup mode protection. 5.6 Remote On/Off Input voltage range. The remote on/off input feature of the converter allows external Output load current. circuitry to turn the converter on or off. Active-high remote on/off is Air velocity (forced or natural convection). Mounting orientation of converter PCB with respect to the Airflow. available as standard. The VPOL5A-5-SIP series converters are turned on if the remote on/off pin is high, or left open or floating. Setting the Motherboard PCB design, especially ground and power planes. pin low will turn the converter off. The signal level of the remote on/off These can be effective heat sinks for the converter. input is defined with respect to ground. If not using the remote on/off 5.2 Over-Temperature Protection (OTP) pin, leave the pin open (module will be on). The part number suffix “N” The VPOL5A-5-SIP Series converters are equipped with non-latching is Negative remote on/off version. The unit is guaranteed off over the over-temperature protection. A te mperature sensor monitors the full temperature range if this voltage level exceeds 2.8 Vdc. The temperature of the hot spot (typically, top switch). If the temperature converters are turned on If the on/off pin input is low or left open. The exceeds a threshold of 120 C (typical) the converter will shut down, recommended SIP remote on/off drive circuit as shown as figure 3, 4. disabling the output. When the temperature has decreased the converter will automatically restart. The over-temperature condition can be induced by a variety of reasons such as external overload condition or a system fan failure. +Vin +Vo 5.3 Output Voltage Adjustment Section 7.8 describes in detail as to how to trim the output voltage with respect to its set point. The output voltage on all models is trimmable in the range 0.75 – 3.63 Vdc. On/Off Control Remote On/Off Q1 SIP Series 5.4 Safe Operating Area (SOA) Figure 2 provides a graphical representation of the Safe Operating Common Area (SOA) of the converter. This representation assumes ambient operating conditions such as airflow are met as per thermal guidelines Common Figure 3. Positive Remote on/off Input Drive Circuit provided in Sections 7.2 and 7.3. Vo +Vin Q1 Vo,nom VOLTAGE (V) +Vo SIP Series On/Off Control Safe Operating Area Remote On/Off Common Common Figure 4. Negative Remote On/Off Input Drive Circuit Io,max Io,CL Io CURRENT (A) Figure 2. Maximum Output Current Safe Operating Area 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 2.0 V the converter initiates a soft start. The UVLO function in the converter has a hysterosis (about 100mV) built in to provide noise immunity at startup. 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page 6 of 10 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL5A-5-SIP 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. W ind Tunnel 25.4(1.0) Bakelite 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) Power Module 2. CB Certificate from an internationally recognized test house in accordance with EN 60950. The VPOL5A-5-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 76.2(3.0) with a maximum rating of 10 A. 7. Applications Thermocuple Location for measuring ambient temperature and airflow 7.1 Layout Design Challenges. In optimizing thermal design the PCB is utilized as a heat sink. Also some heat is transferred from the SIP module to the main board 12.7(0.5) through connecting pins. The system designer or the end user must ensure that other components and metal in the vicinity of the VPOL5A-5-SIP series meet the spacing requirements to which the Air flow 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 SIP footprint as shown in figure 5. Note : Dimensions are in millimeters and (inches) Figure 6. Thermal Test Setup 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 1.1mm PLATED THROUGH HOLE 1.6mm PAD SIZE 0.20(5.1) LAYOUT PA TTERN TOP VIEW 0.24(6.1) All Dimmension In Inches(mm) Tolerance : .XX= ±0.02 ( ± 0.5 ) .XXX= ±0.010 ( ± 0.25 ) Figure 5. Recommended SIP Footprint 7.2 Convection Requirements for Cooling radiation to the surrounding environment. The thermal data presented is based on measurements taken in a set-up as shown in Figure7. Figures 8 and 9 represent the test data. Note that the airflow is parallel to the long axis of the module as shown in Figure7 for the VPOL5A-5-SIP. The temperature at either location should not exceed 110 °C. The output power of the module should not exceed the rated power for the module (VO, set x IO, max). 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 Fig7. To predict the ap proximate cooling needed for the module, refer to the Power De-rating curves in Figures 10 to 13. These derating 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 110°C. Proper cooling can be verified by measuring the power module’s temperature at Q1-pin 6 as shown in Figure 6. Figure 7. Temperature Measurement Location for SIP 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. TYPICAL POWER DERATING FOR 5Vin 3.3Vout 6.0 Output Current(A) 5.0 4.0 0LFM 100LFM 2.0 200LFM 1.0 0.0 0 10 20 30 40 50 7 of 10 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL5A-5-SIP 3.0 page 60 70 80 90 100 o Ambient Temperature( C) Figure 2. Typical Power De-rating for 5V IN 3.3Vout 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 10 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL5A-5-SIP 7.5 Efficiency vs Load Curves VPOL5A-5-SIP Vo=3.3V (Eff Vs Io) VPOL5A-5-SIP Vo=2.5V (Eff Vs Io) 95% 95% Efficincy (%) 100% Efficincy (%) 100% 90% 85% 4.5V 5.0V 5.5V 80% 75% 90% 85% 3.0V 5.0V 5.5V 80% 75% 70% 70% 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 0.5 1 Current Load (A) 95% 95% Efficincy (%) 100% Efficincy (%) 2.5 3 3.5 4 4.5 5 VPOL5A-5-SIP Vo=1.5V (Eff Vs Io) VPOL5A-5-SIP Vo=1.8V (Eff Vs Io) 90% 85% 3.0V 5.0V 5.5V 75% 2 Current Load (A) 100% 80% 1.5 90% 85% 3.0V 5.0V 5.5V 80% 75% 70% 70% 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 0.5 1 Current Load (A) 1.5 2 2.5 3 3.5 4 4.5 5 Current Load (A) VPOL5A-5-SIP Vo=1.2V (Eff Vs Io) VPOL5A-5-SIP Vo=0.75V (Eff Vs Io) 100% 100% 95% 95% Efficincy (%) Efficincy (%) 90% 90% 85% 3.0V 5.0V 5.5V 80% 75% 85% 80% 75% 3.0V 5.0V 5.5V 70% 65% 70% 60% 0 0.5 1 1.5 2 2.5 3 3.5 Current Load (A) 4 4.5 5 0 0.5 1 1.5 2 2.5 3 3.5 Current Load (A) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 4 4.5 5 rev. The SIP converters must be connected to a low ac source impedance. To avoid proble ms with loop stability source inductance should be low. Line.reg 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 VLL is the output voltage of minimum input voltage at full load. be avoided. Circuit as shown in Figure 10 represents typical Current Meter measurement methods for ripple current. Input reflected-ripple current A is measured with a simulated source Inductance of 1μH. Current is Power measured at the input of the module. Supply +Vin L1 +Vin + V 100uF Voltage Meter VPOL5A-5-SIP Series VPOL5A-5-SIP Common Figure 10. Input Reflected-Ripple Test Setup 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 VInfinity’s VPOL5A-5-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: Vo x Io x 100% Vin x Iin 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: Load .reg = V Common Figure 11. VPOL5A-5-SIP Series Test Setup 220uF ESR<0.1ohm ç= A +Vo +Sense Common To Oscilloscope Supply VHL _ VLL x 100% VLL Where: VHL is the output voltage of maximum input voltage at full load. rating and low ESR (typical <100mohm). Electrolytic capacitors should 2*100uF Tantalum 08/2007 The value of line regulation is defined as: Also, the input capacitors should be placed close to the converter input + date VNL is the output voltage at no load 7.6 Input Capacitance at the Power Module Power 9 of 10 DESCRIPTION: point of load converter PART NUMBER: VPOL5A-5-SIP 1uH page VFL _ VNL x 100% VNL 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 Load rev. page 10 of 10 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL5A-5-SIP 7.8 VPOL5A-5-SIP Series Output Voltage Adustment. 7.9 Output Ripple and Noise Measurement The output Voltage of the VPOL5A-5-SIPS33A can be adjusted in the The test set-up for noise and ripple measurements is shown in Figure range 0.75V to 3.63V by connecting a single resistor on the 18. a coaxial cable with a 50ohm termination was used to prevent motherboard (shown as Rtrim) in Figure 12v. When Trim resistor is not impedance mismatch reflections disturbing the noise readings at connected the output voltage defaults to 0.75V higher frequencies5^ +Vin +Vin +Vo 10uF Tant. VPOL5A-5-SIP Trim 1uF Ceramic R-Load VPOL5A-5-SIP Common R-Load Test Jack Common R trim-up Common +Vo Common Figure 13. Output Voltage Ripple and Noise Measurement Set-Up Figure 12. Trim-up Voltage Setup 7.10 Output Capacitance V-Infinity’s VPOL5A-5-SIP series converters provide unconditional The value of Rtrim-up defined as: stability with or without external capacitors. For good transient 21070 _ Rtrim = ( _ 5110 ) Vo 0.75 Where: 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 Rtrim-up is the external resistor in ohm, considerations for low resistance and low inductance tracks. Vo is the desired output voltage Output capacitors with its associated ESR values have an impact on To give an exa mple of the above calculation, to set a voltage of 3.3 loop stability and bandwidth. V-Infinity’s converters are designed to Vdc, Rtrim is given by: work with load capacitance up-to 3,000 μF. It is rec ommended that any additional capacitance, Maximum 3,000 μF and low ESR, be Rtrim = ( 21070 _ 5110 ) Vo _ 0.75 Rtrim = 3153 ohm connected close to the point of load and outside the remote compensation point. 8. Mechanical Outline Diagrams For various output values various resistors are calculated and provided in Table 3 for co nvenience. Vo,set (V) 0.75 1.20 1.50 1.80 2.00 2.50 3.30 3.63 8.1 SIP/SMT05 Mechanical Outline Diagrams Dimensions are in millimeters and inches Rtrim (Kohm) Open 41.71 22.98 14.96 11.75 6.93 3.15 2.20 Table 3 – Trim Resistor Values Tolerance: x.xx ±0.02 in. (0.5mm) , x.xxx ±0.010 in. (0.25 mm) unless otherwise noted SIZE SIP05 0.90(22.9) PIN CONNECTION 0.22(5.6)Max. Pin 1 2 3 4 5 0.400(10.16) 0.14(3.6) 0.025(0.64) 0.100(2.54) 0.200(5.08) 0.700(17.78) 0.025(0.64) FUNCTION 1 +Output 2 Trim 3 Common 4 +V Input 5 On/Off 0.19(4.7) 0.800(20.32) Figure 14 VPOL5A-5-SIP Mechanical Outline Diagram 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382