rev. PART NUMBER: VPOL10A-12W-SIP page 1 of 13 date 08/2007 DESCRIPTION: point of load converter features * industry standard pin out * high efficiency to 90% * 300 KHz switching frequency * 6.0-14 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 certified * output voltage sequencing (tracking) * power good signal 1. INTRODUCTION 2. VPOL10A-12W-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 5.2 Over-Temperature Protection (OTP) 7.6 Input Capacitance at the Power Module 5.3 Output Voltage Adjustment 7.7 Test Set-Up 5.4 Safe Operating Area (SOA) 7.8 Remote Sense Compensation 5.5 Over Current Protection 7.9 VPOL10A-12W-SIP Series Output Voltage Adustment. 5.6 Remote ON/OFF 7.10 Output Ripple and Noise Measurement 5.7 UVLO (Under-Voltage Lockout) 7.11 Output Capacitance 5.8 Output Voltage Sequencing (Tracking) 8. MECHANICAL OUTLINE DIAGRAMS 8.1 VPOL10A-12W-SIP Mechanical Outline Diagrams 7.5 Efficiency vs Load Curves 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. PART NUMBER: VPOL10A-12W-SIP page 2 of 13 date 08/2007 DESCRIPTION: point of load converter converter is also protected against over-temperature conditions. If the 1. Introduction 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 VPOL10A-12W-SIP series of Non Isolated DC-DC Converters. These L1 Q1 +VIN +VO are highly efficient, reliable and compact, high power density, single output DC/DC converters. These “Point of Load” modules serve the C1 needs specifically of the fixed and mobile telecommunications and Q2 D1 R sense C2 +SENSE computing market, employing economical distributed Power Architectures. The VPOL10A-12W-SIP series provide precisely regulated output voltage range from 0.7525V to 5.0Vdc over a wide COM COM range of input voltage (Vi=6.0 – 14Vdc) and can operate over an ambient temperature range of –40°C to +85°C. Ultra-high efficiency operation is achieved through the use of synchronous rectification and drive control techniques. R1 PGood ON/OFF PWM IC ERR AMP SEQ R trim TRIM R2 The modules are fully protected against short circuit and overtemperature conditions. V-Infinity’s world class automated Figure 1. Electrical Block Diagram manufacturing methods, together with an extensive testing and qualification program, ensure that all VPOL10A-12W-SIP series converters are extremely reliable. 3.2 Thermal Packaging and Physical Design. 2. VPOL10A-12W-SIP Converter Features The VPOL10A-12W-SIP series uses a multi-layer FR4 PCB construction. All surface mount power components are placed on one High efficiency topology, typically 95% at 5.0Vdc side of the PCB, and all low-power control components are placed on Industry standard footprint the other side. Thus, the Heat dissipation of the power components is Wide ambient temperature range, -40C to +85C optimized, ensuring that control components are not thermally stressed. Cost efficient open frame design The converter is an open-frame product and has no case or case pin. Programmable output voltage via external resistor from 0.7525 to The open-frame design has several advantages over encapsulated 5.0Vdc closed devices. Among these advantages are: 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. Output Voltage Sequencing( Tracking ) 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. Power Good Signal (Option) 3. General Description 3.1 Electrical Description A block diagram of the VPOL10A-12W-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 VPOL10A-12W-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 VPOL10A-12W-SIP series converters do not draw any reverse current at start-up. The output voltage can be adjusted from 0.7525 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. The 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page 3 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP 4. Technical Specifications (All specifications are typical at nominal input, full load at 25°C unless otherwise noted.) PARAMETER ABSOLUTE MAXIMUM RATINGS Input Voltage Continuous Operating Temp erature See Thermal Considerations Section NOTES and CONDITIONS Device Min. Typical Max. Units ALL 0 16 Vdc ALL -40 +85 °C ALL -55 +125 °C ALL 6.0 6.5 14 14 Vdc Storage Temperature INPUT CHARACTERISTICS Operating Input Voltage Vo=4.5V Vo=5.0V Input Under-Voltage Lockout Turn-On Voltage Threshold Turn-Off Voltage Threshold Lockout Hysteresis Voltage 12 12 5.0 ALL ALL ALL ALL Vdc Vdc Vdc 4.0 1.0 Maximum Input Current Vin=0 to 14Vdc , Io=Io,max. No-Load Input Current Vo=0.7525V 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 0.4 As 2 Inrush Current (I t) 10 40 40 50 50 60 65 75 95 A mA 2 P-P thru 1uH inductor, 5Hz to 20MHz ALL 200 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 0.7525 5.0 Vdc Io=Io.min to Io.max ALL -0.5 +0.5 % Input Reflected-Ripple Current OUTPUT CHARACTERISTIC Output Voltage Regulation Load Regulation Vin=low line to high line ALL -0.2 +0.2 % Tempera ture Coefficient Line Regulation Ta=-40° C to 85°C ALL -0.03 +0.03 %/ Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth Peak-to-Peak Full Load, 1uF ceramic and 10uF tantalum ALL 75 mV RMS Full Load, 1uF ceramic and 10uF tantalum ALL 30 mV Low ESR ALL 8000 uF External Capacitive Load Operating Output Current Range Output DC Current-Limit Inception Output Voltage =90% Nominal Output Voltage Shout Circuit Protection Continuous with Hiccup Mode Sequency Slew Rate Capability dVSEQ/dt ALL 0 ALL 15 0.1 Sequencing Delay Time 20 10 A 25 A 1.0 10 Tracking Accuracy Power up Power down Power Good Signal Asserted Logic High Vo ALL Suffix “P” V/ms ms 90 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 200 400 mV 110 % rev. page 4 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP Error Brand 50% Step Load Change, di/dt=2.5A/us ALL 200 mV Setting Time (within 1% Vout nominal) 50% Step Load Change, di/dt=2.5A/us ALL 200 us EFFICIENCY 100% Load Vo=0.7525V 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 82 87 89 90 91 92 93 95 % 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 VPOL10A-12W-SIP VPOL10A-12W-SIP KHz 0 0.4 Vin Vdc Vdc 0 2.8 0.4 Vin Vdc Vdc 1 1 mA mA or Open Circuit ON/OFF Control, Negative Logic Remote On/Off Logic Low (Module On) or Open Circuit 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 300 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 3 4 130 ms ms ms ALL 0.92 M hours ALL 8.5 grams GENERAL SPECIFICATIONS MTBF Weight Dimensions Io=100%of Io.max;Ta=2 5°C per MIL-HDBK217F 2x0.51x0.327 inches (50.8x12.95x8.3 mm) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page 5 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP 5. Main Features and Functions removed. The power module will supply up to 150% of rated current. In 5.1 Operating Temperature Range protection. V-Infinity’s VPOL10A-12W-SIP series converters highly efficient 5.6 Remote ON/OFF the event of an over current converter will go into a hiccup mode converter design has resulted in its ability to operate over a wide ambient temperature environment ( -40°C to 85°C). 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 The remote ON/OFF input feature of the converter allows external circuitry to turn the converter ON or OFF. Active-high remote ON/OFF is available as standard. The VPOL10A-12W-SIP are turned on if the remote ON/OFF pin is high(=Vin), or left open. Setting the pin by a number of factors, such as: low(<0.4Vdc) will turn the converter ‘Off’. The signal level of the remote Input voltage range. on/off input is defined with respect to ground. If not using the remote Output load current. Air velocity (forced or natural convection). Mounting orientation of converter PCB with respect to the Airflow. Motherboard PCB design, especially ground and power planes. These can be effective heat sinks for the converter. on/off pin, leave the pin open (module will be on). The part number suffix “N” is Negative remote ON/OFF version. The unit is guaranteed OFF over the full temperature range if this voltage level exceeds 2.8Vdc. The converters are turned on If the on/off pin input is low (<0.4Vdc) or left open. The recommended VPOL10A-12W-SIP remote on/off drive circuit 5.2 Over-Temperature Protection (OTP) as shown as figure 3, 4. The VPOL10A-12W-SIP Series converters are equipped with nonlatching over-temperature protection. A temperature sensor monitors the +Vin temperature of the hot spot (typically, top switch). If the temperature +Vo exceeds a threshold of 130°C (typical) the converter will shut down, disabling the output. When the temperature has decreased the converter will automatically restart. ON/OFF Control Remote ON/OFF Q1 The over-temperature condition can be induced by a variety of reasons VPOL10A-12W-SIP such as external overload condition or a system fan failure. Common 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 Common Figure 3. Positive Remote ON/OFF Input Drive Circuit the range 0.7525 – 5.0Vdc. 5.4 Safe Operating Area (SOA) +Vo +Vin Figure 2 provides a graphical representation of the Safe Operating Area Q1 VPOL10A-12W-SIP (SOA) of the converter. This representation assumes ambient operating conditions such as airflow are met as per thermal guidelines provided in Sections 7.2 and 7.3. ON/OFF Control Remote ON/OFF Vo Common VOLTAGE (V) Vo,nom Common Figure 4. Negative Remote ON/OFF Input Drive Circuit Safe Operating Area Io,max Io,CL Io CURRENT (A) Figure 2. Maximum Output Current Safe Operating Area 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 protection in a fault condition, the unit is equipped with internal overcurrent protection. The unit operates normally once the fault condition is 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. page 6 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP 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 5.0V the converter initiates a soft start. The UVLO function in the converter has a Power start up with SEQ signal Input Voltage=12Vdc Master DC/DC output voltage (CH1) = 5Vdc Salve DC/DC output voltage (CH2)=3.3Vdc Sequencing voltage= 0.6V/msec hysteresis (about 1V) built in to provide noise immunity at start-up. 5.8 Output Voltage Sequencing (Tracking) The VPOL10A-12W-SIP series including a sequencing feature. It is able implement various types of output voltage sequencing in customer applications, VPOL10A-12W-SIP series is accomplishable through an additional sequencing pin. When not using the sequencing feature, tie the SEQ pin to +Vin. When the signal voltage is applied to the SEQ pin, the output voltage tracks this voltage until the output reaches the set point voltage. The SEQ voltage needs to be set higher than the set point of the module. The output voltage will be follow by the voltage on the SEQ pin. On the multiple modules application, we can connect SEQ pin and input signal voltage together to apply on the SEQ pin. Customers can get multiple modules to track their output voltages to follow the voltage of the SEQ pin. To control this module for sequen cing, when the input voltage Figure 6. Example testing circuit of sequencing function applied to the module. The on/off pin is left unconnected so that the module is ON by default. After applying input voltage to the module, a minimum of 10msec delay is required before applying voltage on the SEQ pin and slew rate of the voltage on the SEQ pin see technical Power turn off with SEQ signal voltage Input Voltage=12Vdc (CH1) Master DC/DC output voltage (CH2) = 5Vdc Salve DC/DC output voltage (CH3)=3.3Vdc specifications “ dVSEQ/dt “. After 10msec delay, an Analog voltage is applied to the SEQ pin and the output voltage of the module will track this voltage until output voltage reaches the set point voltage. To initiate simultaneous shutdown of the modules, the SEQ pin voltage is lowered in a controlled manner. Output voltage of the modules track the voltages below their set-point voltage voltages. A valid input voltage must be maintained until the tracking and output voltages reach ground potential to ensure a controlled shutdown of the modules. A typical example testing circuit used master DC/DC converter and SIP Module as shown as below: +Vin Power + C1 +Vo CH1 R1 Load Master DC/DC Converter Supply Common Common Figure 7. Example testing circuit of sequencing function +Vin +Vo SEQ CH2 VPOL10A-12W-SIP Common C2 R2 CH3 Load Common Figure 5. Example testing circuit of sequencing function 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. PART NUMBER: VPOL10A-12W-SIP page 7 of 13 date 08/2007 DESCRIPTION: point of load converter 6. Safety 7. Applications 6.1 Input Fusing and Safety Considerations. 7.1 Layout Design Challenges. Agency Approvals: The power Supply shall be submitted to and receive In optimizing thermal design the PCB is utilized as a heat sink. Also formal approval from the following test agencies. some heat is transferred from the SIP module to the main board through 1.The power supply shall be approved by a nationally recognized testing rd laboratory to UL/CSA 60950 3 Edition (North America) and EN60950 (International) connecting pins. The system designer or the end user must ensure that other components and metal in the vicinity of the VPOL10A-12W-SIP series meet the spacing requirements to which the system is approved. 2. CB Certificate from an internationally recognized test house in Low resistance and low inductance PCB layout traces are the norm and accordance with EN 60950. should be used where possible. Due consideration must also be given to The VPOL10A-12W-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 proper low impedance tracks between power module, input and output grounds. The recommended VPOL10A-12W-SIP footprint as shown as figure 8. with a maximum rating of 20A. 0.29(7.4) LAYOUT PAT TERN TOP VIEW All Dimmension In Inches(mm) Toler ance : .XX=¡ Ó0.02 ( .X=¡ Ó0.5 ) .XXX=¡ Ó0.010 ( .XX=¡ Ó0.25 ) 0.33(8.4) 1.1mm PLATED THROUGH HOLE 1.6mm PAD SIZE Figure 8. Recommended VPOL10A-12W-SIP Footprint 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 12 Output Current(A) 10 8 0LFM 100LFM 4 200LFM 2 300LFM 0 0 10 20 30 40 50 60 8 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP 6 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 9 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP 7.5 Efficiency vs Load Curves VPOL10A-12W-SIP Vo=5.0V (Eff Vs Io) VPOL10A-12W-SIP Vo=3.3V (Eff Vs Io) 95% 95% Efficincy (%) 100% Efficincy (%) 100% 90% 85% 6.5V 12V 14V 80% 75% 90% 85% 6.0V 12V 14V 80% 75% 70% 70% 0 1 2 3 4 5 6 7 8 9 0 10 1 2 3 VPOL10A-12W-SIP Vo=1.8V (Eff Vs Io) 5 6 7 8 9 10 VPOL10A-12W-SIP Vo=2.5V (Eff Vs Io) 100% 100% 95% 95% 90% Efficincy (%) Efficincy (%) 4 Current Load (A) Current Load (A) 90% 85% 80% 85% 6.0V 12V 14V 75% 70% 65% 6.0V 12V 14V 80% 75% 60% 70% 0 1 2 3 4 5 6 Current Load (A) 7 8 9 10 0 1 2 3 4 5 6 Current Load (A) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 7 8 9 10 rev. 10 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP VPOL10A-12W-SIP Vo=1.5V (Eff Vs Io) VPOLW10A-12-SIP Vo=2.0V (Eff Vs Io) 95% 90% 90% Efficincy (%) 95% Efficincy (%) 100% 100% 85% 80% 75% 6.0V 12V 14V 70% 65% 85% 80% 6.0V 12V 14V 75% 70% 65% 60% 60% 0 1 2 3 4 5 6 7 8 9 0 10 1 2 3 4 5 6 7 8 9 10 Current Load (A) Current Load (A) VPOL10A-12W-SIP Vo=1.2V (Eff Vs Io) VPOL10A-12W-SIP Vo=0.75V (Eff Vs Io) 100% 100% 95% 95% 90% 90% 85% Efficincy (%) Efficincy (%) page 85% 80% 80% 75% 75% 70% 6.0V 12V 14V 70% 65% 6.0V 12V 14V 65% 60% 55% 60% 50% 0 1 2 3 4 5 6 Current Load (A) 7 8 9 10 0 1 2 3 4 5 6 Current Load (A) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 7 8 9 10 rev. page 11 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP 7.6 Input Capacitance at the Power Module Line.reg = The VPOL10A-12W-SIP converters must be connected to a low AC source impedance. To avoid problems 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 12 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 x100% 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 Power Supply +Vin A +Vo +Sense + V 100uF VPOL10A-12W-SIP Voltage Meter Common V Load Common Figure 13. VPOL10A-12W-SIP Series Test Setup To Oscilloscope 7.8 Remote Sense Compensation L1 +Vin 1uH Power Supply + 2*100uF Tantalum +Vo R1 VPOL10A-12W-SIP C2 1000uF Electronlyic ESR<0.1ohm Com Load Com Figure 12. 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 13. 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 VPOL10A-12W-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: 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 14). 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. Figure 14. Circuit Configuration for Remote Sense Operation Distribution Losses +Vin +Vo +Sense R-Load VPOL10A-12W-SIP Vo x Io x100% ç= 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: Load .reg = Common Distribution Losses VFL _ VNL x100% VNL Where: VFL is the output voltage at full load VNL is the output voltage at no load The value of line regulation is defined as: 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. 12 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP 7.9 VPOL10A-12W-SIP Series Output Voltage Adustment. The output Voltage of the VPOL10A-12W-SIP can be adjusted in the range 0.7525V to 5.0V by connecting a single resistor on the motherboard (shown as Rtrim) in Figure 15. When Trim resistor is not connected the output voltage defaults to 0.7525V +Vin page COPPER STRIPS VO SCOPE 10uF Power Supply + 100uF ESR<0.1Ohm 1uF LOAD COM VIN VPOL10A-12W-SIP +Vo Trim R-Load VPOL10A-12W-SIP Figure 16. Output Voltage Ripple and Noise Measurement Set-Up R trim-up Common 7.11 Output Capacitance Common Figure 15. Trim-up Voltage Setup The value of Rtrim-up defined as: Rtrim = ( 10500 _ 1000 ) _ Vo 0.7525 Where: Rtri m-up is the external resistor in ohm, Vo is the desired output voltage To gi ve an example of the above calculation, to set a voltage of 3.3Vdc, Rtrim is given by: Rtrim = ( V-Infinity’s VPOL10A-12W-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 i s recommended that any additional capacitance, typically 1,000uF and low ESR (<20mohm), be connected close to the point of load and outside the remote compensation point. 10500 _ 1000 ) _ 3.3 0.7525 Rtrim = 3.122K ohm For various output values various resistors are calculated and provided in Tabl e 3 for convenience. Vo,set (V) 0.7525 1.2 1.5 1.8 2.0 2.5 3.3 5.0 Rtrim (Kohm) Open 22.46 13.05 9.024 7.417 5.009 3.122 1.472 Table 3 – Trim Resistor Values 7.10 Output Ripple and Noise Measurement The test set-up for noise and ripple measurements is shown in Figure 16. a coaxial cable with a 50ohm termination was used to prevent impedance mismatch reflections disturbing the noise readings at higher frequencies. The Output Ripple & Noise is measured with 1uf ceramic and 10uf tantalum. The measured position are 50mm to 75mm(2” to 3”) from the module. 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382 rev. 8. Mechanical Outline Diagrams 8.1 VPOL10A-12W-SIP Mechanical Outline Diagrams Dimensions are in millimeters and inches Tol erance: x.xx ±0.02 in. (0.5mm) , x.xxx ±0.010 in. (0.25 mm) unless otherwise noted SIZE SIP 0.327(8.30)max. 0.23(5.8) 6 7 8 9 10 11 12 1 2 3 4 5 0.14(3.6) 0.510(12.95) 0.100(2.54) 0.025(0.64) 0.010(0.25) min. 0.050(1.30) 0.900(22.90) 0.28(7.1) 0.025(0.64) 0.400(10.20) 0.29(7.4) LAYOUT PATT ERN TOP VIEW All Dimmension In Inches(mm) To lerance : .XX=¡ Ó0.02 ( .X=¡ Ó0.5 ) .XXX=¡ Ó0.010 ( .XX=¡ Ó0.25 ) 13 of 13 date 08/2007 DESCRIPTION: point of load converter PART NUMBER: VPOL10A-12W-SIP 2.00(50.8) page 0.33(8.4) 1.1mm PLATED THROUGH HOLE 1.6mm PAD SIZE PIN CONNECTION Pin FUNCTION +Output 1 +Output 2 3 +Sense +Output 4 5 Common No Pin / PGood 6 Common 7 +V Input 8 +V Input 9 10 Sequency 11 Trim 12 On/Off Control Figure 17 VPOL10A-12W-SIP Mechanical Outline Diagram 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382