Application Information MPM Series DC-to-DC Converter Modules General Description The MPM (Micro Power Module) series is a hybrid IC which incorporates a non-isolated buck DC-to-DC converter circuit with an inductor in a single fully molded package. The IC enables designing a power supply circuit with fewer external components. It is ideal for the replacement of a discrete DC-to-DC converter IC, such as a local regulator on various systems, to lower component count, and to save space. Features and Benefits • • • • • • Fewer external components required: IC operates just by connecting an input smoothing capacitor, an output smoothing capacitor, and output voltage setup resistance. Built-in inductor: Built-in power inductor eliminates requirement to evaluate and select the inductor separately. Sanken proprietary fully molded and integrated package: The full-mold package allows a screw clamp connection to a heatsink. Depending on an output voltage setup and load conditions, the IC can be operated without a heatsink. Wide input voltage range, high efficiency: Input voltage range of 9 VDC to output of 16 to 40 V. When VO = 12 V at 3 A, the efficiency is 91% (typ). Various protection functions: Protection functions such as Overcurrent protection (OCP), Overvoltage protection (OVP) and Thermal Shutdown (TSD) are built-in. Built-in phase compensation: Eliminates the requirement for an external constant clock; the reference voltage of the IC output has 0.5 V ±2% accuracy, and is a control drive type phase compensation. MPM-AN January 31, 2013 Figure 1. MPM series packages are fully molded DIPs (3GR-S package) with a tab for external heatsink screw clamp mounting. The product lineup for the MPM series provides the following options: Input Voltage (VDC) Output Voltage (VDC) MPM01 9 to 40 1.8 to 12 3 250 MPM04 16 to 40 12 to 24 3 250 Part Number SANKEN ELECTRIC CO., LTD. http://www.sanken-ele.co.jp/en/ Output Current (A) Drive Frequency (kHz) March 2012 Functional Block Diagram 8,9 MPM SW VIN SVIN BS SW High-side MOSFET EN_SS MIC FSET Built-in coil VO FB R3 AGND COMP PGND LS_GATE Low-side MOSFET VIN 2 GND FB OUT 1,3 4 5,6,7 RFB CIN Pin-out Diagram GND GND OUT GND 4 2 VIN Input power pin 3 GND Ground pin 4 FB 5, 6, 7 OUT Output pin 8, 9 SW Oscillation frequency measuring pin 6 7 SW SW Name 1 5 OUT OUT Number 3 FB 8 9 Pin List Table 2 1 VIN CO Function Ground Feedback pin, and connection pin for resistor RFB for output voltage setup Table of Contents Package Diagram Electrical Characteristics Temperature Derating Curves Application Information Typical Application Circuits Setting Output Voltage Minimum Input/Output Voltage Difference Choosing the Input-Smoothing Capacitance, CIN Choosing the Output-Smoothing Capacitance, CO Evaluation Board for MPM0x Series Static Performance Characteristics Estimated Lift Characteristics Temperature Difference versus Acceleration Factor MPM-AN SANKEN ELECTRIC CO., LTD. 3 4 6 7 7 8 8 9 11 12 13 14 15 March 2012 2 Package Diagram 3GR-S package 15.5 ±0.2 3 Gate protrusion 5 ±0.2 23 ±0.3 5 ±0.2 Ø3.2 ±0.2 A 3.3 ±0.1 (At roots of pins) (7) R-End R-End +0.2 1.35 – 0.1 +0.2 0.85 – 0.1 +0.2 0.65 – 0.1 3.1 ±0.5 +0.2 2.15 – 0.1 2 - (R1.3) 10.1 ±0.5 3.3 3.3 ±0.5 B 4.5 ±0.7 (At tips of pins) 8xP2.54±0.1 = (20.32) (At roots of pins) 24.2±0.2 Case centerline Branding Line A: MPMxx Line B: Lot number Pin centerline 0.4 Leadform: LF971 Pin material: Cu Pin coating: Nickle and solder dip Weight: Approximately 20 g Screw clamp bolting torque: 0.588 to 0.785 N • m 0.7 1 2 3 4 5 6 7 8 9 0.7 Front View Pb-free. Device composition compliant with the RoHS directive. MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 3 Electrical Characteristics • This section provides electrical characteristic data for each product. • The polarity value for current specifies a sink as "+ ," and a source as “−,” referencing the IC. • Please refer to the datasheet of each product for additional details. Absolute Maximum Ratings Characteristic Symbol Notes Rating Unit V VIN Pin Voltage VIN –0.3 to 41 FB Pin Voltage VFB –0.3 to 6 V MPM01 –0.3 to 13 V MPM04 –0.3 to 28.8 V 55 V –20 to 150 °C Tstg –20 to 120 °C RθJ-F 7.7 °C/W VO Pin Voltage Voltage Between VIN and SW Pins Operating Ambient Temperature Storage Temperature Thermal Resistance (MIC to leadframe) VO VVIN-SW Limited due to the overtemperature protection; overtemperature protection detection temperature is about 160°C Tj . Recommended Operating Conditions1 Characteristic Symbol Input Voltage Range2 VIN Output Current Range3 IO Operating Junction Temperature TJOP Operating Ambient Temperature3 TA Test Conditions Min. Max. Unit MPM01 9 40 V MPM04 16 40 V 0 3 A –20 125 °C –20 85 °C With derating 1A recommended operating conditions is an operating condition required in order to maintain the normal circuit functions shown in the Electrical Characteristics table, and it is necessary to remain within the condition in actual use. 2Depending on the setup of the output voltage, V , V (min) < V condition may occur. Because this product is not a boost regulator, O IN O VIN > VO shall be a condition of operation. Please refer to the Minimum Input/Output Voltage Difference section. 3However, it is necessary to use it within a derating curve. Please refer to Temperature Derating curves. MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 4 Electrical Characteristics1 Unless specifically noted, TA is 25°C Characteristic Symbol Reference Voltage VFB(REF) Test Conditions VIN = 33 V, set on IO = 1 A Min. Typ. Max. Unit 0.490 0.500 0.510 V Efficiency2 η VIN = 33 V, VO = 12 V, set on IO = 3 A – 91 – % SW Frequency fO VIN = 33 V, VO = 12 V, set on IO = 3 A 212 250 288 kHz Line Regulation3 VLINE Input VIN = 16 to 40 V, set on VO = 12 V, IO = 1 A – – ±2 % Load Regulation3 VLOAD VIN = 33 V, VO = 12 V, set on IO = 0 to 3 A – – ±3 % 3.2 5.60 7 A – 12 – mA 151 160 – °C – 7.3 8.0 V – 50 – ms Over Current Protection Starting Current4 IS Set VIN = 33 V, VO = 12 V, auto restart / voltage drooping over current protection Input Circuit Current IIN VIN = 33 V, IO = 0 A, VFB = 1 V MIC Thermal Protection Start-up Temperature5 TJ Input VIN = 16 to 40 V Supply Voltage Undervoltage Protection VUVLO Start-up Delay Time tSTART 1Values VIN =16 to 40 V, start-up to VO reaching the target voltage level apply when the device is configured as shown in the Standard Connection Diagram. is calculated by the following formula: 2Efficiency η (%) = VO × IO VIN × IIN × 100 (1) 3The value for VO cited here is nominal, and does not take take into consideration variance of the external resistor RFB (VO is set by RFB, please refer to the Application section for details). To determine the actual load regulation, the user must check the variance of RFB in the application. 4Because the inductance of the built-in coil and the frequency of output are constant, the OCP operating point may vary when V is not 12 V. In using O the device at a VO other than 12 V, the user must check the actual OCP operating point in the application. 5Thermal protection has automatic restart. MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 5 Temperature Derating Curves 3.5 3.0 VO = 12 V, VIN = 33 V VO = 15 V, VIN = 33 V IO (A) 2.5 2.0 VO = 18 V, VIN = 33 V 1.5 VO = 20 V, VIN = 33 V 1.0 VO = 24 V, VIN = 36 V 0.5 0 -20 -10 0 10 20 30 40 50 60 70 80 90 100 TA (°C) Figure 2a. Ambient Temperature versus Output Current Derating (1), VIN = 33 V or 36 V 3.5 3.0 VO = 5 V, VIN = 24 V IO (A) 2.5 VO = 12 V/15 V, VIN = 24 V 2.0 1.5 VO = 18 V, VIN = 24 V 1.0 0.5 0 -20 -10 0 10 20 30 40 50 60 70 80 90 100 TA (°C) Figure 2b. Ambient Temperature versus Output Current Derating (2), VIN = 24 V Note 1: Traces for VO = 5 to 12 V indicate MPM01 performance, traces for VO = 15 to 24 V indicate MPM04. Note 2: Graphs are under these conditions: without heat sink and air cooling without fan. (Screw clamp heatsink mounting is an option for the application.) Note 3: To estimate performance for VO = 2.5 V and 3.3 V, please use the trace for VO = 5 V, as shown in figure 4. MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 6 Application Information Typical Application Circuits 8 9 SW SW MPM Series 2 VIN GND GND 1 C1 5 6 7 OUT OUT OUT FB 3 C2 4 C3 Load RFB • Pins 8 and 9 (SW) are test-only terminals for measuring oscillating frequency. Please leave open for normal operation. • C1, C2, C3 recommended values switching mode power supply applications, not for general electronic circuits: ▫ C1: 50 V / 1000 μF ▫ C2, C3: 25 V / 1000 μF × 2 units • RFB is the resistance for setting output voltage. Refer to the Setting Output Voltage section. Figure 3. Standard connection diagram RFB MPM0x 2 1 4 3 6 5 8 7 9 (Top View) – VIN + GND – CIN + CO (C2) OUT CO (C3) • It is recommended that the traces between the negative side of the output capacitors (CO) and the GND pins (1 and 3), be as short as possible in order to minimize the impedance of the loop, including the IC internal circuit. • Pins 8 and 9 (SW) are test-only terminals for measuring oscillating frequency. Please leave open for normal operation. The pins should be mounted only on isolated lands, and should not connect with traces of other potentials. That might cause a failure. • Please place RFB as near the IC as possible, with the shortest trace length. The circuit may malfunction if the RFB trace is too long. GND Figure 4. Recommended board layout MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 7 Setting Output Voltage Output voltage is set by the value selected for RFB (see figure 7), according to the following formula: VO = VFB 1 + R3 RFB (2) table, VIN must, however, be within the specified maximum and the minimum values range. For example, although for MPM01, at VO =2.5 V the recommended the minimum input-and-output voltage difference is 6.5 V (VIN ≥ 2.5 V + 4 V), keep in mind that the Recommended Operating Condition is VIN ≥ 9 V minimum. Figure 8 shows the value of VO for various RFB values. The limit at VO = 12 V applies to the MPM01, which has an Absolute Maximum Rating of 13 V. The MPM series has fixed frequency and inductance. In the case where the duty cycle exceeds 50%, there is a concern about the occurrence of subharmonic oscillation. To ensure proper operation of the device, please refer to the input / output conditions listed in the table 1 and check the operation of the device with recommended input / output voltage ratings in the application. Minimum Input/Output Voltage Difference Table 1 shows the recommended value of the required input voltage, VIN , to provide a specific VO value. Although the VIN recommended value is shown as greater than the value in the Although for the MPM04 a VIN more than 36 V is recommended for VO = 24 V, because that would provide only a small margin below the recommended maximum 40 V, the power supply voltage should be stabilized before being applied to the MPM04. RFB for output voltage VO = 5 V can be calculated as 500 Ω, and for VO =12 V as 200 Ω (typical value). L1 9.1 μH ±20% R3 4.6 kΩ ±1% MIC – MPM 5,6,7 OUT 4 FB + Table 1. Input/Output Differences VFB = 0.5 V ±2% Output Voltage,VO External RFB Output Voltage,VO Setting Resistor Part Number VIN Voltage (V) VO Setting (V) Input Voltage Recommended Value MPM01 9 to 40 1.8 to 12 VIN ≥ VO + 4 V MPM04 16 to 40 12 to 18 VIN ≥ VO + 4 V 20 30 V ≤ VIN ≤ 40 V 24 36 V ≤ VIN ≤ 40 V VO (V) Figure 7. RFB placement for output voltage setting 26 24 22 20 18 16 14 12 10 8 6 4 2 0 MPM01 Typical VO Value 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 RFB (Ω) Figure 8. MPM04 RFB constant versus output voltage Vo setting curve MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 8 Choosing the Input-Smoothing Capacitance, CIN For both the MPM01 and MPM04, there are three conditions that must be taken into consideration for calculating a value for the input smoothing capacitor CIN : supply ripple current, supply ripple voltage, and rated voltage of the capacitor, described as follows. where L indicates the inductance of the IC built-in coil, and tON indicates the on-time. 1. Determine Supply Ripple Current Conditions Assuming zero impedance between the power supply and VIN, the power supply would provide 100% of power to the VIN terminal and no ripple current would flow to the smoothing capacitor. But in the actual circuit, power supplied from the supply source will vary due to impedance. When specifying the capacitor rating, this case assumes that the smoothing capacitor supplies full power to VIN, as a worst case. • Ripple current valley equation For the following discussion, refer to figures 9 and 10 for a typical input capacitor circuit and circuit current behavior. Given: ICIN(av) = IO × D (3) where D indicates the capacitor duty cycle (ratio of tON to tOFF), and IO indicates the load current. ∆IL = ( VIN – VO ) × tON L • Ripple current peak equation ILp' = IO + ILv' = IO – ∆IL 2 ∆IL 2 – ICIN(av) (5) – ICIN(av) (6) Because the ripple current of the capacitor is an AC waveform, it is calculated as the square root of the sum of the squares of the discharge and charge ripple currents: • Ripple current during discharging equation ICINRIPPLE(DIS) = tON × [I 2Lp' + (ILp' × ILv' ) + I 2Lv' ] 3×T (7) where T indicates the period of the combined charge-discharge cycle. • Ripple current during charging equation ICINRIPPLE(CHG) = (4) (8) (1 – D) × I 2CIN(av) • Combined ripple current equation for input smoothing capacitor MPM0x VIN GND Charge (tOFF) ICINRIPPLE = I 2CINRIPPLE(DIS) + I 2CINRIPPLE(CHG) (9) Example Discharge (tON) Given: VIN = 24 V , VO = 12 V, IO = 3 A , charge-discharge cycle frequency = 250 kHz, T = 4 μs, D for VO / VIN = 0.5, tON = 2 μs, inductance of IC built-in inductor = 9.1 μH. Substituting into equation 3: ICIN(av) = 3 (A) × 0.5 = 1.5 A Figure 9. Charge/discharge of an input capacitor Substituting into equation 4: ILp' ∆IL = ∆IL (24 (V) – 12 (V)) × 2 (μs) = 2.637 A 9.1 (μs) Substituting into equation 5: IO CIN discharging ILp' = 3 (A) + 2.637 (A) 2 – 1.5 (A) = 2.8185 (A) Substituting into equation 6: ILv ' ICIN(av), 0 CIN charging tON ILv' = 3 (A) – 2.637 (A) 2 – 1.5 (A) = 0.8185 (A) Figure 10. The ripple current model of an input capacitor MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 9 From the calculated ILp' and ILv' , ICINRIPPLE(DIS) can be calculated by substituting into equation 7: ICINRIPPLE(DIS) = 2 (μs) × [2.81852 (A) + (2.8185 (A) × 0.1815 (A)) + 0.18152 (A) ] 3 × 4 (μs) = 1.1894 (A) Also, ICINRIPPLE(CHG) will be can be calculated by substituting into equation 8: voltage on a 24 VAC / 50 kHz voltage waveform. To estimate the valley point of the ripple voltage that arises when the smoothing capacitor is discharging to load from a VIN with a peak 24 VACrms, the direct voltage should be doubled to approximately 33 V, with a margin of –20%, or 6.6 V from the valley point. Although the 20% margin is optional, and the greater the value, the lower the circuit capacity, please keep in mind that a large utility mains frequency component will also be passed through as ripple on the output voltage, VO . CIN can be calculated as follows: ICINRIPPLE(CHG) = (1 – 0.5) × 1.52 (A) = 1.0606 (A) CIN ≈ Therefore, the input smoothing capacitor combined ripple current ICINRIPPLE(DIS) can be calculated by substituting into equation 9: ICINRIPPLE = 1.1894 (A) + 1.0606 (A) = 1.594 (Arms) It is required to select an input smoothing capacitor which can support the above-calculated ripple current. Please refer to a capacitor manufacturer catalog in order to select a capacitor rated for this ripple current. 2. Determine Supply Ripple Voltage Conditions This case explains how to determine ripple voltage, ∆VIN , for 24 VAC / 50 Hz input. Refer to figure 11, which shows the ripple IO × D × (1 – D) fr × ∆VIN (10) If D is the duty cycle, with VIN = 33 V and VO = 12 V, D = 12 V / 33 V = 0.3636. Substituting into equation 10: CIN ≈ 3 (A) × 0.3636 × (1 – 0.3636) ≈ 1051 (μF) 100 (Hz) × 6.6 (V) (10) A capacitance of 1051 μF or more is required for the smoothing capacitor, CIN. Thus, when bridge-rectifying 24 VAC, the required capacitance of the smoothing capacitor changes considerably according to the valley point of of the voltage ripple of the utility mains. Peak = 33 V ΔVIN Valley = 26.4 V 0V Figure 11. VIN ripple voltage resulting from smoothing the full wave rectification of utility mains frequency with a CIN of 1000 μF and a load after smoothing of 33 W. Blue trace is VIN ripple (10 V / div.), red is VIN 24VAC, 50 Hz (10 V / div), time is 4.8 ms / div. MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 10 In the case where a user has a stable 24 VDC supply voltage, it is not required to have a 1051 μF capacitor. But we recommend having a capacitor which can supply at least ICINRIPPLE (obtained from equation 9). Because CIN has a role in avoiding operating failure, please do not use the device without CIN . 3. Rated Voltage of the Capacitor Assuming full wave rectification of the 24 VAC supply, because there is no margin, the impedance beyond 50 V should be calculated at a 35 V impedance. In summary, the value for the input smoothing capacitor, CIN , should be determined by considering the following conditions: • The capacitor, CIN, shall have sufficient ripple current calculated by the formulas • When the device is used at 24 VAC / 50 Hz as introduced as a case, a user should consider the valley point of the ripple voltage and choose a capacitor which can match the voltage • A sufficiently high impedance that can provide an adequate margin, rather than one based on just the maximum VIN The selected capacitor should be from a series specified for switching mode power supply use in the capacitor manufacturer catalog. VRIPPLE = 2.637 (A)× 20 (mΩ) = 52.7 (mVpp) In order to calculate the ESR based on a ripple voltage of 100 mVpp , rearrange equation 11: ESR = VRIPPLE / ΔIL Substituting into equation 12 : ESR = 100 (mV) / 2.637(A) = 37.92 (mΩ) This, it is required to have electrolytic capacitance connected which has the ESR characteristic not more than 37.9 mΩ at room temperature. 2. Determine Output Ripple Current Conditions Next, the ripple current which flows into the output smoothing capacitance, CO , is given by the equation 13, ICO(RIPPLE) , providing a practical means of calculating the critical current, ΔIL of the inductor: ICO(RIPPLE) = ΔIL / (2√−3 ) (13) Example Given: VIN = 24 V , VO = 12 V, IO = 3 A , charge-discharge cycle frequency = 250 kHz, T = 4 μs, D for VO / VIN = 0.5, tON = 2 μs, inductance of IC built-in inductor = 9.1 μH. Choosing the Output-Smoothing Capacitance, CO Neither the MPM01 nor the MPM04 have a built-in output smoothing capacitor. The user should evaluate the application requirements and mounting conditions to select and place an external output smoothing capacitor. Example 0.1 –55°C –25°C 0.01 –20°C 85°C 0.001 Given: VIN = 24 V , VO = 12 V, IO = 3 A , charge-discharge cycle frequency = 250 kHz, T = 4 μs, D for VO / VIN = 0.5, tON = 2 μs, inductance of IC built-in inductor = 9.1 μH. At room temperature conditions (see figure 12), assume ESR temporarily set to 20 mΩ, and ΔIL = 2.637 A from equation 4, substituting into equation 11: MPM-AN 1 Impendance (Ω) 1. Determine Output Ripple Current Conditions Output ripple voltage is determined by the critical current, ∆IL , of the inductor, and the ESR (Equivalent Series Resistance), which is a characteristic of the capacitor. Thus, ripple can be obtained by the following formula: VRIPPLE = ΔIL × ESR (11) Using ΔIL = 2.637 A from equation 4, and multiplying that value with the ESR of the smoothing capacitor, the output ripple voltage can be calculated. (12) 0.1 1 10 100 1000 Frequency (kHz) Figure 12. Temperature characteristics of aluminum electrolytic capacitor impedance SANKEN ELECTRIC CO., LTD. March 2012 11 Calculate by substituting into equation 4. ∆IL = ( 24 (V) – 12 (V ) × 2 ) = 2.637 (A) 9.1 (μH) Substituting into equation 13: ICO(RIPPLE) = 2.637 (A) / (2√− 3 ) = 0.761 (Arms) The selected capacitor should be specified with sufficient margin above 0.761 (Arms) in the capacitor manufacturer catalog. 3. Determine Breakdown Voltage Although in the above example, VO = 12 V, it is recommended that the output smoothing capacitor be rated for more than 16 V breakdown voltage In summary, the value for the output smoothing capacitance, CO , should be determined by considering the following conditions: • the allowable ripple current performance that can provide a margin beyond the calculated ripple current • the ESR characteristic during the room temperature conditions is determined by what output ripple voltage is set, which must balance with the power supply specification of the load circuit • a sufficiently high impedance that can provide an adequate margin, rather than one base on just the maximum VO The selected capacitor should be from a series specified for switching mode power supply use in the capacitor manufacturer catalog. Table 2. Evaluation Board Parts List (Valid at VIN = 33 V, VO = 5 V) Symbol Part Type Description Manufacturer C1 Aluminum electrolytic capacitor ZLH, 50 V / 1000 μF Rubycon C2 Aluminum electrolytic capacitor YXG, 25 V / 680 μF Rubycon C3 Aluminum electrolytic capacitor LXZ, 25 V / 470 μF Chemi-con CN1, CN2 Connector B2P3-VH JST IC1 DC/DC module MPM01 Sanken JP1 Jumper wire Ø0.5 mm, Sn Plated – PCB Printed circuit board One side of CEM3 – R1 Carbon resistance R2 Carbon resistance 1/ 4 W, 510 Ω – Open – Evaluation Board for MPM0x Series The MPM0x evaluation board can be used for experimental use for evaluation of MPM series. It is shown in figure 13, along with the corresponding circuit schematic. The parts list for the board is provided in table 2. The parts listed are for a reference only, and should be replaced with application standard parts prior to performing each experiment. CO VIN(+) GND1 CN1 1 2 VIN GND GND 3 1 C1 (CIN) OUT 5 OUT 6 OUT FB SW SW 7 IC1 (MPM01) 3 R1 (RFB) R2 (RFB) CN2 3 CIN Output GND VO(+) + 1 Input GND GND1 8 9 (Open) C2 (CO) C3 (CO) + JP1 MPM01 RFB Figure 13. Evaluation board circuit diagram and photograph MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 12 Static Performance Characteristics Test measurements for the MPM01 and MPM04 are provided in this section. These are typical values taken in our measurement environment, for reference. 100 MPM04: VO = 18 V, VIN = 24 V MPM04: VO = 24 V, VIN = 36 V η (%) 95 90 MPM01: VO = 12 V, VIN = 24 V 85 MPM01: VO = 5 V, VIN = 24 V 80 MPM01: VO = 3.3 V, VIN = 12 V 75 70 0 0.5 1 1.5 2 2.5 3 2.5 3 IO (A) VO (V) Figure 14. Efficiency versus Output Current, measured at TA = 25°C 26 24 22 20 18 16 14 12 10 8 6 4 2 0 MPM04: VO = 24 V, VIN = 36 V MPM04: VO = 18 V, VIN = 24 V MPM01: VO = 12 V, VIN = 24 V MPM01: VO = 5 V, VIN = 24 V MPM01: VO = 3.3 V, VIN = 12 V 0 0.5 1 1.5 2 IO (A) Figure 15. Load Regulation versus Output Current, measured at TA = 25°C MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 13 Estimated Lift Characteristics Generally, an electronic component will have shorter life cycle when used in high temperature. In order to use the IC for a long time, it is most effective to avoid overheating. Input voltage also dependency must be considered This section provides estimated use lifes when the IC is run continuously and when it is powered on and off repeatedly. 10000000 Mean Time to 0.1% Failure Rate (hours) 1000000 VIN = 24 VDC nominal 100000 10000 Temperature measurement point on the front side of the package temperature 6 mm 1000 13 mm 100 10 1 0 10 20 30 40 50 60 70 80 90 100 110 120 Package Surface Temperature (°C) Figure 16. Estimated life curve for input of 24VDC nominal continuous; and package temperature measuring point MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 14 Failure Acceleration Factor 100000 10000 1000 100 10 1 0.1 1 10 100 1000 Package Surface Temperature Change, ∆T (°C) Figure 17. Curve for mapping temperature change to Acceleration Factor for use in calculating IC lifetimes when power is cycled repeatedly Temperature Difference versus Acceleration Factor For the purposes of this experiment, a standard product lifetime, L0, was defined as 100 on-off cycles, and given the value 1. The change in temperature, ΔT, was calculated based on the package temperature measured at the point shown in figure 16. Although the package temperature can be lowered by derating the output current, in order to extend the expected lifetime, it is recommended to flow cooling air use over the device periodically, such as by assembling a heatsink to the device and forcing airflow using a blower or a fan. The estimated lifetime, L1 , is calculated using the following acceleration conditions: In addition, consider that it is required to connect electrolytic capacitors to the input and output of this product. Therefore, the life cycle of these electrolytic capacitors must be considered. Preventive maintenance may be required for these capacitors, according to the capacitor maker recommendations. L1 ≈ L0 × Acceleration Factor (14) If the change, ΔT, is 60°C, such as the temperature difference between 25°C and 85°C, it can read from figure 17 that it corresponds to an Acceleration Factor of approximately 20 times. To calculate the estimated lifetime, substitute into equation 14: L1 ≈ 100 × 20 ≈ 2000 temperature cycles MPM-AN Note: Sanken products are occasionally updated in order to provide better quality. Specification and application recommendations may be changed without a preliminary announcement to support product improvements. SANKEN ELECTRIC CO., LTD. March 2012 15 • The contents in this document are subject to changes, for improvement and other purposes, without notice. Make sure that this is the latest revision of the document before use. • Application and operation examples described in this document are quoted for the sole purpose of reference for the use of the products herein and Sanken can assume no responsibility for any infringement of industrial property rights, intellectual property rights or any other rights of Sanken or any third party which may result from its use. • Although Sanken undertakes to enhance the quality and reliability of its products, the occurrence of failure and defect of semiconductor products at a certain rate is inevitable. Users of Sanken products are requested to take, at their own risk, preventative measures including safety design of the equipment or systems against any possible injury, death, fires or damages to the society due to device failure or malfunction. • Sanken products listed in this document are designed and intended for the use as components in general purpose electronic equipment or apparatus (home appliances, office equipment, telecommunication equipment, measuring equipment, etc.). When considering the use of Sanken products in the applications where higher reliability is required (transportation equipment and its control systems, traffic signal control systems or equipment, fire/crime alarm systems, various safety devices, etc.), and whenever long life expectancy is required even in general purpose electronic equipment or apparatus, please contact your nearest Sanken sales representative to discuss, prior to the use of the products herein. The use of Sanken products without the written consent of Sanken in the applications where extremely high reliability is required (aerospace equipment, nuclear power control systems, life support systems, etc.) is strictly prohibited. • In the case that you use Sanken products or design your products by using Sanken products, the reliability largely depends on the degree of derating to be made to the rated values. Derating may be interpreted as a case that an operation range is set by derating the load from each rated value or surge voltage or noise is considered for derating in order to assure or improve the reliability. In general, derating factors include electric stresses such as electric voltage, electric current, electric power etc., environmental stresses such as ambient temperature, humidity etc. and thermal stress caused due to self-heating of semiconductor products. For these stresses, instantaneous values, maximum values and minimum values must be taken into consideration. In addition, it should be noted that since power devices or IC's including power devices have large self-heating value, the degree of derating of junction temperature affects the reliability significantly. • When using the products specified herein by either (i) combining other products or materials therewith or (ii) physically, chemically or otherwise processing or treating the products, please duly consider all possible risks that may result from all such uses in advance and proceed therewith at your own responsibility. • Anti radioactive ray design is not considered for the products listed herein. • Sanken assumes no responsibility for any troubles, such as dropping products caused during transportation out of Sanken's distribution network. • The contents in this document must not be transcribed or copied without Sanken's written consent. MPM-AN SANKEN ELECTRIC CO., LTD. March 2012 16