CAPZero Family 1 Zero Loss Automatic X Capacitor Discharge IC Product Highlights R1 Blocks current through X capacitor discharge resistors when AC voltage is connected D1 Automatically discharges X capacitors through discharge resistors when AC is disconnected MOV Simplifies EMI filter design larger X capacitor allows smaller and Other AC X Capacitor EMI Filter inductive components with no change in consumption Components Only two terminals meets safety standards for use before or after system input fuse >4 mm creepage on package and PCB D2 CAPZero Self supplied no external bias required R2 High common mode surge immunity no external ground connection PI-6599-110711 High differential surge withstand 1000 V internal MOSFETs Figure 1. Typical Application Not a Simplified Circuit. EcoSmart Energy Efficient <5 mW consumption at 230 VAC for all X capacitor values Applications Component Selection Table All ACDC converters with X capacitors >100 nF Appliances requiring EuP Lot 6 compliance Total Series Maximum Total 3 2 Adapters requiring ultra low no-load consumption Product BV Resistance DSS X Capacitance All converters requiring very low standby power (R1 + R2) CAP002DG 825 V Description 500 nF 1.5 M W CAP012DG 1000 V When AC voltage is applied, CAPZero blocks current flow in the X capacitor safety discharge resistors, reducing the power loss to less CAP003DG 825 V 750 nF 1.02 M W 1 than 5 mW, or essentially zero at 230 VAC. When AC voltage is CAP013DG 1000 V disconnected, CAPZero automatically discharges the X capacitor by CAP004DG 825 V connecting the series discharge resistors. This operation allows total 1 mF 780 k W flexibility in the choice of the X capacitor to optimize differential mode CAP014DG 1000 V EMI filtering and reduce inductor costs, with no change in power CAP005DG 825 V consumption. 1.5 mF 480 k W CAP015DG 1000 V Designing with CAPZero is simply a matter of selecting the appropriate CAP006DG 825 V CAPZero device and external resistor values in Table 1 for the 2 mF 360 k W CAP016DG 1000 V X capacitor value being used. This design choice will provide a worst case RC time constant, when the AC supply is disconnected, of less CAP007DG 825 V 2.5 mF 300 k W than 1 second as required by international safety standards. CAP017DG 1000 V The simplicity and ruggedness of the two terminal CAPZero IC makes it CAP008DG 825 V 3.5 mF 200 k W an ideal choice in systems designed to meet EuP Lot 6 requirements. CAP018DG 1000 V The CAPZero family has two voltage grades: 825 V and 1000 V. The CAP009DG 825 V 5 mF 150 k W voltage rating required depends on surge requirement and circuit CAP019DG 1000 V configuration of the application. See Key Applications Considerations section for details. Table 1. Component Selection Table. Notes: 1. IEC 62301 clause 4.5 rounds standby power use below 5 mW to zero. 2. Values are nominal. RC time constant is <1 second with 20% X capacitor and 5% resistance from these nominal values. 3. Packages: D: SO-8. www.power.com July 2015CAPZero For MOV placement that is not directly across the X Capacitor1 (for Pin Functional Description example MOV in Figure 3) the 1000 V CAPZero devices can be POS2 The pin configuration of Figure 2 ensures that the width of the SO-8 used up to a surge specification of 1.5 kV. For differential surge package is used to provide creepage and clearance distance of over voltage specifications of >1.5 kV it is recommended that the MOV is 4 mm. always placed in the location shown in Figure 3 as MOV . POS1 Although electrical connections are only made to pins 2, 3, 6 and 7, it It is always recommended that the peak voltage between terminals is recommended that pins 1-4 and pins 5-8 are coupled together on D1 and D2 of CAPZero is measured during surge tests in the final the PCB see Applications Section. system. Measurements of peak voltage across CAPZero during surge tests should be made with oscilloscope probes having appropriate voltage rating and using an isolated supply to the oscilloscope to avoid ground currents influencing measurement results. When making such measurements, it is recommended that 50 V engineer- D Package (SO-8) ing margin is allowed below the breakdown voltage specification (for example 950 V with the 1000 V CAPZero). 1 8 NC NC If the measured peak Drain voltage exceeds 950 V, an external 1 kV 2 7 ceramic capacitor of value up to 47 pF can also be placed between D1 D1 D2 and D2 terminals to attenuate the voltage applied between the 3 6 D1 D2 CAPZero terminals during surge. This optional external capacitor 4 5 placement is shown as C in Figure 3. It should be noted that use NC NC EXT of an external capacitor in this way will increase power consumption slightly due to the C charge/discharge currents flowing in R1 and EXT R2 while AC is connected. A C value of 33 pF will add approximately EXT 0.5 mW at 230 VAC, 50 Hz. PI-5608-060810 PCB Layout and External Resistor Selection Figure 2. Pin Configuration. Figure 4 shows a typical PCB layout configuration for CAPZero. The external resistors in this case are divided into two separate surface Key Application Considerations mount resistors to distribute loss under fault conditions for example where a short-circuit exists between CAPZero terminals D1 and D2. Breakdown Voltage Selection R1 and R2 values are selected according to Table 1. Figure 3 illustrates possible system configurations influencing the choice of CAPZero breakdown voltage. The system configuration Under a fault condition where CAPZero terminals D1 and D2 are shorted together, each resistor will dissipate a power that can be variables include the placement of the system MOV and X capacitor(s) calculated from the applied AC voltage and the R1 and R2 values. For as well as the differential surge voltage specifications of the example in an application using CAP004 or CAP014, R1=R2=390 k W. application. If CAPZero is shorted out at 265 VAC R1 and R2 will each dissipate As shown in Table 1, each device in the CAPZero family has a 825 V 45 mW. or 1000 V option. For applications where the system MOV is placed Resistors R1 and R2 should also be rated for 50% of the system input in position 1 (MOV in Figure 3), the 825 V option will typically POS1 voltage again to allow for the short-circuitry of CAPZero D1 to D2 pins provide adequate voltage withstand for surge requirements up to 3 kV during single point fault testing. or more. The 1 kV CAPZero would be recommended for higher surge requirements or if additional voltage margin is required. R1 D1 MOV MOV POS1 POS2 Other EMI C EXT AC Filter Components X Capacitor1 X Capacitor2 D2 CAPZero R2 PI-6600-110711 Figure 3. Placement Options of MOV and C . EXT 2 Rev. G 07/15 www.power.com