application

Common Mode and Differential Mode Filtering

Power DC input and output lines

communication device

computer equipment

feature

Complies with EU Directive 200295/EC

Compatible in lead-free or SnPb reflow environments

Small size: 50.8mm x 40.6mm x 12.7mm (2.0". x 1.6". x 0.50")

Optimized for high frequency dc-to-dc

power module

PCB mountable

Operating Box Temperature Range: –40°C to + 100 °C UL*60950 Recognized; CSA 8482 ; C22.2 No. 60950-00 Recognized; VDE 0805 (EN60950) Recognized CE Marked to 73/23/EEC and 93/68/ EEC Directive‡

illustrate

The FLTR100V20 filter module is designed to reduce conducted common and differential mode high frequency switching power supply input or output line noise. The module has a maximum current rating of 20 A. Provides High Insertion Loss Communications Commission (FCC) and International Special Committee on Radio Interference (CISPR) for conducted emissions over the entire U.S. federally mandated frequency range. The module measures 50.8 mm long, 40.6 mm wide, and 12.7 mm (2.0 inches) high. x 1.6 inches. x 0.50 inches) and mounted on a PC board in a natural convection or forced air environment. UL is a registered trademark of Underwriters Laboratories Inc. CSA is a registered trademark of the Canadian Standards Association. This product is intended for integration into end-use equipment. All procedures required for CE marking of terminal equipment shall be tracked. (CE marking is placed on selected products.)

introduce

High-density power modules are typically designed to operate at high switching frequencies to minimize internal filter components. Small EMI filters inside the module are often insufficient to meet stringent international EMI requirements. Many high-density electronic packaging techniques can increase the amount of noise conducted to the module's input and output lines. For example, switching components and input pins increase internal noise coupling; planar transformers, designed to handle high power levels in low-profile packages, have high inter-winding capacitances that can increase common-mode current levels. Also, metal substrates used to facilitate heat transfer from powertrain elements to external heat sinks increase common mode noise due to the large capacitance between the switching elements and the metal substrate. Many international agencies set limits for conducted and radiated emissions from electronic products. These include CISPR, FCC, VCCI and the new CE specification. Noise limits enforced by most agencies apply only to noise currents induced into AC power lines in the finished product. The European Telecommunications Standards Directive (ETSI) is an exception, applying CE requirements to DC power supplies with cable lengths over 3 meters. Although not required by agency standards, some system designers apply conducted emissions requirements to components within a product to reduce internal interference between subsystems and the difficulty of meeting overall system requirements. To meet these requirements, external filtering of the power module is usually required. The filter module is a filter optimized for use with F and J series power modules. With recommended external components and layout, conducted differential and common-mode noise back to the power supply will be significantly reduced. Use filters to meet CISPR and FCC Class B requirements as described in the following sections. Absolute Maximum Ratings Stresses in excess of the Absolute Maximum Ratings can cause permanent damage to the device. These are only absolute pressure ratings. at these or any other conditions exceeding those given in the operating section of the data sheet. Exposure to extended cycles at Absolute Maximum Ratings can adversely affect device reliability.

Electrical Specifications

Specifications apply to all operating input voltage and temperature conditions unless otherwise noted.

Features

Typical case temperature rise vs. Average current (case temperature must be kept below 100°C)

Fig. Typical Common Mode Insertion Loss Graph. Typical Differential Mode Insertion Loss in a 50/4 Circuit

Internal Schematic

application

Conducted noise on input power lines can occur from differential-mode or common-mode noise currents. Differential mode noise is on both input lines, mainly at the low frequency end of the spectrum. This noise appears as fundamental switching frequency noise harmonics. Measure common-mode noise broadband noise above 10 MHz between the input line and ground. The nature of high-frequency common-mode noise is primarily due to the high-speed switching of powertrain components. One or both types of noise may be included in the specification, as well as a combination of the two. A generally describes an approved measurement technique, as well. Differential mode noise is best attenuated with filters consisting of line-to-line capacitors (X capacitors) and series inductors, discrete inductors or the leakage inductance of common mode chokes. When adding the differential filtering module provided by the filter, it is recommended to install electrolytic capacitors on the converter side of the filter to provide additional attenuation of low frequency differential noise and to provide a low source impedance converter. This prevents input filter oscillations and load transients from inducing input voltage dips. Common mode noise is best attenuated with capacitors from the power module input to the power module output, capacitors (Y caps) and common mode chokes from each input line to the shield plane. It is recommended to add ceramic capacitors around each input and output pin to the shield plane under the module. The shield plane should be connected to the chassis pins. The ground pin of the filter module is connected to the Y cover inside the module. This pin should be tied to a quiet chassis ground point away from the power module.

The ground of the filter module should not be connected to the case pins of the power module, as this is the noise node and will inject noise into the filter, adding to the input common mode noise. If there is no quiet ground point, it is best to leave the filter module ground pins unconnected. The design of each power system will vary, and some experimentation may be required to arrive at the best configuration. Figure shows a typical schematic of a power module with filter module and recommended external components. Figure is a suggested layout. More than one power supply module can be connected to a single filter module as long as the input current does not exceed 20 A. Figure shows a schematic diagram of the recommended dual power supply modules connected to a single filter. Capacitors are not required in applications where the input is added to the output, do not use C3 and C4 as shown in the diagram and diagram, do not use C3, C4, C8 and C9 as shown. In -48 V applications, the shield plane and the power module case must be connected to the signal, remove C1 in the diagram and in the diagram, remove C1 and C6 in the diagram, and connect the shield plane and case pins to the VI(+) plane. In +48 V applications, the shield plane and the power module case must be connected to the signal, remove C2 in the diagram and in the diagram, remove C2 and C7 in the diagram, and connect the shield plane and case pins to the VI(–) plane .

NOTE: C1 to C4 can be 0.01µF to 0.1µF. Select the rated voltage to meet input and output isolation requirements. C5 should be the recommended value shown in the power module data sheet.

picture. Recommended schematic when used as input filter for high frequency dc-dc converters

NOTE: The Vdc input (+) and Vdc input (–) planes should overlap each other, as should the VI (+) and VI (–) planes, and the VO (+) and VO (–) planes should also overlap the planes. Avoid routing signals or planes under power modules or filter modules. Make sure all connections are low impedance.

picture. Recommended layout when used as input filter for high frequency dc-dc converters

NOTE: C1 to C4 and C6 to C9 can be 0.01 to 0.1 μF. Select the rated voltage to meet input and output isolation requirements. C5 should be the recommended value shown in the power module data sheet.

picture. Recommended illustration for filter modules with two power modules

Thermal factor

The case temperature must be kept below 100°C. Therefore, the airflow at the filter must be sufficient for a specific current and ambient temperature.

Example: Given: IO, max=18A; TA, max=40°C therefore yT, max allowable=60°C Determine the required airflow (Fig. 1): v=1.0 m/s (200 sqft)

Other considerations

In order to obtain good EMI performance, the input line passes through the filter without noise pollution. Therefore, filtered input traces should be kept away from noise sources such as power modules and switching logic lines. If the input voltage sense traces must pass through the power module from the quiet side of the filter module, it should be at the point where they leave the quiet input line. The input trace should be as far away from the output power trace as possible. The fundamental switching frequency noise spikes can be filtered by adding a high frequency capacitor of a few microfarads. Adding additional components to the input filter to improve performance usually pays off very limitedly and may increase conduction to the input row. Adding a Y-cap to the input of the filter block can couple any noise in the ground plane directly into the input line, often degrading performance. Adding additional X and Y capping filters to the power supply module side of the module creates a low impedance loop for high frequency currents that may degrade performance. Additional common-mode or differential-mode filtering of the power module output leads reduces power module output noise and reduces input noise by reducing noise coupled from the output leads to the input leads. Common mode output filtering is especially important if the load is limited to chassis ground. If common mode filtering is added to the power module output, make sure the remote control leads induce the output voltage before the common mode filter. Do not use the remote control output common mode filter on the load side. If the input noise performance is not ideal after using the filter block as described above, the remedy is to modify the layout and grounding scheme. It is often useful to make mockups of power cards, experimenting with copper tape and vector cards There are multiple layouts and grounds for printed circuit boards.

contour map

Dimensions are in millimeters and (inches).

Tolerance: xx±0.5 mm (0.02 in.), x.xx±0.25 mm (0.010 in.)

Post-weld cleaning and drying considerations

Post-solder cleaning is usually the final board

Assembly process before board testing

Improper cleaning and drying can affect

Complete circuit board assemblies for reliability and testability of power modules. For guidance on proper soldering, cleaning, and drying procedures, refer to Lineage Power Strip Mounting Power Modules: Soldering and Cleaning Application Notes. Through-Hole Lead-Free Soldering Information RoHS-compliant through-hole products use SAC (Sn/Ag/Cu) lead-free solder with RoHS-compliant components. They are designed to handle pins via single or dual wave soldering machines with a RoHS compliant surface finish and are compatible with both lead-free and lead-free wave soldering processes with a maximum preheat rate of 30C/s. The preheating process should keep the temperature of the temperature power module board below 2100C. For Pb solder, the recommended pot temperature is 2600C, while the lead-free solder pot is up to 2700C. All RoHS-compliant through-hole products can be processed by pasting through-hole lead or lead-free reflow soldering.