APA501. Series AMPSS. Heatsinks for Power Modules Technical Reference Manual. Series Highlights

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1 AMPSS Astec Modular Power Supply System APA5 Series Heatsinks for Power Modules Technical Reference Manual Series Highlights Horizontal, Vertical and Low Profile fin options Full range of mounting accessories

2 Contents Heatsinks... 3 "6" Size Heatsink Dimensions & Characteristics... 4 "8" Size Heatsink Dimensions & Characteristics... 7 Thermal Design Process and Example... Rev. Jan 96 Table of Contents

3 Heatsinks Heatsinks for AMPSS modules are available in a variety of sizes and fin orientation. Mounting kits and thermal pads are also available. The table below shows the options available for "8" and "6" module sizes. A heatsink mounting kit provides the most convenient way to mount the heatsink to the module and then mount the assembly onto a circuit board AMPSS modules may be retained by their input and output pins only, or may be fixed to the board using bolts screwed into the tapped studs which are provided as part of the mounting kit. In both cases the studs provide clearance between the module and the circuit board to facilitate PCB cleaning operations. Note: baseplate and heatsink must be connected to protective earth 2 Description Model Number Dimensions Free air thermal inches mm resistance Heatsink, "6" size, vertical fin. APA x2.32x x59x5 3.8 C/W Heatsink, "6" size, horizontal fin APA x2.32x x59x5 3.9 C/W Heatsink, "6" size, vertical fin. APA x2.32x x59x C/W Heatsink, "6" size, horizontal fin APA x2.32x x59x C/W Heatsink, "6" size, vertical fin. APA x2.32x x59x C/W Heatsink, "6" size, horizontal fin APA x2.32x x59x C/W Heatsink, "6" size, low profile APA x3.5x x89x2 3.6 C/W Heatsink, "8" size, vertical fin. APA x2.32x.6 5x59x5 2.7 C/W Heatsink, "8" size, horizontal fin APA x2.32x.6 5x59x5 2.4 C/W Heatsink, "8" size, vertical fin. APA x2.32x.9 5x59x C/W Heatsink, "8" size, horizontal fin APA x2.32x.9 5x59x C/W Heatsink, "8" size, vertical fin. APA x2.32x.5 5x59x37 2. C/W Heatsink, "8" size, horizontal fin APA x2.32x.5 5x59x37.7 C/W Heatsink, "8" size, low profile APA x3.5x.5 5.6x89x2 2.2 C/W Thermal Pad, "6" size APA52-6- Thermal Pad, "8" size APA52-8- Mounting Kit, Tapped Studs APA53-- Mounting Kit, Solder Studs APA53--2 Mounting Kit, Tapped Studs APA53--7 for low profile heatsink Mounting Kit, Solder Studs APA53--8 for low profile heatsink Spring Sockets (2 cont. 5pwr) APA54-- Rev. Jan 96 3AMPSS Accessories

4 Heatsinks "6" Size Heatsink Dimensions & Characteristics APA5-6- ø 3.8 (.5) (.9) 57.5 (2.26) 4. (.6) 2. (.47) 5.8 (2.) 5. (.6) 59. (2.32) Forced Convection for APA5-6- at W Output APA5-6-2 ø 3.8 (.5) 2.5 Forced Convection for APA5-6-2 at W Output (.9) 57.5 (2.26) 4. (.6) 2. (.47) 5.8 (2.) 5. (.6) 59. (2.32) APA5-6-3 ø 3.8 (.5) Forced Convection for APA5-6-3 at W Output (.9) 57.5 (2.26) 4. (.6) 2. (.47) 5.8 (2.) 59. (2.32) 24. (.9) Rev. Jan 96

5 APA5-6-4 ø 3.8 (.5) Forced Convection for APA5-6-4 at W Output (.9) 57.5 (2.26) 2. (.47) 5.8 (2.) 59. (2.32) 24. (.9) (.6) APA5-6-5 APA5-6-6 Rev. Jan 96 ø 3.8 (.5) (.9) 57.5 (2.26) ø 3.8 (.5) (.9) 57.5 (2.26) 5.8 (2.) 59. (2.32) 4. (.6) 2. (.47) 4. (.6) 5.8 (2.) 2. (.47) 37. (.5) 59. (2.32) 37. (.5) Forced Convection for APA5-6-5 at W Output Forced Convection for APA5-6-6 at W Output AMPSS Accessories

6 Heatsinks APA5-6-7 A 57.2 (2.25) 5.8 (2.) 9. (.75) 4.47(.8) (.9) A Forced Convection for APA5-8-7 at 2W Output (.6) ±. ø7.5 (.3) (4X) ø3.8 (.5) (4X) 2. (.47) 4.2 (.7) 3.5 (.4) ø4.2 (.7) (4X) 63. (2.48) 89. (3.5) Section A-A 6 Rev. Jan 96

7 "8" Size Heatsink Dimensions & Characteristics APA5-8- ø 3.8 (.5) Forced Convection for APA5-8- at 2W Output (4.2) 5. (4.53) APA5-8-2 ø 3.8 (.5) 6.68 (4.2) 5. (4.53) Rev. Jan (.47) 4. (.6) 2. (.47) 4. (.6) 5.8(2.) 59. (2.32) 5.8(2.) 59. (2.32) 5. (.6) 5. (.6) Forced Convection for APA5-8-2 at 2W Output AMPSS Accessories

8 Heatsinks APA5-8-3 ø 3.8 (.5) 6.68 (4.2) 5. (4.53) 2. (.47) 5.8(2.) 59. (2.32) Forced Convection for APA5-8-3 at 2W Output (.6) 22.5 (.89) APA5-8-4 ø 3.8 (.5) Forced Convection for APA5-8-4 at 2W Output (4.2) 5. (4.53) 5.8(2.) 59. (2.32) (.6) 22.5 (.89) 2. (.47) 8 Rev. Jan 96

9 APA5-8-5 ø 3.8 (.5) Forced Convection for APA5-8-5 at 2W Output (4.2) 5. (4.53) 5.8(2.) 59.(2.32) 2. (.47) APA5-8-6 ø 3.8 (.5) 6.68 (4.2) 5. (4.53) Rev. Jan (.6) 2. (.47) 37. (.5) 5.8(2.) 59.(2.32) 4. (.6) 37. (.5) Forced Convection for APA5-8-6 at 2W Output AMPSS Accessories

10 Heatsinks APA (4.55) ± (2.) 9. (.75) 4.47 (.8) 6.68 (4.2) Forced Convection for APA5-8-7 at 2W Output A A 4.2 (.7) 3.5 (.4) 4. (.6) ±. 45 ø7.5 (.3) (4X) ø3.8 (.5) (4X) 2. (.47) ø4.2 (.7) (4X) 63. (2.48) 89. (3.5) Section A-A Rev. Jan 96

11 Thermal Design Process and Example Temperature & MTBF APMSS modules are designed to be able to run at baseplate temperatures of C in the case of the AM8 series and 85 C for other series. However, for normal operation the modules should not be run at the maximum allowable temperature since the Mean Time Between Failures (MTBF) will reduce sharply as temperature increases. For example, an AM8-3L-5F4 operating at 5V@4A output, with a baseplate temperature of 5 C, has an MTBF of over one million hours. If the temperature is doubled to C this figure drops to 55, hours. The following rules should be followed to ensure reliable operation - At the maximum system ambient temperature the APMSS baseplate temperature rating should not be exceeded. At the normal system ambient operating temperature the APMSS baseplate temperature must be low enough to meet MTBF requirements. The Thermal Design Process. Determine heat generated by module from its losses. The minimum efficiency at relevant line and load conditions should be used in calculating the losses. 2. Determine maximum baseplate temperature rise to stay within module temperature rating at maximum system ambient. 3. Define maximum system baseplate temperature to meet MTBF in normal system operating conditions or at the temperature at which the MTBF is specified. 4. Select/design heatsink and airflow requirement. 5. Test using the APMSS imbedded TEMP-MON feature which allows direct and convenient monitoring of baseplate temperature. (BM/AM/ AL/AK Series). Heat generated = Power Out x [(/Efficiency)-] = 5 x [(/.83)-] = 3 Watt 2. Maximum baseplate temperature C (from AM8 specifications). At 6 C (max. ambient temp.) the maximum baseplate temperature rise is 4 C. 3. To achieve 8, hours MTBF, baseplate temperature must not exceed 6 C. Maximum baseplate temperature rise (from 25 C operating ambient) is 36 C. 4. Choose the lowest temperature rise of ➁ or ➂ i.e. 36 C. The cooling system must dissipate 3 Watts with a maximum baseplate temperature rise of 36 C. Thermal resistance = 36/3 =.6 C/Watt. To ensure good thermal contact Astec recommends the use of Thermstrate thermal mounting pads. Thermal resistance of the Thermstrate interface between baseplate and heatsink is. C/W. For this example (overall thermal resistance.6 C/ W) the heatsink thermal resistance should be a maximum of.6 C/W. A % safety margin is desirable so a heatsink achieving.95 C/W is chosen. To achieve this level of cooling using natural convection would require an very large heatsink. It would therefore be better to employ forced air cooling. A thermal resistance vs air flow characteristic should be referenced to determine the required airflow for the heatsink you are using. AMPSS Accessories Thermal Design Example This example is for the following parameters: Single 5V AM8 module used in a distributed power system. Average load 3A (5 Watts) Normal operating ambient temperature 25 C Maximum ambient temperature 6 C MTBF required - 8, hours (from system requirements) Efficiency measured at 83% (Efficiency = Output power/ Input power) Rev. Jan 96

12 Heatsinks Tips on installation of AMPSS modules.ensure that the module/heatsink interface smooth, flat and free of debris. Always use either thermal grease or APMSS thermal pads. 2. Fit modules and other heat generating devices at the top of the cabinet where possible. 3. Stagger modules to improve cooling and facilitate even heat distribution between modules. AIRFLOW AIRFLOW 4. Avoid blocking the airflow to the modules with other components. AIRFLOW AIRFLOW 5. Use a heatsink with fins running vertically for natural convection cooling. 2 Rev. Jan 96

13 For further information contact : NORTH AMERICA ASTEC AMERICA, INC. 58 Van Allen Way Carlsbad, CA 928 USA Tel : Fax : EUROPE ASTEC EUROPE LTD. Astec House, Waterfront Bus. Park Merry Hill, Dudley West Midlands DY5 LX U.K. Tel : Fax : ASIA ASTEC ASIA 6F., China Dyeing Works Building Castle Peak Road Tsuen Wan N.T. Hong Kong Tel : Fax : APA7-VRM Rev. 4 May 97

LMM-H03 Mass Air FLow Sensor

LMM-H03 Mass Air FLow Sensor Mass Air FLow Sensor Product Description LMM-H03 is a thermodynamic sensing element for the bidirectional measurement of mass air flow in a well defined channel. It is dedicated for applications with high