Os motores de busca de Datasheet de Componentes eletrônicos |
|
CS5231-3GDP5 Folha de dados(PDF) 10 Page - ON Semiconductor |
|
CS5231-3GDP5 Folha de dados(HTML) 10 Page - ON Semiconductor |
10 / 14 page CS5231−3 http://onsemi.com 10 First, we determine the need for heatsinking. If we assume the maximum qJA = 50 °C/W for the D2PAK, the maximum temperature rise is found to be DT + PD qJA + 1.018 W 50 °C W + 50.9°C This is less than the maximum specified operating junction temperature of 125 °C, and no heatsinking is required. Since the D2PAK has a large tab, mounting this part to the PC board by soldering both tab and leads will provide superior performance with no PC board area penalty. TYPICAL FUSED SOIC−8 DESIGN We first determine the need for a heat sink for the SOIC−8 package at a load of 500 mA. Using the dissipation from the D2PAK example of 1018 mW and the qJA of the SOIC−8 package of 110 °C/W gives a temperature rise of 112°C. Adding this to an ambient temperature of 70 °C gives 182°C junction temperature. This is an excessive temperature rise but it can be reduced by adding additional cooling in the form of added surface area of copper on the PCB. Using the relationship of maximum temperature rise of DTJA + TJ(MAX) * TA + 150°C * 70°C + 80°C We calculate the thermal resistance allowed from junction to air: qJA(worst case) + DTJA PD + 80°C 1.018 W + 79.6°C W The thermal resistance from the die to the leads (case) is 25 °C/W. Subtracting these two numbers gives the allowable thermal resistance from case to ambient: qCA + qJA * qJC + 79.6°C W * 25°C W + 54.6°C W The thermal resistance of this copper area will be 54.6 °C/W. We now look at Figure 20 and find the PCB trace area that will be less than 54.5 °C/W. Examination shows that 750 mm2 of copper will provide cooling for this part. This would be the SOIC−8 part with the center 4 ground leads soldered to pads in the center of a copper area about 27 mm × 27 mm. A lower dissipation or the addition of air−flow could result in a smaller required surface area. DESCRIPTION The CS5231−3 application circuit has been implemented as shown in the following pages. The schematic, bill of materials and printed circuit board artwork can be used to build the circuit. The design is very simple and consists of two capacitors, a p−channel FET and the CS5231−3. Five turret pins are provided for connection of supplies, meters, oscilloscope probes and loads. The CS5231−3 power supply management solution is implemented in an area less than 1.5 square inches. Due to the simplicity of the design, output current must be derated if the CS5231−3 is operated at VIN voltages greater than 7.0 V. Figure 21 provides the derating curve on a maximum power dissipation if heatsink is added. Operating at higher power dissipation without CS5231−3 heatsink may result in a thermal shutdown condition. Figure 21. Demo Board Output Current Derating vs. VIN VIN (Volts) 5 6 500 600 400 300 200 100 0 78 9 10 11 12 13 14 The VIN Connection The VIN connection is denoted as such on the PC board. The maximum input voltage to the IC is 14 V before damage to the IC is possible. However, the specification range for the IC is 4.75 V < VIN < 6.0 V. The GND Connection The GND connection ties the IC power return to two turret pins. The extra turret pin provides for connection of multiple instrument grounds to the demonstration board. The AuxDrv Connection The AuxDrv lead of the CS5231−3 is connected to the gate of the external PFET. This connection is also brought to a turret pin to allow easy connection of an oscilloscope probe for viewing the AuxDrv waveforms. The VAUX Connection The VAUX turret pin provides a connection point between an external 3.3 V supply and the PFET drain. The VOUT Connection The VOUT connection is tied to the VOUT lead of the CS5231−3 and the PFET source. This point provides a convenient point at which some type of lead may be applied. Figure 22. Application Circuit Schematic TP5 TP6 AuxDrv TP1 TP2 TP3 TP4 VAUX +3.3 V C2 Q1 U1 VOUT VIN GND AuxDrv CS5231−3 VIN GND C1 |
Nº de peça semelhante - CS5231-3GDP5 |
|
Descrição semelhante - CS5231-3GDP5 |
|
|
Ligação URL |
Privacy Policy |
ALLDATASHEETPT.COM |
ALLDATASHEET é útil para você? [ DONATE ] |
Sobre Alldatasheet | Publicidade | Contato conosco | Privacy Policy | roca de Link | Lista de Fabricantes All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |