Os motores de busca de Datasheet de Componentes eletrônicos |
|
FAN3240 Folha de dados(PDF) 16 Page - ON Semiconductor |
|
FAN3240 Folha de dados(HTML) 16 Page - ON Semiconductor |
16 / 21 page © 2011 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN3240 • Rev. 1.0.2 15 Figure 30. Operating Waveforms The FAN3241 produces fixed length output pulses as long as the incoming pulse width meets the qualification requirements. The timing details are shown in Figure 31. Figure 31. Timing Waveforms of the FAN3241 Similar to the previous example, the P1 measurement of the oscilloscope shows the length of the input command, IN_1. The tMAX duration is shown under the label P2 and tQUAL is measured under P5. The results show accurate timing performance for both factory programmable parameters. Applications Information The FAN324x significantly improves reliability and offers many protection functions that would be impractical to implement using discrete circuit components. In addition, it also greatly reduces component count and simplifies the relay drive circuit. A typical relay drive application is depicted in Figure 32. Input Connections The inputs of the relay driver can be directly driven from any appropriate signal source producing a TTL- compatible logic signal. The IN1 and IN2 inputs have 100 k Ω internal pull-down resistors, ensuring the off- state of the drive outputs during the high-impedance state of the source. This could happen during startup when a microcontroller is used to control the system. Enable Connection The enable (EN) pin of the device must be connected to the 5VB pin if it is not used. There is no pull-up or pull- down termination at this pin because any internal impedance might impact the accuracy of the comparator circuit when this pin is used for voltage monitoring. 5VB Bypass Recommendations The 5VB pin is the output of the internal bias regulator of the FAN324x. For stability of the negative feedback loop of the linear regulator and for noise filtering, a good quality high-frequency capacitor must be connected between this pin and the ground (GND) pin of the device. The recommended minimum capacitance is 100 nF. The capacitor should be placed near the 5VB and GND pins for best result. The output voltage of the on-board linear regulator is 5 V. This 5 V output can be used to power external circuitry. An example is shown in the application schematic of Figure 34 for isolated designs. The maximum guaranteed output current that can be used by external circuits is 5 mA; the regulator can deliver at least 5 mA to the external load and still meet all specifications listed in the parametric tables. 5VB Power Dissipation Considerations The output current of the 5VB bias regulator is supplied from the VS pin. While the recommended output current is 5 mA or less, the regulator is capable of sourcing significantly more current before its current limit is activated. Figure 10 of the typical performance characteristics curves shows the maximum current capability of the on-board linear regulator as a function of the input voltage and ambient temperature. If FAN324x is within recommended operating conditions (I5VB < 5 mA), the power dissipation of the regulator remains below 275 mW even at the highest operating voltage (60 V). However, at higher current levels, the power dissipation of the regulator and the thermal capabilities of the SOIC-8 package must be considered. At high input voltage levels (VS > 25 V) and currents over the guaranteed 5 mA level, the power loss of the on-board regulator might be high enough to elevate the junction temperature to the thermal protection shutdown threshold. If this occurs, the device shuts down to protect itself and functionality is lost until the junction temperature falls approximately 25°C (the thermal shutdown hysteresis). To preserve full functionality and reliable operation, it is recommended to check the output current rating of the linear regulator and to always calculate the power dissipation and the maximum temperature rise due to self heating. |
Nº de peça semelhante - FAN3240 |
|
Descrição semelhante - FAN3240 |
|
|
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 |