поискавой системы для электроныых деталей |
|
L6599ATN датащи(PDF) 6 Page - STMicroelectronics |
|
L6599ATN датащи(HTML) 6 Page - STMicroelectronics |
6 / 31 page Pin connection L6599AT 6/31 Doc ID 15534 Rev 3 4RFmin Minimum oscillator frequency setting. This pin provides a precise 2 V reference and a resistor connected from this pin to GND defines a current that is used to set the minimum oscillator frequency. To close the feedback loop that regulates the converter output voltage by modulating the oscillator frequency, the phototransistor of an optocoupler is connected to this pin through a resistor. The value of this resistor sets the maximum operating frequency. An R-C series connected from this pin to GND sets frequency shift at start-up to prevent excessive energy inrush (soft-start). 5STBY Burst-mode operation threshold. The pin senses some voltage related to the feedback control, which is compared to an internal reference (1.24 V). If the voltage on the pin is lower than the reference, the IC enters an idle state and its quiescent current is reduced. The chip restarts switching as the voltage exceeds the reference by 50 mV. Soft-start is not invoked. This function realizes burst-mode operation when the load falls below a level that can be programmed by properly choosing the resistor connecting the optocoupler to pin RFmin (see block diagram). Tie the pin to RFmin if burst-mode is not used. 6 ISEN Current sense input. The pin senses the primary current though a sense resistor or a capacitive divider for lossless sensing. This input is not intended for a cycle-by-cycle control; hence the voltage signal must be filtered to get average current information. As the voltage exceeds a 0.8 V threshold (with 50 mV hysteresis), the soft-start capacitor connected to pin 1 is internally discharged: the frequency increases hence limiting the power throughput. Under output short-circuit, this normally results in a nearly constant peak primary current. This condition is allowed for a maximum time set at pin 2. If the current keeps on building up despite this frequency increase, a second comparator referenced at 1.5 V latches the device off and brings its consumption almost to a “before start-up” level. The information is latched and it is necessary to recycle the supply voltage of the IC to enable it to restart: the latch is removed as the voltage on the Vcc pin goes below the UVLO threshold. Tie the pin to GND if the function is not used. 7LINE Line sensing input. The pin is to be connected to the high-voltage input bus with a resistor divider to perform either AC or DC (in systems with PFC) brownout protection. A voltage below 1.24 V shuts down (not latched) the IC, lowers its consumption and discharges the soft-start capacitor. IC’s operation is re-enabled (soft-started) as the voltage exceeds 1.24 V. The comparator is provided with current hysteresis: an internal 13 µA current generator is ON as long as the voltage applied at the pin is below 1.24 V and is OFF if this value is exceeded. Bypass the pin with a capacitor to GND to reduce noise pick-up. The voltage on the pin is top-limited by an internal zener. Activating the zener causes the IC to shut down (not latched). Bias the pin between 1.24 and 6 V if the function is not used. 8DIS Latched device shutdown. Internally the pin connects a comparator that, when the voltage on the pin exceeds 1.85V, shuts the IC down and brings its consumption almost to a “before start-up” level. The information is latched and it is necessary to recycle the supply voltage of the IC to enable it to restart: the latch is removed as the voltage on the Vcc pin goes below the UVLO threshold. Tie the pin to GND if the function is not used. Table 2. Pin description (continued) Pin n° Type Function |
Аналогичный номер детали - L6599ATN |
|
Аналогичное описание - L6599ATN |
|
|
ссылки URL |
Конфиденциальность |
ALLDATASHEETRU.COM |
Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | обмен ссыками | поиск по производителю 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 |