поискавой системы для электроныых деталей |
|
LM3622M-4.2 датащи(PDF) 6 Page - National Semiconductor (TI) |
|
|
LM3622M-4.2 датащи(HTML) 6 Page - National Semiconductor (TI) |
6 / 9 page Functional Description The simplified LM3622 block diagram in Figure 1 gives a general idea of the circuit operation. The controller integrates the reference, feedback and drive functions on-chip to con- trol a linear, lithium-ion battery charger in constant voltage and constant current (CVCC) charge operation. The regu- lated output voltage is sensed between CEL and CS, and the battery charge current is sensed across a current-sense re- sistor between CS and GND. The EXT pin is designed for driving a series pass element, which can be a PNP transistor or a P-MOSFET. Tying the LV ENB pin to ground enables the controller’s low-voltage detection circuit. When the low-voltage detection circuit is enabled and a battery voltage below a preset threshold is detected, the LM3622 will drive the LV pin low and shut off the current flowing into the EXT pin to suspend the CVCC charge process. The low-voltage threshold is user selectable to be either 2.15V/cell or 2.7V/cell by pulling the LV SEL pin to GND or VCC respectively. The LV pin is a NPN open collector output that can be used to turn on a low cur- rent source to wake up charge a deeply depleted battery. When the low-voltage detection is disabled (LV ENB pulled up to V CC), the LM3622 always starts the charge cycle in con- stant current mode at any battery voltage below the control- ler’s regulation level, and maintains the LV pin at a high-impedance state. Application Information CEL Pin Current Drain The LM3622 has an internal power down switch in series with the on-chip resistor divider that is used for sensing the battery voltage. In the event that the V CC supply is removed, the power down switch will disconnect the resistor divider from the CS pin, preventing the battery from discharging through the CEL pin. EXT Pin The EXT pin is internally pulled up to V CC via a 20µA current source making it possible to eliminate the external base-emitter resistor when driving a PNP transistor, or the gate-source resistor when driving a P-MOSFET. However, the voltage applied to EXT is not allowed to be higher than (V CC + 0.3V), otherwise the reverse current from EXT pin to V CC pin may cause damage to the device. LV Pin Current Rating The LV pin is a low power, NPN open collector output that is rated to sink 10mA maximum. Therefore, the value of the pull up resistor should be chosen high enough to limit the current to be less than 10mA. CS Pin In normal operation, the current limit threshold voltage for the CS pin is 100mV typical. In case of a fault condition, the voltage to this pin should be limited to below 5V. DS100974-11 FIGURE 1. LM3622 Simplified Block Diagram www.national.com 6 |
Аналогичный номер детали - LM3622M-4.2 |
|
Аналогичное описание - LM3622M-4.2 |
|
|
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 |