Zakładka z wyszukiwarką danych komponentów |
|
TS3405 Arkusz danych(PDF) 6 Page - Taiwan Semiconductor Company, Ltd |
|
TS3405 Arkusz danych(HTML) 6 Page - Taiwan Semiconductor Company, Ltd |
6 / 10 page Functional Description Start Up The TS3405 automatically initializes upon receipt of power. The Power-On Reset (POR) function continually monitors the bias voltage at the Vcc pin. The POR function initiates the Soft Start (SS) operation after the supply voltage exceeds its POR threshold. Over Current Protection (OCP) The over current function protects the converter from a shorted output by using the lower MOSFET’s on-resistance, Rds(on), to monitor the current. Therefore, even the power input voltage is greater than Vcc, TS3405 still can support this. This method enhances the converter’s efficiency and reduces cost by eliminating a current sensing resistor. The TS3405’s OCP threshold is a fixed value, -300mV, when Phase voltage is less –300mV, the next on-cycle will not be initialized. Over Voltage Protection (OVP) An over voltage protection comparator is monitoring the COMP. When COMP voltage is less than 0.3V, the Soft Start (SS) process is initiated. Soft Start (SS) Both POR and OVP initiate the soft start sequence after the over current set point has been sampled. Soft Start clamps virtually the error amplifier output (COMP pin) and reference input (non-inverting terminal of the error amp) to the internally generated Soft Start voltage. The oscillator’s triangular waveform is compared to the ramping error amplifier voltage. This generates Phase pulses of increasing width that charge the output capacitor(s). when the internally generated Soft Start voltage exceeds the COMP pin voltage, the output voltage is in regulation. This method provides a rapid and controlled output voltage rise. The entire startup sequence typically takes about 5mS. Current Sinking The TS3405 incorporates a MOSFET shoot-through protection method which allows a converter to sink current as well as source current. Care should be exercised when designing a converter with the TS3405 when it is known that the converter may sink current. When the converter is sinking current, it is behaving as a boost converter that is regulating its input voltage. This means that the converter is boosting current into the buck converter input power, if the buck converter input power has the same supply source which supplies the bias voltage, Vcc to the TS3405. if there is nowhere for this current to go, such as to other distributed loads on the Vcc rail, through a voltage limiting protection device, or other methods, the capacitance on the Vcc bus will absorb the current. This situation will allow voltage level of the Vcc rail to increase. If the voltage level of the rail is boosted to a level that exceeds the maximum voltage rating of the TS3405, then the IC will experience an irreversible failure and the converter will no longer be operational. Ensuring that there is a path for the current to follow other than the capacitance on the rail will prevent this failure mode. TS3405 6-10 2003/12 rev. A |
Podobny numer części - TS3405 |
|
Podobny opis - TS3405 |
|
|
Link URL |
Polityka prywatności |
ALLDATASHEET.PL |
Czy Alldatasheet okazała się pomocna? [ DONATE ] |
O Alldatasheet | Reklama | Kontakt | Polityka prywatności | Linki | Lista producentów 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 |