поискавой системы для электроныых деталей |
|
CS5132GDWR24 датащи(PDF) 8 Page - ON Semiconductor |
|
CS5132GDWR24 датащи(HTML) 8 Page - ON Semiconductor |
8 / 20 page minimizes inrush currents during regulator power-up, and switcher output enable. Start-up The CS5132 provides a controlled start-up of regulator out- put voltage and features Programmable Soft Start imple- mented through the Error Amp and external Compensation Capacitor. This feature, combined with overcurrent protec- tion, prevents stress to the regulator power components and overshoot of the output voltage during start-up. As Power is applied to the regulator, the CS5132 Undervoltage Lockout circuit (UVL) monitors the ICs sup- ply voltage (VCC) which is typically connected to the +12V output of the AC-DC power supply. The UVL circuit pre- vents the NFET gates from being activated until VCC exceeds the 8.4V (typ) threshold. Hysteresis of 300mV (typ) is provided for noise immunity. The Error Amp Capacitor connected to the COMP pin is charged by a 30µA current source. This capacitor must be charged to 1.06V (typ) so that it exceeds the PWM comparator’s offset before the V2 PWM control loop will permit switching to occur. When VCC has exceeded 8.4V and COMP has charged to 1.06V, the upper Gate driver (GATE(H)) is activated, turn- ing on the upper FET. This causes current to flow through the output inductor and into the output capacitors and load according to the following equation: I = (VIN – VOUT) x GATE(H) and the upper NFET remain on and inductor cur- rent ramps up until the initial pulse is terminated by either the PWM control loop or the overcurrent protection. This initial pulse of in-rush current minimizes start-up time, but does not overstress the regulator’s power components. The PWM comparator will terminate the initial pulse if the regulator output exceeds the voltage on the COMP pin minus the 1.06V PWM comparator offset prior to the drop across the current sense resistor exceeding the current limit threshold. In this case, the PWM control loop has achieved regulation and the initial pulse is then followed by a con- stant off time as programmed by the COFF capacitor. The COMP capacitor will continue to slowly charge and regula- tor output voltage will follow it, less the 1.06V PWM offset, until it achieves the voltage programmed by the DAC’s VID input. The Error Amp will then source or sink current to the COMP cap as required to maintain the correct regulator DC output voltage. Since the rate of increase of the COMP pin voltage is typically set much slower than the regulator’s slew capability, inrush current, output voltage, and duty cycle all gradually increase from zero. (See Figures 2, 3, and 4.) If the voltage across the Current Sense resistor generates a voltage difference between the VFFB and VOUT pins that exceeds the OVC Comparator Offset Voltage (86mV typi- cal), the Fault latch is set. This causes the COMP pin to be quickly discharged, turning off GATE(H) and the upper NFET since the voltage on the COMP pin is now less than the 1.06V PWM comparator offset. The Fault latch is reset when the voltage on the COMP decreases below the Discharge threshold voltage (0.25V typical). The COMP capacitor will again begin to charge, and when it exceeds the 1.06V PWM comparator offset, the regulator output will softstart normally (see Figure 5). Because the start-up circuitry depends on the current sense function, a current sense resistor should always be used. Figure 2: Normal Start-up (2ms/div). Channel 1 - Regulator Output Voltage (1V/div) Channel 2 - COMP Pin (1V/div) Channel 3 - VCC (10V/div) Channel 4 - Regulator Input Voltage (5V/div) Figure 3: Normal Start-up showing initial pulse followed by Soft Start (20µs/div). Channel 1 - Regulator Output Voltage (0.2V/div) Channel 2 – Inductor Switching Node (5V/div) Channel 3 - VCC (10V/div) Channel 4 - Regulator Input Voltage (5V/div) Start-up @ VCC > 8.4V Initial Pulse until VOUT > COMP - PWM Offset Start-up @ VCC > 8.4V T L Application Information: continued 8 |
Аналогичный номер детали - CS5132GDWR24 |
|
Аналогичное описание - CS5132GDWR24 |
|
|
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 |